Engine ground problem (I think)

TJW

Member
Joined
Apr 2, 2021
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31
Location
ontario, Canada
1998 Jeep Wrangler 4.0 L

I left my lights on for the whole night in the dead of winter and killed my battery. (a relatively new battery) A week later (weekend jeep driver)
I tried starting and just got a clickity-click out of it, so I tried using an old jumper pack and still nothing. I thought the jumper pack was defunct.
I put a trickle charge on it an it too didn't charge the battery. Just managed a single rotation on the start, then the famous clickity-click.
A mechanic said the starter was likely starting seize. We jumped it with a running truck. The same slow turnover one or 2 revolutions. I looked at the
connections on the battery post and the positive side had some what loose wires in the crimped terminal. I replaced the positive wire terminal.
Same slow turnover then nothing. I had the starter replaced. No change! Well I thought, now I'm down to the plus or ground to the starter.
I got a jumper cable and went from the negative to the manifold bolt on the motor block assuming the engine had a crappy ground.
Bingo! the starter worked perfect. I'm guessing that was the problem all along. My old starter was probably OK.
The mechanic just took my temporary ground wire from the engine manifold and just connected it to the body frame.
So, I'm wondering does the ground from the battery go to the frame and somewhere else the engine is connected to the frame to get the ground connection?
 
Isnt the main ground go from the neg terminal to the side of the block?
Neg side routs to the fire wall just behind the main wire harness and engine block just behind the distributor. There is a ground from the engine block to the frame as well that sits forward of the passenger side of the motor mount.
 
Neg side routs to the fire wall just behind the main wire harness and engine block just behind the distributor. There is a ground from the engine block to the frame as well that sits forward of the passenger side of the motor mount.
How to tell us you have a 97 without telling us you have a 97.
 
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There was a recent discussion on this you'd have to search for, but there is no specific ground to the frame. However @mrblaine found there is a ground path between the tub and frame via the front brake lines.
Unintentional at best and certainly not to be depended on for anything high current like a winch. I've dealt with more than one person who has managed to turn the brake hard lines red hot while screwing something up trying to install a winch.

A few years have a small ground from the block on the right side over to the frame near the motor mount. It is at best 12 gauge and more likely 14 gauge. The main grounds are from the battery and engine block to the firewall. Most of the electrical that doesn't carry a ground back to the battery uses the tub.
 
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@mrblaine

quick question: Should I run my Off-road light ground all the way back to the block or neg terminal? Right now I have them grounded with the headlights (right above the headlight on the passenger side)

My TJ is an 03’
 
@mrblaine

quick question: Should I run my Off-road light ground all the way back to the block or neg terminal? Right now I have them grounded with the headlights (right above the headlight on the passenger side)

My TJ is an 03’
It's fine for the headlights so no problem with the Fogs.

From what I have witnessed all of the TJ's equipped with the single coil had a factory ground from the coil bracket mounting stud on the engine to the frame.
 
@mrblaine

quick question: Should I run my Off-road light ground all the way back to the block or neg terminal? Right now I have them grounded with the headlights (right above the headlight on the passenger side)

My TJ is an 03’
As stated, the headlights, dash instrument cluster, tail lights, battery, and practically everything else is grounded to the tub.
 
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It is reported above as single coil specific which would be 97-99. I'll check the 99 later today and verify.
My early '98 (I have the slider HVAC controls) has that small gauge connection from the coil mount to the frame.

Unless there's a reason not to, I may replace it with a beefier ground strap.
 
My early '98 (I have the slider HVAC controls) has that small gauge connection from the coil mount to the frame.

Unless there's a reason not to, I may replace it with a beefier ground strap.
It is doing what it is supposed to do, why does it need to do more?