Intermittent ABS Warning Light

[OldBlue61]

DId a quick search, but couldn't find anything on this, but like the title says, my '94 had had the ABS light up ocasionally. No rhyme or reason, no pattern. Could be on the whole day, other days it doesn't come on at all. Some days it comes on at start up, and turns off after 15-30 minutes. Load in the bed doesn't matter.

Any ideas on where/what to check?

 

[RonD]

You can unplug rear axle ABS sensor and look at connector to see if its clean inside, then plug back in
Do the same for ABS valve connector, in drivers side frame rail under firewall area.
These are the 2 outside connectors exposed to the elements, so can get corrosion

Unplugging and plugging back in connectors cleans the contacts that have been together for 20+ years

But until a part actually fails thats your best path forward

 

[RobbieD]

Some good first steps in order would be 1) pull sensor out of the rear axle and clean the face; then 2) pull the front rotors and do likewise.
Edit- BRAIN FART. No front sensors on RABS (was thinking of my Explorers); you only have the one sensor in the rear axle. Check the connections like Ron suggested, and consider cleaning the rear axle sensor.
You could get codes from the RABS (a '94 has Rear Antilock) system to get a more specific idea of what faults are occurring, but a common cause for the occasional ABS light being on is dirty pickup sensors. I know that a midwest truck that's seen salt won't be the easiest to wrench on, but just pulling and cleaning the axle sensor would be worth a shot- years of wear in the diff leaves a coating of metal particles on the sensor face which reduces its sensitivity.

 

[OldBlue61]

Thanks guys, and yeah, just rear wheel ABS. Pulling apart the connectors is what I was thinking, just not sure how many or where the connectors were. Actually this truck is fairly rust free, so it's not bad to wrench on. I saw the connector on the rear axle when I pulled the bed over the summer to change out the fuel pump, but the front one, it's in the driver's side frame rail under the firewall. Is there a picture anywhere so I know what I'm looking for? I figured I'd put a little silicon grease in the connectors when I pull them apart.

 

[RonD]

This is what the RABS valve looks like new: https://images.oreillyauto.com/parts/img/extralarge/a1c/122029-ang.jpg
4 wire plug in

This is what it looks like in the frame rail: https://www.therangerstation.com/forums/index.php?attachments/90-b2-rabs-loc-pic-jpg.70580/

You can sometimes see if from engine bay looking down, but can't reach it, lol

 

[OldBlue61]

You can sometimes see if from engine bay looking down, but can't reach it, lol

Of course! The story of my life!!

Thanks very much for the help. The pics are great.