Oops, what did I do now...

[wooky48]

I was not thinking and closed the hood without putting this plastic cover over the battery :eek: :mad: (battery is a wee bit taller than it should be), after opening the hood back up I tried to start it up, spun over but I don't hear the fuel pump charging the lines. Is there a pump relay I might have burnt up? I don't have a wiring diagram and don't know where to start looking (nothing on the fuse panel says "pump"). Does anyone have a diagram so I can trace this blunder of mine?

[HOrnbrod]

I was not thinking and closed the hood without putting this plastic cover over the battery :eek: :mad: (battery is a wee bit taller than it should be), after opening the hood back up I tried to start it up, spun over but I don't hear the fuel pump charging the lines. Is there a pump relay I might have burnt up? I don't have a wiring diagram and don't know where to start looking (nothing on the fuse panel says "pump"). Does anyone have a diagram so I can trace this blunder of mine?

 

Are you saying that if you don't have this plastic cover thingy over the battery, the hood will contact the + terminal of the battery?? Good Gawd, I hope you're not saying that....... :huh???:

[wooky48]

I was not thinking and closed the hood without putting this plastic cover over the battery :eek: :mad: (battery is a wee bit taller than it should be), after opening the hood back up I tried to start it up, spun over but I don't hear the fuel pump charging the lines. Is there a pump relay I might have burnt up? I don't have a wiring diagram and don't know where to start looking (nothing on the fuse panel says "pump"). Does anyone have a diagram so I can trace this blunder of mine?

 

Are you saying that if you don't have this plastic cover thingy over the battery, the hood will contact the + terminal of the battery?? Good Gawd, I hope you're not saying that....... :huh???:

 

Uh, yup, thats what I'm saying and that is IF the battery is sitting toward the passenger side of the tray, I just wasn't thinking this time :nuts: when I closed the hood, gonna get the right sized battery tomorrow. I'm just hoping that I didn't fry anything major (only down about 15 seconds and ignition, lights, etc was off), I opened the hood right back up and didn't see anything burnt or still smoking except the point where contact was made with the hood.

[HOrnbrod]

Uh, yup, thats what I'm saying and that is IF the battery is sitting toward the passenger side of the tray, I just wasn't thinking this time :nuts: when I closed the hood, gonna get the right sized battery tomorrow. I'm just hoping that I didn't fry anything major (only down about 15 seconds and ignition, lights, etc was off), I opened the hood right back up and didn't see anything burnt or still smoking except the point where contact was made with the hood.

 

It only takes a millesecond or so to fry things when you apply a dead short to the battery. You most likely took out your fusible link in the + battery cable. I believe the Renix fuel pump is also on a fusible link. First thing is to replace the vattery then go from there. This link should help on the fusible link repair. Hopefully the Renix guys will chime in as to their exact locations. :cheers:

 

http://www.autozone.com/az/cds/en_us/0900823d/80/15/3e/6c/0900823d80153e6c/repairInfoPages.htm

[mvusse]

I'm not so sure about that. If there is a dead short from the battery post to the hood, no current will be flowing through the battery cable, and the fusible links should be fine.

[wooky48]

Thanks hornbrod, I was about to head out and start looking for what damage I did. Yesterday I did notice that instead of the usual pump noise the was a barely audible high pitched "whine" that lasted about the same length of time as the pump noise. Chaulk this up as a learning experience or just a brain cramp :oops:

[HOrnbrod]

I'm not so sure about that. If there is a dead short from the battery post to the hood, no current will be flowing through the battery cable, and the fusible links should be fine.

 

You're probably right, but there was current flow to ground, a lot of it, and it could backfeed in weird ways, like to the computer, etc. Hopefully it just scorched the hood and nothing blew.

[wooky48]

An update on my blunder..... I fixed some wiring issues at the battery, no go, still have starter operation and key buzzer, lost everything else :eek: no lights, 4 ways, anything. That high pitched whine (it's almost like a new type buzzer with extremely low voltage to it) is still there under the dash, barely can hear it but it whines when I turn on the light switch and does it momentarily when I turn the ignition on. I now have a wiring diagram, thanks fiatslug, gonna study on this some more I HOPE it isn't the engine computer).

 

Now for the 64 dollar question, is there a way to tell if the fuse link is bad, there are two of them (green) connected to the battery post on the starter solenoid that go to red wires (just like the diagram shows) that feed everything on the truck except for the starter.

 

Man do I feel stupid with this happening :mad: :rant: :wall:

[HOrnbrod]

A fusible link is just that; when it fries it opens up continuity-wise. You need a meter on the ohms scale to check continuity or a test light as a minimum.

[JeepcoMJ]

whining under dash sounds like perhaps a engine computer issue.

[mvusse]

Usually when a fusible link blows, it burns the insulation off as well, and all you have left are two halves not connected any more. I had a short in the tail light wiring on my F100 once (don't ask me how, too embarrassing), and it made the headlight switch whine when I turned the lights on. Only I had lights for a few seconds until the breaker tripped, and the buzzing disappeared, and like a minute later the breaker would reset and the whine would be back, along with the lights, for a few seconds anyway.

 

Still do not know why the headlight switch would whine, as it is a DC system, and no electronics besides the radio (1974 engine).

 

I would turn on the ignition (but not start the truck), turn on the lights, and see if you can locate the actual source of the whine.

 

Wiring diagrams are useful, but if there's a noise to track down, that is usually a much faster way to find the problem.

[FxRacing282]

to check a fuseable link you pull both the side and if it stretches then its no good. if it feels like a regular wire then your all set. if you can't tell the difference then get a test light to ground and to the end of the fuseable link from the battery. its that easy no ohm meter or none of that for this. if the lights lights up then its good, if it doesn't then its no good. if its halfway lit then replace the connectors on the battery and the fuseable like as 20 years or so will corrode the insulator and wire away.

possible the whine is the blower motor?

[HOrnbrod]

to check a fuseable link you pull both the side and if it stretches then its no good. if it feels like a regular wire then your all set. if you can't tell the difference then get a test light to ground and to the end of the fuseable link from the battery. its that easy no ohm meter or none of that for this. if the lights lights up then its good, if it doesn't then its no good. if its halfway lit then replace the connectors on the battery and the fuseable like as 20 years or so will corrode the insulator and wire away. possible the whine is the blower motor?

 

Highly scientific. Use a multimeter to be sure.

[wooky48]

Thanks for all the replies, I've always been better at wrenching :wrench: than electrical, never messed with fusibles cause never had one go bad. Funny thing is that in the Army I worked on commo rigs but knew where everything was from school :nuts: In a learning curve here I suppose Tomorrow after work I'll dig under the dash and find the source of the noise I'm hearing (I don't think it's the blower because it is turned off but it does work) I'll do a search but the ECM is above the gas pedal under the dash?

Anyway, thanks again for the pointers and tips yall :bowdown: Once I finger out where everything is.............

Oh, and the fusibles here feel kinda rubbery, not like a good wire.

[FxRacing282]

yeah what you can do is replace the fuseable links with regular wire that is the same guage and but in a regular fuse like in your fuse block. some people don't like doing that but it is a zillion times easier to check them and even easier to fix it. yeah so grab a test lights and follow the wire to its connector and see if the light will light up.

[wooky48]

yeah what you can do is replace the fuseable links with regular wire that is the same guage and but in a regular fuse like in your fuse block.

I had thought of that, using a separate blade type fuse block, but the next question would be what size (amp) fuse to put in the circuit, 18 gauge fuse link X 4 (12 gauge on the alternator). I did find out that the ecm is where the whine was coming from, fried, the mechanic at work said his brother did basically the same thing and the same result (no lights etc) and was the ecm. I got it out and will look for another at the junk yard one day this week. An expensive lesson in being more careful before closing the hood from now on :oops:

Just in case, is there more than one number that would work with the 2.5 ? The numbers on mine are "EF 89 53004763" on a paper label and

"S100801104A

Made in France

8839" on a foil type label

[BLHTAZ]

53004763 is the part number. It supercedes to JR004763, but neither number is available any more through the dealership as I just checked them both and ran a nation wide locator as well to see if any dealerships or warehouses had one left, but no luck.

[wooky48]

53004763 is the part number. It supercedes to JR004763, but neither number is available any more through the dealership as I just checked them both and ran a nation wide locator as well to see if any dealerships or warehouses had one left, but no luck.

I was afraid someone would say that, I checked at one salvage yard, no luck (they have mostly 6 cylinder Cherokees) The search continues.......

[JOMJ87]

I may have one laying around from a 87 2.5 TBI MJ. Not sure your exact specs but i think I hav eit from my motor swap. It worked fine then and should now. I have softball tonight so i will check when i get home from that and PM you the details on it and see if it will work.

 

Cole

[wooky48]

I may have one laying around from a 87 2.5 TBI MJ. Not sure your exact specs but i think I hav eit from my motor swap. It worked fine then and should now. I have softball tonight so i will check when i get home from that and PM you the details on it and see if it will work.

 

Cole

Thanks Cole , I've got a line on one maybe but a spare one can't hurt since a 4 seems to be a rare breed.

[mvusse]

A local yard has a Manche with a 2.5. It's buried in a corner, so I doubt it's going to go anywhere soon, I need to get back there to get the seat brackets off, I'll try to remember to check if you still need the ECM by then.

[brigarpeon]

Fuel pump and key buzzer work from the latch key system. There are 2 blue relays on your passenger side fenderwell, one is the fuel pump relay the other is the Latch key relay. Replace both and see what happens. Even if the ECM is bad you shoud still get the fuel pump and latch key relays to kick in. It still will have fuel, air and spark with a bad ECM, it just won't start because it does get the spark at the right time.

 

At the starter relay:

green wire with green fusible link= ignition

red wire with orange fusible link= latch key

red wire with orange or green fusible link= fuel pump

[mjeff87]

as a third backup for you.....I'll be starting a 4.0 swap on my 2.5 MJ here within a couple of weeks. Once I pull the 2.5 wiring harness and replace with the 4.0, I'll have a spare 2.5 ECU. If you need it, let me know.

 

Jeff

[wooky48]

brigarpeon, knowing that I have the key buzzer, can the relays be swapped for test purposes or are they not the same ? The brain is presently out and my Dad picked up the one I called about earlier today (it was on the west side of Atlanta where he lives, I'm on the east side).

as a third backup for you.....I'll be starting a 4.0 swap on my 2.5 MJ here within a couple of weeks. Once I pull the 2.5 wiring harness and replace with the 4.0, I'll have a spare 2.5 ECU. If you need it, let me know.

 

Jeff

And here I thought I was gonna have a hard time finding another one ;) , you guys are great, 2 and possibly 3 additional brains offered in just a few hours :bowdown: Hey Jeff, if the harness isn't butchered (like mine is, somewhat) that would be a nice bonus, we'll talk when you have it out.

[brigarpeon]

Yes they can be swapped out. They are a standard relay you can pick up at your local FLAPS. Just take it in with you.

 

Friend of mine had a Ranger, very similar harness, latch key, fuel pump system. That lost the computer. Picked up a parts Ranger for $25 that ran, changed the ECM ran great til one day the map sensor went bad. We worked at it for a month changing out all the electronics from the parts Ranger. Finally I said I thought it was the ECM again, he said "no way" because it had spark, fuel and was plainly getting air. I said ECM. It sat for 10 months, one day he said he wanted to get it running. We were re-checking what we had done before. Then he tells me about his buddy who came over and jumper wired the latch key over at the harness. Once I looked at it I could still see the arc on the terminals, He didn't tell me that 10 months before and assumed that because he had spark and fuel they didn't hurt anything. Again I said ECM. He went over to his uncle, who gave him an ECM, put it in and the truck fired right up.