availtech

Hey, All

I have the MOPAR service manual for the JK and found it's missing some information, namely the locations of some of the engine bay grounding points. I thought I'd post this with all the locations identified for easy reference:


G100


G101 and G104 - These can be found under the heat shield near the catalytic converter on the right side (passenger for US folks) of the motor







G102 - This one is missing from the service manual. It's located just to the left of the right side (passenger) headlamp assembly, near the power steering reservoir:



G103 and G105 - Right (passenger) side of the engine bay




Hope this helps!

OscarMlke

@availtech

Thanks for taking the time to do this.

Joe C

Good info, thanks for posting. Do you know of good grounding locations behind the glove box? I want to ground my CB radio directly rather than routing extra wires into the engine bay.

availtech

Yep! Location G201 and G203, They are under the kick panel in the passenger footwell.

karls10jk

Thank you for posting these diagrams, they're helpful for folks who wouldn't otherwise have access to that info.

schles

I could use some help from the brain trust. New Member. 2014 JK Wrangler Sport, Manual Transmission, 123k miles. Short story (if you want long story see below) after replacing head gaskets, oil cooler, heater core, new spark plugs, new PCV, jeep won't start. Starter sounded like it was freewheeling, replaced starter... still won't start. After I got it all back together on first start attempt engine coughed for a second or two and now nothing since. Tried jumping battery...no difference. Looked over fuses and relays in TIPM...doesn't look like anything is blown. I can rotate harmonic balancer by hand with socket so it doesn't feel like engine seized. Engine was running before I took everything apart. Engine was apart in garage for 4 months (life and work got in the way of maintenance). When I got everything back together there is one ground coming off negative battery terminal wire bundle that I could not find original location for. See picture below. I've tried grounding to firewall and engine block but neither makes a difference. Tried hours of searching for OE ground locations found this thread https://www.jk-forum.com/forums/stoc...cations-355618 and I think it's either G101 or G104.

Long story, loaned jeep to 17 year old son for daily driver. Jeep had small oil leak from oil cooler, no big deal check oil once a week add half quart every month or so got new cooler waited on good chance to install. Showed son how to check oil, how to fill, how to change oil basic car maintenance stuff that anyone should know. One day son called from down the road that jeep was "overheating and leaking brown fluid from under engine". I told son to shut down and wait for me. When we got jeep towed back to house looked like chocolate milkshake leaking from engine. Turns out son put 3 more quarts of oil in without even checking dipstick. So I slapped my forehead and started my teardown / rebuild project. Drained oil and thankfully it was clean (no water coolant in oil). However there was aerated / foamed oil mixed with coolant in EVERY part of the coolant system, radiator, heater core, engine block, oil cooler, etc. I can post pictures if anyone is interested, it was ugly. Don't let your teenagers over service oil in your car. Head gaskets were intact so my theory is that the extra oil got churned up by crankshaft and over pressurized oil system, blew past already leaking oil cooler and forced it's way in to coolant system / block / etc.

mcvincent

@availtech , thank you for posting those ground locations. Is yours a 3.8 liter? I've got a 2013 JK with a 3.6. I was able to find G100, G102, G103, and G105 using your diagrams and photos. However, on my Rubicon, I did not find G101/104 together under the heat shield. Instead, I had to pull the passenger side wheel well cover and then a single ground is on the block. Additionally, I have an additional engine compartment ground on the driver's side by the washer reservoir. Photos below.

Block ground, passenger side, remove liner.

Ground, driver's side, behind washer reservoir
Just uploaded in the hopes it helps someone track down an erratic electrical problem.

webhannet

On my 2008 jku, I started to have trouble last year. The AC wouldn't work. The remote start didn't work. And some other things. It turned out all of these things were not working because of one ground at the back of the engine. In addition to the problems I was having, I also had a check engine light due to an O2 sensor and others. The garage tried tracking everything back from the various things that weren't working comma and they all went toward one grounding point on the back of the engine. It was easier for them to run new grounds to the items not working comma so that was done. Afterward, everything was working properly. Later, I had more problems of the same type. Again comma a makeshift ground was made, and things have been fine for months. I'm a bit angry because the first garage which I have used for years recharged the AC and did other expensive things before they figured out the problem. I have no idea how much this added. Even worse comma I had no AC all summer. Good luck to everyone

ronjenx

I, too, have fixed several problems by routing new ground wires and cleaning ground points. The best one saved me a few hundred dollars. I got an ABS code whose only fix in the troubleshooting chart was to replace the ABS module. Based on previous experience with other things that quit working, I looked for a bad ground. Cleaned up the ground point, and it's been good ever since.

fpgus07jk

I had one of the ground studs on the body in the engine bay break off during a repair (similar to the location you have circled above). Is it okay to use a self tapping screw and make a new ground next to the broken stud, and if so, is there a specific combo of washers that I should use to build up the ground stack? (First electrical repair I've had to do; conquered the spider gears thanks to @karls10jk and @resharp001 a few years back...hoping the forum can help here as well. Pic attached for reference....