Weird symptoms ... related?

[bigalpha]

88, Auto, I6

 

Breakdown of symptoms:

- Left blinker does not work at all.

- Right blinker works w/ lights off.

- R. blinker blinks at half speed with lights on.

- With lights on, the R. blinker indicator stays lit on the dash but the bulb itself does not light up.

- Fuses good

- New bulbs -- the ones that were recommended are dual filament. If only used for blinking, why do they need two filaments?

 

Other symptoms:

- High idle, truck will accelerate on flat land and the transmission with upshift through the gears.

- When shift from 'D' to 'P' or 'N', the truck idle will increase a lot. I don't have Tach, so not sure of exact RPMs.

- When it downshifts, the trans revs up for just a second then it'll downshift. It seems like it's lagging.

- Replaced IACV with new, but made the problem 10x worse. I was doing 45mph w/o using the gas w/ new IACV.

- TPS tests within specs.

- MAP/MAT test within spec.

- No discernible vacuum leaks, though some of the hoses are taped to the elbows and such.

- Had serious blow-by issues, but I cleaned out the grommet (new one on the way).

- Old IACV was caked in oil, but I cleaned it and put it back in since the new IACV made the issue 10x worse.

 

Are these symptoms related? I imagine a bad ground may be to blame for some of these issues, but I tested the grounds I could find (w/ DMM) and they tested out alright.

 

1. Where are all the grounds?

2. Do the blinkers need dual filament bulbs?

3. Why the crazy idle/shifting?

[bigd44889]

i think u have the right idea (ground or one heck of a short )

i hate eletrical good luck

did u check the ground strap from body to the block

:cheers:

[Geonovast]

The rear bulbs need to be dual filaments. Both bulbs are tail/brake/blinker. XJs run single filaments for the blinkers.

[bigalpha]

The rear bulbs need to be dual filaments. Both bulbs are tail/brake/blinker. XJs run single filaments for the blinkers.

 

What about the front blinkers? Will it make anything wonky to have dual filament?

[Geonovast]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

[vaquaro]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

:???: I think Front turn sig.s are dual filiment ( one running lite & one signal lite )at least they were in my 90 , before I removed them to mount my fogs in that location . Mounted after-market marker lites for signals behind the grill and have had the intermittant "ghost " lite on my left T. sig. dash indicator ( w/ h-lites on only )Hope you guys have a solution for this one :help:

[bigalpha]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

 

Those blinkers are only blinkers, right? The running lights are the lights that are on the corners.

 

I know some people have had some weird issues when a lightbulb shorts out and causes some funky things to happen with the circuit and things go wonky. That's why I was asking.

 

How many grounds are in the engine bay? I know there's the one that goes from battery to block, right behind the oil filter. Then, the one that goes to firewall, behind the throttle body. Where else?

[vaquaro]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

 

Those blinkers are only blinkers, right? The running lights are the lights that are on the corners.

 

I know some people have had some weird issues when a lightbulb shorts out and causes some funky things to happen with the circuit and things go wonky. That's why I was asking.

 

How many grounds are in the engine bay? I know there's the one that goes from battery to block, right behind the oil filter. Then, the one that goes to firewall, behind the throttle body. Where else?

On my MJ the signal lite (front under h/lite) was also a park/running lite , in addition to "corner" lite which has the same functions including blinker :hmm:

[bigalpha]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

 

Those blinkers are only blinkers, right? The running lights are the lights that are on the corners.

 

I know some people have had some weird issues when a lightbulb shorts out and causes some funky things to happen with the circuit and things go wonky. That's why I was asking.

 

How many grounds are in the engine bay? I know there's the one that goes from battery to block, right behind the oil filter. Then, the one that goes to firewall, behind the throttle body. Where else?

On my MJ the signal lite (front under h/lite) was also a park/running lite , in addition to "corner" lite which has the same functions including blinker :hmm:

 

What year is yours?

[vaquaro]

All 4 bulbs in front should be singles.

 

I think. I don't think having duals in there would hurt anything, though.

 

Those blinkers are only blinkers, right? The running lights are the lights that are on the corners.

 

I know some people have had some weird issues when a lightbulb shorts out and causes some funky things to happen with the circuit and things go wonky. That's why I was asking.

 

How many grounds are in the engine bay? I know there's the one that goes from battery to block, right behind the oil filter. Then, the one that goes to firewall, behind the throttle body. Where else?

On my MJ the signal lite (front under h/lite) was also a park/running lite , in addition to "corner" lite which has the same functions including blinker :hmm:

 

What year is yours?

90

[bigalpha]

I just realized today that one of the lights is out on the rear, driver side. Wonder if that can be causing any weird lighting issues?

[bigalpha]

Alright, I feel kind of like a tard.

 

I never did check the rear lights or wiring; brake, turn, running nor reverse.

 

Each tail light has 3 lights; top, middle, bottom (reverse). What lights do what? The bulbs that were in there are all 2 filament bulbs. There was some weird putty stuff in the sockets too; I had to break the bulb and pry the stem out.

 

When I turn on the headlights, the top 2 lights come on, on each side.

 

However, no blinkers from either side; headlights on or off. Not sure about the reverse lights, though.

 

There is some trailer wiring (or some tangled mess of junk) hanging out by the bumper. It's not in the best of shape. I wonder if there is something wonky going on there that's causing the electricals to be wonky too?

 

I think I took some pics of it. Looks janky so I'm not sure what the PO was doing. If the fan wiring, AC wiring are any indication, he butchered it;

[vaquaro]

:idea: Check the ground wire behind the left rear tail lite first . While your there , check all the bulbs and sockets . Might as well gather up 4 new t/l screws ,your bound to snap off a few :waving:

[bigalpha]

Left = driver or passenger side?

Is the ground wire attached to the body?

 

I managed to get all the screws out w/o snapping or breaking any of them, though one of them is stripped.

[maddzz1]

left is drivers side. Some of that wiring may be for the license plate light; couldnt tell from the pic if they were there or not.

[bigalpha]

left is drivers side. Some of that wiring may be for the license plate light; couldnt tell from the pic if they were there or not.

 

Alright, thanks; I'll give it a looksie later. Yeah, it wasn't a very good picture but I'll take some better ones. It was all covered in oil and gunk, too, so I'm sure that didn't help any.

[Pete M]

Check that ground (dr side right behind the taillight housing), and then check the trailer harness (probably should re-do it), and then check the factory connector in the rear wire harness. It's located right behind the drivers side rear tire. I has corrosion in there that once robbed me of my brake lights. It was so bad that I had to hack the whole connector out and replace it with an aftermarket one. :(

[bigalpha]

Alright, so this is what I've done:

 

Replaced all rear bulbs with new and new front blinker bulbs. The rear blinkers work sometimes; the front blinkers are the same. I could not figure out a rhyme or reason to the rear blinker issue.

 

Reverse lights work, and license plate lights work. The reverse light plug shows ~10.5V. I tested this against the ground on the driver side, and it registered the same V. If this V is too low, let me know.

 

I did not have a chance to really dig into the janky trailer wiring. It looks like hell, to be honest, and there's a lot of electrical tape. I'll need a wiring diagram for the rear end to make sure they wired the harness correctly, and so I can identify all the wires and what they're for. It's easy to get to since I do not have a tailgate. Could bad wiring in the rear cause all the blinker problems?

 

I fixed the janky wiring they had for the e-fan as well. It was tapped into a hot wire that goes to the ballast on the driver side fender. I rewired the fan correctly and the ballast correctly. I did not use e-tape; rather, I used those small wire adapters that crimp onto the wire to ensure a solid connection. Much better.

 

I also pulled out the radio and started messing with THAT janky wiring, but that's for a different thread.

[bigalpha]

Update time!!

 

After much troubleshooting and thinking and poking, I FINALLY found the problem.

 

For some strange reason, the metal tab that acts as the ground (the one that's on the side of the bulb socket) rusted completely away; though the rest of the socket is just fine.

 

What do I need to do to replace the bulb socket? It almost looks like the 3 wires slip onto a terminal and that I can just pull them off.

[Wildman]

Front or Rear socket???

 

If it's the front socket, a Ford (Help section) will fit. I don't know the item number off hand.

 

A rear socket.......you could ask for one from someone here :roll:

 

And don't forget to pack the new one with lots of dielectric grease :D

[bigalpha]

It is the front driver side. Luckily, I know someone w/ a parts rig so I'm getting a socket for dirt cheap.

 

After all this time, it took me this long to realize that tab was missing. :fs1:

[bigalpha]

Here's a long term update:

 

After testing the vacuum system, I found it was holding vacuum and there wasn't a leak.

 

Turns out the ground for the TPS (Trans. side) was FUBAR. Ran a new wire straight to batt - and it's idling pretty good. Not 100% perfect, but more like 85-90%.