1999 Ford Windstar ABS warning light "on"

[marksatterfield]

Hi,

Seems the ABS warning light comes on after an intermittent time. Sometimes comes on as soon as engine is started, sometimes it doesn't come on after hundreds of miles. Usually it comes on within the first few miles.

I suspect one of the wheel sensors, but which one? The OBD reader only detects emission related codes.

* How are the wheel sensors tested? Are the sensors supposed to be tested while moving the wheel?
* Are the wheel sensors supposed to alternate between "open" and "closed" circuit when the wheel moves? If so, is the "open" really like a certain number of ohms (say, 5000 ohms?) and the "closed" something less (say, 50 ohms?).
* Could the problem be something other than the sensors? If so, what might that be?

* Are ABS code readers available for this vehicle? I own a code OTC Stinger code reader, but the Stinger appears to only read emissions related codes.

Thanks for your help!

--Mark

Mark Satterfield - Florida, Miami, Clearwater, Tampa, Melbourne, Orlando, Computers, Engineering

[Old Bubba]

Your Windstar is acting the same way my Explorer started out.
I think the light will eventually stay on at all running conditions.
Looking forward to the answers to your questions from the members!
I had a 2000 Windstar prior to buying the 03 Explorer, but no problems
with the ABS system on the Windstar.

[theoldwizard]

Originally Posted by marksatterfield

I suspect one of the wheel sensors, but which one? The OBD reader only detects emission related codes.

Yep ! I haven't seen a code reader that handles ABS. Probably because there are several different supplier and there is no standard interface or set of code like was mandated by the EPA for PCMs.

* Are the wheel sensors supposed to alternate between "open" and "closed" circuit when the wheel moves? If so, is the "open" really like a certain number of ohms (say, 5000 ohms?) and the "closed" something less (say, 50 ohms?).

Most wheel speed sensors are variable reluctance. about all yu can do is check for short or open at rest.

* Could the problem be something other than the sensors? If so, what might that be?

There are other sensors in the system, but these vary depending upon which brand of ABS you have (Ford bought from 3 different supplier for different vehicles in different years)

[mark v]

You unplug each sensor and measure the OHM's it puts out. Around 2000 OHM's give or take a few hundred.