Electrical issues

[DWR]

Hey guys,
I’ve exhausted a friends and my own knowledge of the TJ’s electrical system and can’t seem to find the fix. I have searched but I can’t seem to find my specific issue. I’ve checked all the fuses and relays under the hood and in the glove box, and the relay under the steering wheel (that I found out is for the blinkers).

Everything started off with an engine light, which ended up being the code for the TPS... which I unplugged, cleaned and replugged in and the code cleared after 5 or so miles (so i believe it is unrelated). After I decided to spray off the engine compartment using only normal water hose pressure, and trying to stay away from electronics. I parked the jeep in the garage and the next day surprise...

Things that don’t work:
Radio
Cluster gauges
Under hood light
Dome/footwell lights

Things that DO work:
It runs and drive as normal
Warning lights and blinker indicator on gauge cluster
Backlighting of gauge cluster
Headlights
Tail lights
Blinkers


PS... what does the one relay in the glove compartment do?

 

[DWR]

I see that there are some other cluster related issues in play right now but they do not involve the radio, under hood light, and dome/footwell lighting. My main guess at this moment would be a grounding issue but I’m unsure where to check. Any guidance will be VERY much appreciated!

 

[CodaMan]

This happens all the time to people that let their Jeep sit out in the rain. Let everything dry out in the sun for a day or so.

 

[CharlesHS]

More than likely there is a harness in the engine compartment that has water inside the connector.
Check the three connectors attached to the computer on the passenger fire wall.
With the battery disconnected... disconnect each computer harness and blowout the pins and connector.

 

[DWR]

This happens all the time to people that let their Jeep sit out in the rain. Let everything dry out in the sun for a day or so.

More than likely there is a harness in the engine compartment that has water inside the connector.
Check the three connectors attached to the computer on the passenger fire wall.
With the battery disconnected... disconnect each computer harness and blowout the pins and connector.

I did disconnect the two main plugs located on the passenger side firewall and clean/ let them dry with a fast evaporating, plastic safe cleaner spray... I don’t see a third connector though, other than the one halfway up the drivers side fender that appears to be for the headlights. If it happens often to people who let their jeep sit in the rain has anyone found where the point of water intrusion is? I’d love to at least get my radio working again.

 

[CharlesHS]

My apologies.... I missed the fact you are driving a 1997 TJ (in your profile).
The early model year TJ wiring is quite different than the 1998 and later TJs.

The link below will have wiring schematics and pin outs showing connectors, pin numbers, and wiring colors to assist in troubleshooting. I believe the electrical drawings are in section 8W.

1997 Factory Service Manual

 

[Goatman]

Agree with water in the connectors. Open them up and blow out with some compressed air. Squeeze some dielectric grease into the pin holes before you reconnect them. If you see one with lots of water use WD-40 then air then grease. Good luck. Putting a fan or a small box heater under the engine bay on the floor pointing up always helped my old CJ's dry out after washing out.

 

[DWR]

I’ll give both a shot today, thank you all! Please keep the suggestions coming as I’m trying my best to get my “COVID-19 doomsday vehicle” back 100% .... then again if it’s doomsday, who cares what speed you’re going, radio would be nice though lol.

 

[DWR]

Ok, so today is the first day that is really warm enough to let it sit in the sun and it potentially do anything here. It’s out there now but it has been in the garage the past few days chilling, nothing has changed so far.

 

[qslim]

Looking at the 4 symptoms and how they are laid out in the schematic they all have connector C108 & fuse 17 in common:

Here they feed your radio, dome & underhood lamps:

Here it looks like fuse 17 runs b+ for your IC and C108 runs the CCD twisted pair data link from the PCM:

And here the feed power to the L&R courtesy lamps

Looks like it's a blue 14 pin connector:

In the left kick panel:

Looking something like this:

That's just what I noticed after a quick glance through the manual, but I'd check that fuse and then find the connector.

 

[DWR]

Looking at the 4 symptoms and how they are laid out in the schematic they all have connector C108 & fuse 17 in common:

Here they feed your radio, dome & underhood lamps:


Here it looks like fuse 17 runs b+ for your IC and C108 runs the CCD twisted pair data link from the PCM:



And here the feed power to the L&R courtesy lamps



Looks like it's a blue 14 pin connector:


In the left kick panel:


Looking something like this:



That's just what I noticed after a quick glance through the manual, but I'd check that fuse and then find the connector.

Holy mess! Thank you! A couple questions though, are you referring to fuse 17 under the hood? If so I’ve already checked it but I’ll check again and then attempt to find that plug. I didn’t know there was one in the kick panel.

 

[DWR]

Looking at the 4 symptoms and how they are laid out in the schematic they all have connector C108 & fuse 17 in common:

Here they feed your radio, dome & underhood lamps:


Here it looks like fuse 17 runs b+ for your IC and C108 runs the CCD twisted pair data link from the PCM:



And here the feed power to the L&R courtesy lamps



Looks like it's a blue 14 pin connector:


In the left kick panel:


Looking something like this:



That's just what I noticed after a quick glance through the manual, but I'd check that fuse and then find the connector.

The fuse is good but I can’t find the plug C108 you referred to... I don’t see any plugs on either kick panel (or at least the area I know to be a kick panel) other than the obdII port? Am I missing something, or just plain looking at the wrong area?

 

[qslim]

I dunno, I never had to look for it myself. I was just going off what was available in your manual. The picture isn't great, but I'd imagine it's behind the driver side kick panel trim to the left of the pedals.. Did you pull that off?

 

[DWR]

I dunno, I never had to look for it myself. I was just going off what was available in your manual. The picture isn't great, but I'd imagine it's behind the driver side kick panel trim to the left of the pedals.. Did you pull that off?

Mine doesn’t have a cover there... is there supposed to be one? The plug in the second pic I’m 99% sure is the clutch interlock plug, which I bypassed because I like to live dangerously lol.

 

[qslim]

Hmmm. you know what, I just looked at that page again in the '97 manual (8W-90-5) and it shows it on a page titled 'engine compartment connectors - rear'. Maybe someone fat fingered it saying it is at the kick panel. The wiring diagram shows it as the first stop after C100 on the PDC, maybe it's in the engine compartment after all?

 

[DWR]

This one? If so, I’ve already unplugged it, sprayed it with connector cleaner and let it sit/dry...

 

[qslim]

Doesn't look like it. According to that pic it's a 14 pin connector that plugs into the same receptacle as two others. The manual says it's both blue and black lol.

 

[DWR]

Doesn't look like it. According to that pic it's a 14 pin connector that plugs into the same receptacle as two others. The manual says it's both blue and black lol.

Well shoot... I guess I’ll have to do some more digging then. Can’t find a blue and black connector for anything yet. Thank you greatly for the help though! I’ll report back with any news, but hopefully don’t end up with more questions.

 

[joelachr]

Try removing the panel under the steering column and looking up higher on the outside panel. I think my 2003 has 2 or 3 connectors stuffed in there.

 

[qslim]

Well shoot... I guess I’ll have to do some more digging then. Can’t find a blue and black connector for anything yet. Thank you greatly for the help though! I’ll report back with any news, but hopefully don’t end up with more questions.

No problem, I'm just typing - you're the one doing all the work lol.

Also another note I've read on here that there are some wiring differences on '97 models depending on when they were produced. I have a 99 so I never really looked into it, but I just recall seeing some folks mention it.