There is a ton. The main ones are the two ground points from the engine, and the negative of the battery. For the rest, every single light can possibly have individuals or combined ground points. As long as they're connected to the frame, there is your ground. If you need one, you can drill your own with a self tapping screw, as long as you don't damage anything hidding where you drill. What's the problem you're trying to resolve?

 

Thanks for the reply Reptile;

I'm trying to get a grasp on the grounds ahead of time.I know something will go wrong and I want to be ready. I appreciate the help.

My right side dash indicator is stuck on when I turn my lights on (headlights and running lights). When I put on my right blinker, go out and check it, it is very very dim. But there is minimal power getting to it. Basically it looks like I'm making a left turn all the time because of my dead right side. Changed bulbs, checked fuse, housing is all good and socket wiring seems to be in tact. I'm lost on this one.

Thanks!

 

I've got the factory wiring manual with a Ground Distribution page in it.

There are 2 points on the left inner fender.

There is the engine dipstick tube stud. SUPER IMPORTANT!!

There is the ground to the lower diagonal dash brace to the left of the steering column.

There is one in behind the trim panel where the spare tire mounts.

The one on the instrument panel brace grounds a ton of things. Probably too many things as a matter of fact, given it's poor mounting point on the brace with a self tapping screw. I remove the screw that it's held on with, extend the wire, using the same gauge or bigger, and terminate it to the stud near the fusebox.

There are also grounds from the engine to chassis, notably the poor one from the back of the head to the firewall but that wouldn't affect your dash lights. Not that the engine to chassis grounding shouldn't be addressed. I'm working on a write-up for that in the near future.

 

I've got the factory wiring manual with a Ground Distribution page in it.

There are 2 points on the left inner fender.

There is the engine dipstick tube stud. SUPER IMPORTANT!!

There is the ground to the lower dash brace to the left of the steering column.

There is one in behind the trim panel where the spare tire mounts.

The one on the instrument panel brace grounds a ton of things. Probably too many things as a matter of fact, given it's poor moounting point on the brace with a self tapping screw. I remove the screw that it's held on with, extend the wire and terminate it to the stud near the fusebox.

There are also grounds from the engine to chassis, notably the poor one from the back of the head to the firewall but that wouldn't affect your dash lights. Not that the engine to chassis grounding shouldn't be addressed. I'm working on a write-up for that in the near future.

Wow. What a gold mine of info. Thanks Cruiser.

 

Just improve the ground wire for the instrument panel like I described above and see if your voltmeter reads higher .

 

Very cool, thanks Cruiser.

Thanks to the both of you. Works out well because I get Voltmeter's at cost through my work, so I think I know what my Monday purchase is going to be.

Great list too Cruiser, will be a big help down the road I'm sure.

Here goes nothing!

 

I added some things to my original post. The ground wire for the instrument panel is located on a DIAGONAL brace under the driver's side dash.

Always use the same gauge wire or a size larger when extending the ground to reach the stud in the kick panel near the fusebox.

 

Thanks guys, I definitely got the expertise I needed.

This is a bit of an ironic question seeing that I work in an electrical wholesaler, but when replacing the block-firewall ground strip, would you know what guage wire I can replace it with? Right now it is the stock braided wire and is starting to show its age, I have heard you can go with a #2 or #4 wire as a replacement. I know going bigger is ok, but obviously I don't want to risk going smaller.

Thanks for the help guys, many a headache saved :thumbsup:

 

There is a part for that, altough 4 AWG wire should work fine, just make sure the insulation doesn't touch the engine...

O'Reilly part #CA756

 

No problem.

 

#4 will be fine and don't bother putting it back to the head bolt/stud. Just run it to the intake manifold to a heat shield bolt. Be absolutely sure to scrape the paint off the firewall at the mounting point.

 

Not sure about the 88, but the early 90s XJ have a black rectangular front lighting harness connector behind the left headlamp under the airbox that is prone to corrosion...check it out. Also, make sure all the front and side lamp sockets are absolutely clean and dry. Make sure the replacement lamps you installed are the EXACT replacements as specified in the owners manual. Trouble in any of these areas can cause the symptoms you describe. Note: this is not to say that you don't have a ground problem...check them out also as you have been advised. Good luck with your troubleshooting.

 

No need to remove anything except your hat. LOL. It's a black, round diagonal brace to the left of the stering column.

Since you'vew developed an interest in grounds, how about adding a #4 cable from the firewall on the driver side where that crappy braided cable attadhes and run it over to the intake manifold? Clean the firewall attaching point to bare metal while you're at it.

 

Since you'vew developed an interest in grounds, how about adding a #4 cable from the firewall on the driver side where that crappy braided cable attadhes and run it over to the intake manifold? Clean the firewall attaching point to bare metal while you're at it.

I knew the brim of my hat was getting in the way of something

I am going to swap out the braided cable, it had it's day, but oil is winning the battle with that one. I'll be swapping that out on the weekend, and hopefully get a better look at that brace while I'm at it.

Thanks Cruiser.

 

Just run it from the firewall to the intake manifold. No sense screwing around with it on the back of the head.

 

Do you think that would be easier?
I was going to do a straight swap with new connectors/wire on the existing ground points. They aren't corroded and thought it might be quicker using the established spots.

Where exactly on the intake manifold would you put it, and would it make any difference performance wise to move the contact points?

 

I go to the rearmost fuel rail bolt. Works as well as the rear of the head and doesn't get oily like the rear of the head. Plus, you can get a cable from the parts store with a 3/8" lug at each end easily. If you use the headbolt, you need one with 1/2" lug on one end.

 

Ok, on to attempt #837

I found the dash brace ground, finally. Turns out the brim of my hat was what was blocking my view. That and a bunch of chaotically bound wires

:thumbsup:.

So that ground is all good, and I went through my instrument panel and there is no issues there, inner panel grounds are good (could only find one). But still a stuck indicator, etc... Minus having used a voltmeter yet, does this sound like it's an issue with the power at this point, not a ground?

Appreciate all the help. If you're ever in Vancouver, let me know. I owe some people some beer.

:cheers2:

 

Actually it's above the dash brace on an unpainted metal part of the dash panel. I researched this yesterday since alot of people have asked about it. attached is my first drat of a write-up on how to improve the instrument panel ground.

Improving the Instrument Panel Ground

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16” head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.

Make up a jumper wire with #10 gauge wire about 10” long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8” round wire terminal.

Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point.

Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.

**Special note for Comanche owners: Make your jumper wire 12” long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

 

I don't know if this is a tell or not, but when my hazards are on (no other lights on) the rear blink in sync, but the front blink out of sync.

Moved the dash ground, still same issue

Going to be trying the voltmeter in the next couple days here, hopefully.

 

Front blinker sockets could be corroded or a bulb isn't seated properly. The blinkers ground on the driver's side inner fender under a tapping screw.

 

So I have gone through and adjusted all the ground points to where they are solid and clean. Cleaned the lamp housing. Still no change.

My next shot at this is going to be to start at the lamp and work my way back through the line and make sure the wires are good along with the harness, etc...

Any suggestions on the best way to go about this, or just open it up and follow the line?
The wire covering is old and snapping so I was going to take the front end off and clean/redo what needs replacement.

Sound like a good route to go?

 

There's a plug on the driver side inner fender kinda under the air filter housing. I'd check that next.

 

See my post (#15)...this connector can be a corroded mess.

 

Why do I feel like I just got scolded by my Mom


It's more like Dad than Mom.

 

Thanks Dad

 

You're welcome Grasshopper. What show is that from?

 

I'm a bit young to remember the original, but I think it was Kung-Fu with David Carradine?

 

Good answer!!!

 

Alright! And I didn't even have to use Google. It's nice when my memory works :thumbsup:

 

So this morning I got up to go to the grocery store, get in the Jeep and turn on the headlights. Dash indicator is off. Take a look at the front park lamp and I see the light! Not very bright, but something (yesterday after all the cleanng I had done I all of a sudden had no light in there).But now I'm more confused than ever. How does it just power up like that?

Anyway, still going to try out those connectors this weekend and see how it goes.

 

I thought I had already posted these in this thread, but I guess not.

Improving the Instrument Panel Ground

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver's side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.

Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.

Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.

Look above the driver's side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.

**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver's side kick panel close to the fusebox on the 8mm stud.**

Revised 11-29-2011 Renix Ground Refreshing

The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.

The components grounding at the dipstick tube stud are:

Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.

The factory was aware of the issues with this ground point and addressed it by suggesting the following:

Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud's mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.

Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn't hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.

While you're in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.

Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver's side of the firewall. This cable is undersized for it's intended use and subject to corrosion and poor connections at each end.

First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3'4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.

A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.

A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.

If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.

Revised 11-28-2011

 

I thought I had already posted these in this thread, but I guess not.

Improving the Instrument Panel Ground

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver's side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼" or 5/16" head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.

Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.

Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.

Look above the driver's side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.

Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver's side kick panel close to the fusebox on the 8mm stud.

Revised 11-29-2011 Renix Ground Refreshing

The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.

The components grounding at the dipstick tube stud are:

Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.

The factory was aware of the issues with this ground point and addressed it by suggesting the following:

Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud's mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.

Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn't hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.

While you're in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.

Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver's side of the firewall. This cable is undersized for it's intended use and subject to corrosion and poor connections at each end.

First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3'4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.

A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.

A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.

If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.

Revised 11-28-2011

What about the WJ? Didn't see anything like this.

 

^^^ You did post that already, sorry didn't mean to come across like I'm not paying attention to the posts. I actually have them printed off and in my glove compartment for quick reference. Just wasn't sure if the sudden power there was a clue. I'll see what happens when I go through the harness shortly.

Thanks Cruiser.