Topic: Dead jeep... need ideas

[Mr_Random]

I was driving through the rain the other day, stopped to get some gas before I hit a cool trail someone took me on, and the jeep didn't start back up.

No power anywhere, or I should say VERY little. Doesn't appear anything got shorted from water damage, and the alternator is up awfully high away from water, any ideas?

I already replaced the ignition switch, seeing as it was cheap and easy anyways.

I cleaned up C101 on the interior, need to pull the exterior portion and clean that.

Replaced old/dirty looking fuses.

Added/beefed up ground and system power wires (4ga is the smallest now, majority are 2ga).

I poked around with a makeshift test light and found some semblance of power all the way up to the starter switch, but as soon as I use ANYTHING that requires electricity, boom, no test light.

I'm going to get the battery tested next, unfortunately I have a warranty for it at pep boys, and there is one within 100 miles of where I now live...

I'm also working on a budget of about $180 until friday, so I need to know what one thing will fix it, or what bunch of little things will. Either way, not much wiggle room.

Thanks for any help you guys can give!

Oh, and an interesting observation; when testing from Batt negative to the alternator CASE itself, I got power... It gives me a bad feeling about it, but I don't see how that works anyways. Clean out the alternator?

[sharpxmen]

did you try to jumpstart it (that is to rule out the battery being dead)?

[neale_rs]

Try jumping the terminals on the starter to see if it cranks directly.  If it does not, it is most likely your battery.

[chardrc]

you checked out your battery cables and cleaned the ends.. they can make things go crazy sometimes ..

[Mr_Random]

Yes to everyone, ha.

Replaced the terminals with marine style brass ones.

Jumpered the starter (used a big screw driver).

Tried to jump start it.

Heck, even tried putting someone else's battery in...

I really think the key to all of this has something to do with the alternator... finding power from the casing explains a dead short, but could a fried/corroded alternator do that, or is it something external?

[aw12345]

If the power fades away when you put a load to it like trying to start and after awhile the power comes back on its battery cables/ connections or a bad battery.
My money is on the cables somewhere or the clamps

[sharpxmen]

I really think the key to all of this has something to do with the alternator... finding power from the casing explains a dead short, but could a fried/corroded alternator do that, or is it something external?

you can disconnect the alternator an see if you still lose power

few questions:
can you turn your headlights on (with the keys out of the contact)?
what happens when you press the brake pedal without the keys in the contact (brake lights turn on or not)?
is the power disappearing when you put the contact on or when you crank it? 
do you get any sparks when you disconnect/reconnect the battery?

[neale_rs]

According to the '95 FSM there are positive and negative cables going to the alternator.  If you are getting power at the case, you would need to have a bad ground to the case and some internal (or at the connector at the alternator itself) path from the battery positive to the case.  It could be internal or extenal but you would also need to have a bad ground to the case, because with a good ground you would just be shorting the battery positive to ground (through the case), cables would get really hot or melt, etc. you would notice it!

[Mr_Random]

It's definately not cables or connectors, all are brand new, shiny, and clean.

There aren't any sparks when removing/replacing the cables on the terminals, but the same thing happened when I tried someone else's battery...

The casing should have a good ground, considering its' attached to the engine, and I did try to start it without the alternator plugged to the power, still got nothing...

I need to test the head light thing, I may have had the key in ACC when trying to turn them on.

All system power traces through the PDC and through C101 in two spots. I need to do some more extensive testing of what happens when I have the key out, turned to ACC, and turned to On. I know for sure there is no power during START, and I seem to remember testing whether there was any during ON, and there wasn't... only ACC, but haven't checked for sure with the key out...

I will make a list of things to test and get to work friday morning... I'm still suspecting something to do with the alternator, but will get a battery tester as a precaution.

thanks

[neale_rs]

The casing should have a good ground, considering its' attached to the engine, and I did try to start it without the alternator plugged to the power, still got nothing...

But you said before that you were getting power at the case.  How can you have both a good ground and power at the same time?

Have you been able to make it crank with the screwdriver?

[93yjFirstJeep]

If i were you, i would take off your alternator and starter and take it to a parts store like autozone and get them to test both of them, it is free after all.

[Mr_Random]

But you said before that you were getting power at the case.  How can you have both a good ground and power at the same time?

Have you been able to make it crank with the screwdriver?

Exactly what I asked myself! I'll test it again in the morning.

Yes I tried to crank it like that, in neutral with the parking brake on and the key in the "on" position.

and to the next reply; I'm planning exactly that tomorrow, as well as the battery.

Thanks guys, I'll report back tomorrow morning.

[neale_rs]

Ok, you tried to crank it...but did it crank?

[Mr_Random]

I tried to use the screw driver trick in other words.

Anyways, got starter and battery tested, they were fine. I'll be replacing the starter soon as it is ancient.

So, with that done I come back to the apartment and pop the hood of the jeep, get the battery in there, then decide to do some testing...

I was checking out my main ground, which I thought I tied to the block. In truth, it was, but only through the alternator/A/C compressor mount... which is aluminum... BIG mistake.

The Aluminum near the ground had "walked" away from the mount (flowing negative to positive), and turned any metal touching the bolt/ground into dust. I promptly relocated the ground to a STEEL part of the body, and VOILA, all power was back! Reinstalled the starter, reconnected all lines, secured everything back up, and woo, got a running jeep again!

Thanks guys, I'm kinda glad all this happened, because in the process I beefed up every part of my electrical system, and replaced some old parts anyways.

Thanks again for the help, and happy jeeping!

[neale_rs]

Thanks for the update.  Good to hear you got it running again.