The WJ electronics require good/clean grounds to avoid electronic failure or create havoc. The purpose of this thread is to pinpoint ground locations along with listing which components connect to each ground. In addition to insulated ground wires the flat ground straps will also be included.
Much of this 'ground' information was gathered from the 2004 WJ FSM (Factory Service Manual). Since just knowing the ground location isn't much help I went through hundreds of pages of wiring schematics to find which components connect to each ground. And wire color-coding is included with the ground wires when found.
The photos of the specific grounds are from my 04 4.7 Limited. In addition to the 4.7 left-hand-drive WJ's the 4.0 grounds will also be included but without photos. There was just too much info to include the right-hand-drive and diesel WJ's.
This is a work in progress and corrections or additions are gladly welcomed. Also since the WJ's (1999-2004 Grand Cherokee) cover 5 years the early year WJ's may have different grounding than the later years.
Tools and supplies needed for cleaning grounds.
- Wrenches and/or sockets for removing ground bolts/nuts.
- Pliers or vice-grips in case the eyelets are seized or turn.
- Rust cutter if the bolts/nuts are difficult to loosen/seized.
- Small wire brush, fine emery cloth or fine sandpaper.
- Dremel/rotary tool with wire wheel instead of above if available.
- Spray electronic cleaner preferred some use carb/brake cleaner.
- Dielectric grease or products like ox-gard. (optional)
Tips on removing and cleaning grounds:
- Most of the eyelets are solid stainless steel where they don't have a metal coating. But if you do run into eyelets with tin/zinc coatings don't remove the eyelet coatings and just rust/corrosion.
- I did not remove body paint from under inner fender/firewall mounted grounds since the eyelets have special teeth for going through paint. Reinstall eyelets in same position as removed.
- All upper engine compartment grounds have a 10mm headed bolt or nut. Exception is the large/tall ground stud to right of plenum and all bolt/nut head sizes are included on photos.
- Note: 'left' & 'right' are indicated as if you're sitting in the driver's seat and not looking at the front. Most everybody already knows this and only mentioning when working from the front.
- My upper body/engine grounds were all fairly good/clean but I cleaned them anyhow. The grounds on the side of the engine block and underneath exhaust were fairly corroded externally due to being in the salt/rust belt.
Ground numbering:
There are approximately 13 ground locations listed and they're designated by a 'G' followed by a 3-digit number. Many flat ground straps are not even included in the ground location list but I'll try to include what has been found.
Numeric order will not always be followed in this write-up to group some area grounds together. I've typed in text for electrical components grounded on most diagrams and photos.
I realize I'm way too wordy, sorry, and most ground info can be gathered from the photos & diagrams. Component info is under the ground number/heading anyhow as well as on photos or diagrams.
Below is a chart for on ground numbers with locations. Since the exact locations are unclear additional info in blue text has been added.
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The individual grounds are below with images following the description.
G100. Near starter (4.0). No info found and a photo would help.
G100. Near intake plenum (4.7).
Conflicting info supplied by the FSM and needs verified.
For now the large/tall stud to right of the intake/plenum will be designated as G100. This insulated ground strap is connected between the large stud to the backside of the PCM case on one of the left bolts/nuts. I thought this ground was attached to firewall behind PCM but it is not and just on the back of the PCM case.
The OE number is 56038590 for this strap but not sure if available. This is the only rubber insulated half-flat ground strap found. The air box on top of the plenum needs to be removed to clean this ground good.
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Firewall ground to right/left rear coil-on-plug studs:
This flat braided metal ground strap connects to a firewall stud above PCM and goes to far back passenger side coil-on-plug stud/nut. This is a 'Y' strap eyelet on the right rear coil-on-plug stud. While one strap connects from the firewall the other strap goes over top of the transmission bell housing and connects to the rear far back driver's side coil-on-plug stud/nut. Again, air box on top of plenum needs removed to reach these far back grounds.
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G101. Right inner fender, far forward (4.0 & 4.7)
Large black 6-gauge ground cable direct from battery negative terminal. Real poor design on my 04 since I couldn't back the bolt all the way out since the head was jammed against the PDC case. I cleaned the front/back of eyelet and bolt threads with small wire brush with bolt tip still in place. I've noticed on other WJ's a hole further forward used for this ground which makes more sense since PDC wouldn't be in the way.
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![]()
Much of this 'ground' information was gathered from the 2004 WJ FSM (Factory Service Manual). Since just knowing the ground location isn't much help I went through hundreds of pages of wiring schematics to find which components connect to each ground. And wire color-coding is included with the ground wires when found.
The photos of the specific grounds are from my 04 4.7 Limited. In addition to the 4.7 left-hand-drive WJ's the 4.0 grounds will also be included but without photos. There was just too much info to include the right-hand-drive and diesel WJ's.
This is a work in progress and corrections or additions are gladly welcomed. Also since the WJ's (1999-2004 Grand Cherokee) cover 5 years the early year WJ's may have different grounding than the later years.
Tools and supplies needed for cleaning grounds.
- Wrenches and/or sockets for removing ground bolts/nuts.
- Pliers or vice-grips in case the eyelets are seized or turn.
- Rust cutter if the bolts/nuts are difficult to loosen/seized.
- Small wire brush, fine emery cloth or fine sandpaper.
- Dremel/rotary tool with wire wheel instead of above if available.
- Spray electronic cleaner preferred some use carb/brake cleaner.
- Dielectric grease or products like ox-gard. (optional)
Tips on removing and cleaning grounds:
- Most of the eyelets are solid stainless steel where they don't have a metal coating. But if you do run into eyelets with tin/zinc coatings don't remove the eyelet coatings and just rust/corrosion.
- I did not remove body paint from under inner fender/firewall mounted grounds since the eyelets have special teeth for going through paint. Reinstall eyelets in same position as removed.
- All upper engine compartment grounds have a 10mm headed bolt or nut. Exception is the large/tall ground stud to right of plenum and all bolt/nut head sizes are included on photos.
- Note: 'left' & 'right' are indicated as if you're sitting in the driver's seat and not looking at the front. Most everybody already knows this and only mentioning when working from the front.
- My upper body/engine grounds were all fairly good/clean but I cleaned them anyhow. The grounds on the side of the engine block and underneath exhaust were fairly corroded externally due to being in the salt/rust belt.
Ground numbering:
There are approximately 13 ground locations listed and they're designated by a 'G' followed by a 3-digit number. Many flat ground straps are not even included in the ground location list but I'll try to include what has been found.
Numeric order will not always be followed in this write-up to group some area grounds together. I've typed in text for electrical components grounded on most diagrams and photos.
I realize I'm way too wordy, sorry, and most ground info can be gathered from the photos & diagrams. Component info is under the ground number/heading anyhow as well as on photos or diagrams.
Below is a chart for on ground numbers with locations. Since the exact locations are unclear additional info in blue text has been added.
The individual grounds are below with images following the description.
G100. Near starter (4.0). No info found and a photo would help.
G100. Near intake plenum (4.7).
Conflicting info supplied by the FSM and needs verified.
For now the large/tall stud to right of the intake/plenum will be designated as G100. This insulated ground strap is connected between the large stud to the backside of the PCM case on one of the left bolts/nuts. I thought this ground was attached to firewall behind PCM but it is not and just on the back of the PCM case.
The OE number is 56038590 for this strap but not sure if available. This is the only rubber insulated half-flat ground strap found. The air box on top of the plenum needs to be removed to clean this ground good.
------------------------------------------------------------------
Firewall ground to right/left rear coil-on-plug studs:
This flat braided metal ground strap connects to a firewall stud above PCM and goes to far back passenger side coil-on-plug stud/nut. This is a 'Y' strap eyelet on the right rear coil-on-plug stud. While one strap connects from the firewall the other strap goes over top of the transmission bell housing and connects to the rear far back driver's side coil-on-plug stud/nut. Again, air box on top of plenum needs removed to reach these far back grounds.
---------------------------------------------------------------------
G101. Right inner fender, far forward (4.0 & 4.7)
Large black 6-gauge ground cable direct from battery negative terminal. Real poor design on my 04 since I couldn't back the bolt all the way out since the head was jammed against the PDC case. I cleaned the front/back of eyelet and bolt threads with small wire brush with bolt tip still in place. I've noticed on other WJ's a hole further forward used for this ground which makes more sense since PDC wouldn't be in the way.
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