Intermittant ABS light '93 GC

Recently I have been getting an intermittant ABS light in my 1993 GC. Started seeing the light for the first time intermittantly during a
500+ mile trip (in 90+ deg weather) about two weeks ago.
The indicator light usually goes off after starting but sometimes it will stay on from start up (i.e. it doesn't come on after moving or anything like that). I checked the ABS module connector (clean/spotless), the ABS fuses, ABS sensor connectors, and cleaned off the sensors. The front toothed wheels are pretty rusty after 120Kmi.
I presume the only way to find out what's wrong is to have someone scan it but I was wondering if anyone has any other hints.
WB
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Many auto-parts stores (ie. AutoZone, Advance Auto Parts) will scan your error codes at no charge.

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barie did pass the time by typing:

Checked <> Cleaned
It may look just fine but be salted up and causing problems.
--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
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Which one may look fine but be salted up? I presume you mean the sensors and/or their connectors. In my case the big ABS module 40+pin connector was pristine. It looked like no water or anything had ever gotten into it.
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barie did pass the time by typing:

Any of the connectors but usually it's the big connector on the ABS computer.
http://www.revbeergoggles.com/Fixes/computer-abs.jpg
It might look fine but it's probably not. The 93 ZJ drains water from the hood right down on the top of that connector and it's subjected to air/road stuff that makes it in past the seals around the intake and left headlamp.
The place stuff gets into is under the connectors hood where the wires go in. If you take the back shell off and tap it you will probably see lots of dirt fall out. That's the side that gets contaminated with road salt/etc and develops small current leaks between wires. Since the ABS sensors are so sensitive, even the smallest current leaks can cause problems.
Usually have to clean mine about once every 2-3 years.
If you take the air filter top off and remove the filter, that spot makes a good location to set a plastic bag and clean the connector. You don't want to use connector cleaner over paint as it's also good paint stripper. The bag and a paper towel catches the excess fluid/debris.
The stuff I use is TechSpray, Econoline Contact Cleaner #1622-10S (Safe on _most_ plastics) :) Connectors are ok, soft rubber or vinyl tape ... that's another story...
I usually pull the ABS computer fuse before working on that connector although contact cleaner is non-conductive. If you use a brass brush to clean the connectors make sure you vac and examine for loose bristles.
--
DougW



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Ok I'll take a look at the backside of big connector where the wires go in this weekend.
Thanks,
WB
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In case anyone is still following this thread. I finally found the problem. I cleaned up the main connector but still had an intermittant ABS light all last week. I started ohming out the sensors when the ABS light was on and the problem was an intermittant right rear wheel sensor. Sometimes it was fine and other times is was bad. It would read 1.1KOhms (which is OK) sometimes, 1.8KOhms someother times, and open once in a while. Replaced sensor and everything seems ok so far.
WB
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I'm just really surprised it's still working: http://www.ifsja.org/tech/index.shtml God Bless America, ill O|||||||O mailto: snipped-for-privacy@aol.com http://www.billhughes.com /
snipped-for-privacy@city-net.com wrote:

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