polecat702

First off, I don't know squat about electrical.
My ABS light and the bottom of my dash lights up after I drive the car. I'm assuming that the relays and computer module are working.

All the outer insulation on the looms going from the connector barrels are crumbling off from the shock towers down to the wheels, from both front wheels and from the connector in the spare tire well on the drivers side. The passenger side in the rear is still intact.

Should I change out all the wiring?

I had to look up how to use a meter, to check continuity. Still don't know what I'm doing.

ammonman

The warning coming on after driving a bit indicates the issue is most likely with the wheel sensor signals not getting to the control ECU or them being implausible to the programming. If the ABS comes on as soon as the car is started before moving off then the fault is most likely at the ABS ECU or ABS hydraulic unit from a blown fuse, bad ground, or defective relay.

The looms could be degraded enough to allow a loss of signal or a lack of proper shielding. The first thing to do is check and clean all the wheel speed sensors. Since the looms sound like they aren't in the best shape I'd not remove the wheel sensors from the hubs as you may cause more damage to the wiring. The front sensors can be accessed by removing the calipers and then the brake discs from the hubs. Clean the brake dust and debris off the sensor pins with brake cleaner and a soft toothbrush. Clean the signal rings as well. I believe the rears can be cleaned the same way. If cleaning fails to restore correct function you can test the sensor and wiring using a multimeter. I forget the amount of pulsed voltage each sensor should generate when the wheel is spun but a search should find the values. Check each sensor separate from the loom, then check the sensor from the loom connection in the engine bay if all the sensors show good when checked disconnected from the loom. The harnesses from the shock tower to each wheel are available, but not cheap ($150 each last time I had to buy one).

Hope this helps.

Mike

Tony

Check the power connection in the front driver side area of the engine bay. there is a big Phillips head screw that connects to big gauge wires that lead to the ABS unit.
just an idea.

unhook the battery first though.

polecat702

Thanks guys. When I was home 2 months ago I took all the wheel sensors out and cleaned them and metered them. All checked out.
Tony, I'll check out the big Phillips screw. I also have a complete loom for the front and rear. Just not the loom from the shock tower to the wheel, and from the spare tire well to the wheel. Just hate being a parts changer, till ya change the one that's not working.

ammonman

You should be able to meter the sensors again but do it at the shock tower connections. This should tell you which wheel signal isn't making it to the main harness, causing the fault. My bet is you will find one of the two front harnesses from the tower to the wheel has failed. I have had some luck using plastic bumper repair urethane epoxy to preserve the small crumbling two pin plugs. I coat them with epoxy before I try and remove them from the large barrel. So far they have held together. Once I have them apart I give them another coat to address any new or hidden cracks. The bumper repair epoxy is pretty flexible once cured and seems to be working well.

Mike

polecat702

The two front harnesses have all the outer insulation crumbling off, plus the one in the spare tire well, for the drivers side rear. I ordered them from 928 Int, but Tom sent the ABS harness instead. I'll be taking the parts back tomorrow, and doing a match up to get the right looms.

The ****ty part is I'm having 5 teeth pulled today at noon. I hope I'll be able to function on pain pills tomorrow. We're supposed to leave for New Orleans on Saturday, then to 3rd coast on the way home. I've got a ton of stuff to do on my car this week.

Bertrand Daoust

Joe,

Did you check each sensor to make sure there not grounded?
I had a problem with one sensor after removing it. When I put it back, I got an ABS warning.
It turned out that one sensor was grounded.

Easy to check:
- Check continuity between the two sensor wires. You should get about 1000.
- Check continuity between each sensor wire and ground. You should get nothing.
If you get something, the sensor is grounded.

Hope this will help.

polecat702

Yeah, I checked them. Thanks Bertrand.

The looms are shot, driving to Ca. tomorrow to get replacements.