95' GC Laredo - Odd Power/Start Problem

You are describing a vehicle that has lost it's body ground so it needs to steal the ground through another route. It has picked the radio as the ground path for now, but that won't last. The radio will fry.

I am not 100% for sure on the GC where the grounds are, but I believe one is from the battery to the fender and maybe one is a mesh strap across one engine mount. The Cherokee has a mesh strap from the rear of the engine head to the firewall.

Mike

snipped-for-privacy@nospam.com proclaimed:

The one guess would be an aftermarket radio, poorly installed.

It is a fairly simple circuit IF nobody has messed with it.

Plus 12 is fed off Fuse 12 in the PDC to the ignition switch and from there is fed [thru the clutch pedal sensor if manual] directly to the energizing side of the starter relay.

The ground side of the starter relay is fed thru the park/neutral switch on an auto transmission [or directly to ground on a manual].

You can measure for that +12 at the starter relay as someone turns the key to the start position. A braindead aftermarket installer or a bad ignition switch are about all that can prevent it from showing up, presuming anything else at all on the ignition switch works.

The ground is a bit trickier, but you can check for it again at the starter relay socket by having a friend put the tranny in and out of park if an auto...otherwise the ground should always be there.

The above just pulls the starter relay.

The actual power to the starter solenoid comes from Fuse 11 in the PDC and goes straight thru the starter relay normal open contacts to the starter solenoid. A bit Sears screwdriver can jump across that solenoid if suspect. You should be able to start the car by just jumping across the starter relay socket [with ignition on] from pin 30 [comes off the battery thru fuse 11] to pin 87 that feeds the starter solenoid.

Check very carefully near the alternator and battery to make sure that you have a very good and heavy wire straight from the battery to a nice tight ground at the fenderwall.

Still has the stock radio system. Only addition was a FM modulated CD changer which resides in the rear of theJeep, just in front of the reight rear wheel well. It's been there for years, no problems.

I'll have him check the grounds. They are under the hood near the battery and go to the fender, at east they do on mine.

The battery cable ground on the 95 ZJ goes to the inner fender right near the battery. There is no large ground from the battery area to the engine.

L.W.(ßill) Hughes III proclaimed:

Say what?

Umm try that again, you mean no ground from the engine to body, the main ground is from the battery to block with the secondary wire going to the fender. This means it likely has one mesh strap across an engine mount too.

Mike

Mike Romain proclaimed:

No, actually I said the ground cable from the battery goes to the inner fender.

The main ground from the battery doesn't go to the engine. This is the large number 4 wire tied right to the battery negative post.

I never did find a mesh strap across an engine mount when chasing an odd ball issue recently. Something tells me there has to be one, it is definitely not on the passenger side where you'd expect it to be.

Kept meaning to ask the tech, forgot.

None illustrated in the FSM, but it isn't overly illustrative on grounding points.

Care to bet?

Checked it against two other ZJ's of same year, including the service manager's.

Aware that there is likely a big ground somewhere, but as noted, the big black cable from the battery negative is very short and goes straight to the inner fender on the passengers side. This is specifically on the I-6, your mileage may vary.

L.W.(ßill) Hughes III proclaimed:

Had the engine ever been pulled, I'd have known it.

L.W.(ßill) Hughes III proclaimed:

LOL!

OK, try to find the ground for the starter....

I really don't know what you are looking at or thinking about, but the starter via engine block has the main ground. It never works any other way. Same as the starter has the main positive cable.

Mike

L>

As noted, I never did find the traditional hunk of braid *obviously* tied around a motor mount. I have a hunch I know where it is, but too lazy to poke under there until the next time something goes wheewhee and I am forced to. The ground is a pretty good one, I get less volt drop by far between the starter and the fender ground than I do from the battery to the starter--which is still well under spec.

Mike Romain proclaimed:

You have no engine to battery ground cable?????

You only have one cable off the battery to the fender only????

Holy crap! That is really screwed up wiring.

Mike

L>

Still trying to act like you know something, billygoat?