Hayduke's Operation Comanche Repower - 88 To 98 Swap

[GHayduke]

I got the shaft !

I came home to treasure on the front steps today.  My Tom Wood's driveshaft, my front Axle seals, and a Chero Haynes manual... too bad the door switches didn't arrive so I could start troubleshooting the electrical.

 

I installed my old stub shaft off the transfercase (because all they had was used ones anyway- this saved me some cost). I then buttoned up the fuel sender wiring confirming color codes via Alexia's post (his post confirmed how I already had wired it :thumbsup:  ), and tied the wires up out of the way. I then installed the driveshaft. 

 

 

The clearance between the driveshaft and gas tank is very adequate, I'd guess two inches or more.  I started to mount the factory MJ muffler & exhaust, but the old set up is about 5 inches too long.  I just ordered a XJ muffler (around 22 inchs long vs. 25-1/2) and will trim some off the tailpipe. The old muffler was rough anyway....

 

[GHayduke]

Need Electrical Help!  Where to troubleshoot next???

 
When I got the crashed donor XJ, the dome light stayed on all the time regardless of the switches position.
 
Quoted from earlier:  " Another related & weird issue is the jeep does not prime the fuel pump/run, if the drivers door is closed. (works fine opened).  & if the door is closed while running- the engine runs poorly or dies....  I'm assuming the door switch must be bad & creating a short or ground to something..???? " 
 

First off, I'm new to this wiring.  I've worked with 80's and older car wiring plenty, but this 98' is a different amimal...

 

I know Alexia said I can ground the fuel pump to the body & I might do that (in addition), but it seems like a work around & not solving a bigger issue... & I want my dome lights etc to function too...

I recieved the new door switches and installed them, but the issue was not resolved.  I'm using the XJ harness and switches.  I tested each switch compared toan old switch and they all work the same: all three wires are disconnected (switch presed) until switch pops out, then all three connect.  None of the switch harness cables show continuity (or ground) to the body. 
 
I checked continuity & power at the drivers side main harness plug, ingition off: the side BLK wire/pin show ground, the middle pin/ Blk w/blue strip wire shows 4.44volts & not grounded.  Voltage is seen between either outer pin bridged to inside pin as well as to a body ground.  I'll retest Yellow as I though I saw ground once??
 
If the key is in ignition, the warning beeper works when door is opened (switch out/closed) but no dome light/ or floor lamps.  The dome lamp bulb looks good, floor bulbs may be burned out?  The manual dome light side courtesy lamps work if turned on.

 

Passenger side switch:  I tested the switch and it workes correctly or as the driver side does. At the interior harness the plug only uses to outer two wires.  There does not seem to be any continuity or power when bridging these wires. Blk wire shows groud, yellow does too.  Maybe just bridging / grounding a circuit?

 

From the basic wiring diagram I'm guessing the yellow shouldn't be grounded? where to start?

 

Possiblly related?:  I plugged in the rear lighting/turn signal harnesses to the factory plugs, and wired up the nose (or tried too). when the ingition is on, one rear bulb is always lite, even if I ground the stray body ground? I figured it might be related to the door switch issue so I stopped & went back to the door switch circuit testing....

 

I'll add more if I discover anything new.... But I'm not sure where to test next.  Any help would be appreaciated as always!!!

 

I'm so close to having the project on the road if I could solve the electrical issues.

[GHayduke]

Still not working..

Update.. backed up and did some more basic testing.  First I replaced all the bulbs (floor, dome. & back dome).  Then I connected door switches to all 4 plugs (included the rears) no difference.  I disconnected all the door switches and the dome light harness.  I tested the yellow dome wire to see if it was ground/-. No, no continuity between the yellow at any plugs for switches or harness..including door switches. So looks like yellow is not grounded?

 

Once I connect a door switch, then the yellow has continuity with the body/ground.... I checked the headlight switch and I can turn on the front dome and floor lights manually by turning the nob.  But no lights otherwise?

 

Next I tried running a ground wire from the fuel pump negative wire to a seat stud.  That stops the running issue, but not the interior lights issue.  Also the rear XJ dome light (now in the back wall) plugged into it's original harness plug does not light at all.

 

I still don't have working needle guages on dash either.  I pulled the dash cover and confirmed the plugs behind the cluster are plugged in well. When I first ran the engine the guages were working?  Is there a circuit breaker or relay I need to check?

 

I tried checking all the under dash plugs I could reach? didn't resolve the issue.

 

I'm getting really tired of playing with these plugs! :doh:

 

[GHayduke]

After talking with some friends I went on a Ground Attack.  I checked all the grounds in the engine bay and on the floor of the cab.

The OHM meter said I have 0.4 ohms of resistance on the worst connections.  I also added a 10 guage ground line into the cab (for the heated seats and other accessories) and twinned it in with the other grounds... Still did not solve the issue.  Are there other grounds I'm forgetting?

 

I started the engine and noted what does not work now:  Guages, Radio, heater controls, dome lights.... seems like a bigger issue. What connectors, relay's etc should I check?

[Akula69]

The tail lights on Ryan's truck behaved the same as yours are initially, and we ended up extending a ground from the cab harness (it was on the original XJ harness going to the back down the passenger side to the junction block inside the quarter panel), to the frame near the X member. We cleaned the paint/primer off and confirmed 'good ground' (ran jumper to + battery terminal for one multimeter lead and then touched the frame with he other lead) and screwed it in. Immediately the tail lights stopped the 'dim' illumination and worked properly. This ground was also the one that ran to the fuel pump (from the same splice inside the cab).

 

We messed with the door switches for a long time before realizing the circuit is (1) closed circuit (without body ground in the cab) (2) looped with the two lights under the dash, the visor mirror illumination, and the (XJ) rear door switches and rear hatch switch and (3) a huge PITA. There are two fuses in the PDA and one in the passenger side kick panel for the interior lights - all 15 AMP minis.

For the time being (and the reduce your stress) disconnect the harness plugs for the interior lights (at all locations) and then check for good ground at the fuel pump. You might need to establish a direct ground to the frame by the battery (- battery terminal to inner fender) if you do not have one to ensure frame grounds.

One of the ways the dealer techs 'check' for good, full wire continuity in wiring is to take a regular headlight bulb and run one lead directly to the battery (or to the hot wire in the circuit) from the low beam + side and the other is on the - side of the bulb and touched to the ground lead. If you have continuity with just a few wire strands it will illuminate dimly - it you have full continuity it will be on full. Be extremely careful doing this - bulb will get hot quickly!

[GHayduke]

We messed with the door switches for a long time before realizing the circuit is (1) closed circuit (without body ground in the cab) (2) looped with the two lights under the dash, the visor mirror illumination, and the (XJ) rear door switches and rear hatch switch and (3) a huge PITA. There are two fuses in the PDA and one in the passenger side kick panel for the interior lights - all 15 AMP minis.

For the time being (and the reduce your stress) disconnect the harness plugs for the interior lights (at all locations) and then check for good ground at the fuel pump. You might need to establish a direct ground to the frame by the battery (- battery terminal to inner fender) if you do not have one to ensure frame grounds.

 

Thanks Akula69:  I grounded the fuel pump to the cab floor & to a 10 guage ground wire running from the battery fender negative bolt.  I decided to run a 10 guage pos & neg to the cab for the heated power seats and future accesories. 

 

You said the door switch circuit includes "the visor mirror illumination, and the (XJ) rear door switches and rear hatch switch"  when I get this working will the rear door plugs and/or the rear hatch switch plug need anything connected to them????  I didn't realize the rear hatch switch was even in the mix.

 

Tonight I'm going to check the G108 dash grounds I didn't know where there & check some other stuff....

[Akula69]

The short answer is no, when your short is solved nothing needs to be plugged into them...but if the short is on one of those circuits it will be there until you resolve it.

 

In our case, through trial and error we eliminated the plugs on the harness for the rear door switches and the hatch switch, but we solved the shorting problems first (to make sure what we did during elimination of the plugs did not aggravate the problem). We cut all the loom away and traced the wires back to the closest splices and trimmed them there. We used this method to not only eliminate the rear door switches, but also the rear door lock/electric window plugs as well.

[GHayduke]

Sounds good.  But I'm still fighting the new bigger electrical issue- dash power, no guages, radio, or heater control power.  I checked and enhanced the G108 grounds for the radio & cluster by adding a additional ground wire from them to the firewall.  I disconnected the dome light as I read a failed circuit board there can cause havoc, and rechecked fuses.  I then exposed the Ingintion switch, but don't know how to test it??? Any ideas!  this one has me really at wit's end.

[Akula69]

My first thought would be to check that you have the three large (rectangular in shape) plugs under the dash seated properly. Remember the "no bUs" problem we had was related to a plug that 'clicked' together but was not seated properly. There are two beside the D/S kick panel and one just to the left of and above the gas pedal. Also, be sure and check all the fuses / relays in the panel on the P/S.

[GHayduke]

I checked and cleaned all connectors and checked pass side dash grounds & replugged in fuse box plugs.  Found loose fuse box plugs.  I now have radio, heater, and odometer back, but still not needle guages. Diagnostic test of cluster now shows whole cluster works.  No check engine lights but checked for codes anyway and found P1698.  Started a new thread in MJ tech are called: " 98' Dash Lost Guages, Radio, Heater Controls.." for more details...

 

Still can't figure out how to make the title on a new topic appear bold!  haha... No but really..how do you do it? :dunno:

[GHayduke]

No Guages issue Resolved - interchangable plugs found !

Update- I resolved the no guages, the interior lights, and the rear signal bulb 'on' issue.  After much testing of the computer BUS lines and getting changing inconsistant readings a friend pulled the fuse box to test it & then reviewed all the connectors in the service manual as he coundn't figure out how the signal got to the fuse box, and then on to the dome light circuit board.

 

We both thought that the plugs were all unique and you couldn't plug them in wrong at the fuse box but this is not true on the 98'!

The below two top plugs will interchange.

 

 

One goes into the fuse box and the other goes into a wiring plug.  I colored one green (in sharpie marker) and the others red in case I unplug them again.  One (green) goes into the fuse box at the bottom below the two relays.  The other (red) goes together to the right or towards the rear side of the fuse box!

 

 

Hopefully documenting this will save the next guy some trouble as my whole interior is out again... At least I know ALL my grounds are more than good now!  The front turn signals are not yet working but I'm back on track!!! :banana: :rock on:

 

So stoked to get the jeep going soon.  . :MJ 1: .

[GHayduke]

In between working on the electrical, I got some other stuff accomplished:  The exaust is complete.  The tailpipe ended up touching the extended shackles so I sliced it by the shackle and bent it out a little. 

The fender flair is on the new fender, and the fender inners tucked in. I installed the front bumper and 95' vacuum canister, & installed the two aftermarket horns from the old build, i now have 4 horns at the ready.

I had to pull the passenger side door switch out a little (they slide in housing) to get that door switch working.

[Alexia]

I HATE THAT PLUG!  While mine only had one, since it was missing features, it still kept messing with me looking at the pin out diagrams.

[GHayduke]

Wiring Questions time:  

I'm trying to get the front turn signals wired up next.  This sounded easy till I tried hooking up the front signals and they don't work.  The outer two wire bulb on one side seems to stop working.  Anyone got any advice on this?  Keep in mind I have the 98' wiring and the 88' nose & plugs.

 

I also need to figure out how to add a relay and power my 01' XJ heated seats.

 

When I do the rear wiring can I just spice in a regular 4 wire trailer connector, or will this cause issues?

[Akula69]

Front turn signals:

     We did not have a problem with these, the harness for the front cap was plug-and-play for us. In the past, problems with turn signals on the older nose caps are most commonly associated with corrosion on where the harness plugs in, bad bulb sockets, or bad grounds. If you have spliced in a plug, I would check those splices and wire codes for correctness, then I would clean the plug(s), then check for current at the contacts in the socket when the bulb is supposed to be lit.

 

Heated seats:

     We did not have that option, but the plugs for it should be on the cross body harness (included in the seatbelt warning wiring and the electric seat wiring. I do not know where the fuses for them would be...a good look at the wiring diagram would help.

 

Rear Trailer harness:

     How you hook this up depends on how you wired the rear lights. The color codes for the wires are different - again, you'd have to look at the wiring diagram to determine.

[GHayduke]

  :???:   Factory wiring harness / fusebox & options question:

 

Ok so I'm adding power & heated seats that the donor 98 XJ did not have.  If the factory harness does have the plug in points, what about the fusebox?  Will the wiring go to the fusebox & are the terminals intalled for the relay & fuse if the XJ didn't come with these options?  The direct question might be: are there build specific fuseboxes or are they all the same?

 

I'll look tomorrow night for harness plugs & terminals in the fusebox for the heated seat relay...... If anyone can offer more info I'd like to know before I spend time troubleshooting!!!

 

It never occured to me, but I now wish I'd grabbed the fusebox out of the jeep the heated seat were in... but it was a 2001 XJ Limmited I believe.

[Akula69]

All the fuse boxes are constructed the same from 97 to 01 on the XJ, but some of the wires are swapped around (and therefore the fuse locations). The only reliable source for a diagram of the P/S kick panel fuse box I have found has been in the owner's manual for the year in question. There are bunches of examples on the internet - and they all look the same - but be sure it's for your year!

I ended up buying a 99 owner's manual from Fleabay.

 

As far as the heated seats go, if your donor did not come with them installed, then it probably didn't have the controls for them either. You might want to research how the switch interconnects as well

[GHayduke]

Thanks,  it looks like the relay & controller are in the heated seats so i just need a 10 amp fuse & 25 amp circuit breaker for the two power wires. 

 

I tried wiring the turn signals again.  They are load dependant and adding extra bulbs got one side working in the front.  I'll look for a towing non-load dependent flasher unit.  The back lights I have not figured out?  I wired them as seen on other threads but they only work if the running lights are off.  turning on the parking lights cancels out the flasher? 

 

Do I wire the XJ harness from where the bulbs are instead, and if so, what wires are used (colors) and not used on the rear sockets?

[GHayduke]

I ordered the new flasher unit & I wired the back lights & they now work.. but blink fast (per the old flasher).  I'm now wondering how much of my test issues might have been the old flasher unit (just being old/original).  I feel like getting the turn signals to work has been one of the frustrating and time consuming parts of the whole build... which seems sad... so much testing and retesting with varying results.  Much of this is because it's keeping me from driving the jeep. :fs1:    Once everything works I intend to do a write up (how I did it) as I couldn't find clear accuarate info on the site anywhere. 

 

I ended up replacing the dying Reverse light sockets with sockets for 1157 bulbs, so I wired the reverse lights to use both filaments! :brows:  This way the rear uses all the same bulbs (1157) which is nice because I buy commercial packs (10 bulbs to a pack) cheap.

 

I got a new front lighting harness in the boneyard Saturday so I can just change out the plugs and lights,  It was working with the old stuff (combo of both harnesses), but will be much cleaner with a factory harness. 

 

I also did the Headlight conversion this weekend.  The factory wires now trigger two 20 amp relays (one for low & one for high) then power will feed through 10 guage wire to the new halogen conversion 200mm headlights (Using replaceable H4, 12V street legal 55/60 watt bulbs (for now)) Hopefully these will be noticeablly brighter.  I also got a boneyard XJ switch panel with a fog light switch & wiring so I can later add additional driving lights and have them look factory.

 

I wired in the curcuit breaker & fuse for the seats but haven't installed the seats yet.  I'll work on the interior as time allows this week & hopfully when the flasher arrives I'll be driving the Jeep... I think I'll skip the rear interior until I get a few weeks of driving in & work out any bugs.  Then I'll get carpet & finish out the inside.

Carpet is sounding good as were already starting to flirt with freezing weather here north of Chicago...

[GHayduke]

I put the center consol and dash back together less the panel under the steering wheel.... Looks like the flasher may not arrive until Halloween even though I ordered it on Saturday & requested priority 2 day....

[GHayduke]

Quick update.... I got the turn signals working!   :thumbsup:  WooHoo!! After realizing I was getting intermittant/varying results I ordered the Multi-Function Switch and Tridon towing flasher,  before I get the switch, I first tried a LED non-load dependant flasher but it did not resolve the problem....

 

I took Friday off to work on the Jeep.  I replaced the Switch and Flasher unit to rule those out as a issue.  I then replaced a couple sockets that looked questionable (corrosion/rust) with new ones.  Then I started with the rear light that was not working. 

 

I decided to act as if I didn't know what wire was 'supposed' to do what on the sockets (based on labeling & wire colors) and started over.  I turned on the parking lights and checked each socket to determine what wire was the dim / parking lamp side & wired them in.  Then connected the high or 'major' wires (turn/brake)  I checked every socket & found a couple sockets wired wrong front and rear.... (I guess working on them late into the nights was not a good idea!!  :doh:  ). Once checking everything I got both sides working with either new flasher unit, but the factory one Is bad.... I'll be adding a trailer harness so I'm running the towing one for now.

All the connections are soldered and taped up and ready to go.  I never thought I could get so exited about seeing turn signals turn on and work! 

 

I finished putting the dask and front end together and tested to confirm everything still workes. 

[GHayduke]

Some Rear XJ to MJ lighting details:

 

The final wire harnesses (with the socket plugs on them) to each XJ tail light were the same so not a great place to referance the colors.  I referenced the colors on the XJ interior harnesses that goes back the the rear, or in a MJ conversion where they go through the floor.  I made one harness to the rear & only ended up using one wire (right turn) from the passenger side harness as wiring is redundant.  Below the first color is the main / second is the stripe.  The colors on my 98’ XJ harness were as follows:

 

Brown = Parking lamps/running lights

Green w/red = Left turn signal

Brown w/red = Right turn signal (from passenger side harness)

White w/red= Brake

Brown w/ light green = Reverse

 

I made a new wire harness by using some heavy bonded 4 wire trailer harness wire & added two more wires to it.  I then connected the turn/parking/brake wires to match trailer wiring colors & made reverse & ground black and red.  On the rear factory lights you may need to cut one of the wires that joins the two lights that’s not for the parking lamps. I chose to make the top lamp brakes/ parking, middle Turn signals/running, bottom reverse with two elements (1157 bulb). Some photos below (rear bulbs tied together, new harness wire, notes, left tail wiring while troublshooting).

 

 

When soldering in the wiring I also added a short tail of trailer wiring that will be used in the future to connect to the trailer lighting converter minimizing hacking into the wiring so much later.

[GHayduke]

Front Axle seals are replaced!

 

Pulled the axle shafts and unit bearings as one big chunk & set them aside.  Used a 3/4 inch metal rod to knock out the old seals and push rags & paper towels through the housing using parts cleaner in between to clean the junk out of the axle tubes. Pulled the carrier as a unit.  Bought a 36" long, half inch ratchet extention and feed it in from the outside & put a 36mm socket on it that fit the seals really well & had a friend tap in the new seals as I lined them up inside the diff.  Reassembled and no more leaks!  

 

I overfilled the diff some, not sure if thats bad on a D30 axle?

 

While apart I rented a spring compressor and added some factory rubber spring isolators below my lift spacers.  Now I have a little over 2 inches of lift up front (not counting new factory isolators) and a little less forward rake overall.  I still need to go flex the suspension & drive it some to see if anything settles or adjusts to see what I'm left with.  I'll take pictures when it leaves the garage.

 

Next I need to align the hood, re-mount the headlight relays as the hood prop rod hits them, and bolt in and wire the seats.  Then I can go for my first test drive and flush the cooling system (it currently has water & cleaner in it). 

 

Can't wait to drive it, but I think the steering may need adjustment before being driven daily....  . :MJ 1: .

[GHayduke]

It was a dark and stormy night.....

 

Last night I put in seats, adjusted the hood, & buttoned up the electrical and pulled the jeep out into the driveway under it's own power! Ran it for awhile while I washed off some dust/grease/drill shavings etc. I was waiting to see hot hot it got as it only have water and coolant flush/cleaner in it. It seemed to not overheat.

 

It was a rainy nasty night, without the wife home or freinds around for support, so I decided to go out for the test drive anyway!  . :MJ 1: .  :banana:    Ran well and the steering is only slightly off so the turn signals don't cancel right.

 

After a couple miles around town, I came home and fushed the cooling system and put in new antifreeze. When I put the front end together I thought the radiator drain was in a akward spot, but after doing a JK Wrangler this weekend- it's comparablly in a easy to reach location!

 

I need to seal up some leaks as water got in from washing it, but for the most part it's running great! I'll take some pictures when I get it out in daylight... :rock on:

[GHayduke]

Drove the Comanche yesterday & put 55 miles of mainly non-highway on it with no major issues!  :banana:   Rides pretty nice too.

 

I did find out the heater is stuck on hot, and after troubleshooting, it appears the hot/cold blend door is stuck.  Looks like I'll have to pull the heater box which means pulling the dash again......  At least I should know by now how everything goes together!