Causes for ABS light???

[atomicjoe23]

Thanks JoeCool85

 

[AgPete139]

Good job, and thanks for the update and "completing" this thread. Glad you found the culprit. I'm gonna rep you now.

 

[joecool85]

Good job, and thanks for the update and "completing" this thread. Glad you found the culprit. I'm gonna rep you now.

I appreciate it. I completed my part of the thread, but I'm not the OP - that was AtomicJoe. I'm assuming his truck isn't fixed yet.

 

[AgPete139]

Oh, snap. My bad. Joe, did YOU fix the problem yet?

 

[atomicjoe23]

Not yet. . .I will have time to crawl under it tomorrow and start testing the sensors that have been pointed out. . .

. . .I've been fixing some of the other small things on the Ranger, working on our '49 Jeep Willy's pick-up, and trying to finish up a friends '74 Chevy C10 2WD shortbed that I'm building 4-link rear for in the meantime. On the upside of these other fixes I just boosted my mileage by 4 MPG with the combination of repairs that I made. . .bumped me up to an average of 20 MPG. . .YEAH!!!

If I find a potential culprit tomorrow I'll post-up and then again after I replace the suspect sensor.

 

[atomicjoe23]

Ok, ended up being my ABS speed sensor on the rear axle. $15 from Advance Auto and I'm good to go.

That said, people need to stop referring to it as the VSS (vehicle speed sensor) because it confused the heck out of me. It's the ABS Speed Sensor, the VSS is on the transmission and is a different part. THAT is why the speedo will keep working even when the sensor on the axle is bad.

How did you end up determining it was bad. . .I'm going to go check my sensors right now.

Thanks!

 

[atomicjoe23]

How exactly did you check the resistance on the front ABS sensors??? There doesn't seem to be a quick disconnect, at least not close to the sensor itself. . .all I can see is a small metal "pole" at the end of the sensor itself.

Thanks!

 

[atomicjoe23]

Found the disconnect behind the front bumper.

I checked the resistance, but I couldn't get a reading at all??? Not gonna claim that electrical troubleshooting is my forte, but??? I tried to check resistance between the metal pole in the sensor and both of the metal electrodes in the quick disconnect and tried all the resistnace ranges on the multimeter with no luck. . .

. . .but could this be the problem???

Sorry that the picture is clocked, but I forgot to rotate it when I put it on the web and I couldn't get it to rotate.

What is this line that I'm pointing at??? Looks like a vacuum line if I trace it back, but it's all corroded and actually broken the hose connects to the metal line going into the hub. . .this is on the passenger side. . .I haven't checked the drivers side yet.

Thanks for the help!

 

[atomicjoe23]

Just checked the driver's side and it isn't corroded like the passenger side. . .and the rubber hose isn't all dried out and cracked. . .it's not super pliable, but it's not horrible. . .may be time to replace some vacuum tubes. . .not sure what to do about the super corroded metal tube going into the hub though. . .

. . .oh wait are those for the 4WD???? I don't know why I didn't think about that!!!

I wanna make sure I was looking at the right sensor too. . .is the sensor held into the hub by the socket head cap screw just below my finger the ABS sensor. . .just want to make sure it isn't the sensor that lights up the 4WD light.

Thanks!!!

 

[joecool85]

How exactly did you check the resistance on the front ABS sensors??? There doesn't seem to be a quick disconnect, at least not close to the sensor itself. . .all I can see is a small metal "pole" at the end of the sensor itself.

Thanks!

There is a wiring harness coming off from it that is a foot or two long, comes in front of the wheel (both sides do this) and hangs between the bumper and the front of the wheel. Disconnect this clip and you'll see two electrodes.

 

[atomicjoe23]

So do I check the resistance between the two electrodes or the resistance between the metal pole on the sensor and the each electrode separately?

I tried both methods and I didn't get any readings. . .as in the display on the multimeter didn't do anything regardless of which scale i was on, and yes I was using the ohm section of the multimeter.

 

[joecool85]

So do I check the resistance between the two electrodes or the resistance between the metal pole on the sensor and the each electrode separately?

I tried both methods and I didn't get any readings. . .as in the display on the multimeter didn't do anything regardless of which scale i was on, and yes I was using the ohm section of the multimeter.

Resistance between the two electrodes in the plug not the socket. IE - the wire going towards the hub not towards the rest of the truck.

Your multimeter should be set on 2k (2000) ohms. Are you sure your meter is working?

**edit**
I have a hard time believing that BOTH your front sensors are reading 0 ohms. That said, even if they are I would spend the $15 and swap in the new rear sensor first since it is so cheap and is probably the failed sensor anyway.

Also, apparently when one of the front sensors go your ABS will pulse when you are on the brakes and turning sharply at low speed. IE - 10mph turn to the right most of the way and apply your brakes, then the same to the left. If everything is smooth it's probably your rear sensor that is bad.

 

[tx3nc]

I'll bet the reading he got was not zero ohms, but it was OL, the usual digital display for a resistance too large to measure in the range selected. IE the resistance reading was infinite or open circuit.

 

[atomicjoe23]

Resistance between the two electrodes in the plug not the socket. IE - the wire going towards the hub not towards the rest of the truck.

Your multimeter should be set on 2k (2000) ohms. Are you sure your meter is working?

That's what I had it set on initially, when I didn't get a reading I went up the scale with no luck.

**edit**
I have a hard time believing that BOTH your front sensors are reading 0 ohms. That said, even if they are I would spend the $15 and swap in the new rear sensor first since it is so cheap and is probably the failed sensor anyway.

I can get a used rear sensor out of a 2000 Mountaineer for free this Saturday. . .I will try that before I buy a new one.

Also, apparently when one of the front sensors go your ABS will pulse when you are on the brakes and turning sharply at low speed. IE - 10mph turn to the right most of the way and apply your brakes, then the same to the left. If everything is smooth it's probably your rear sensor that is bad.

Everything is smooth during low speed turns so it probably is the rear sensor then. . .

I'll bet the reading he got was not zero ohms, but it was OL, the usual digital display for a resistance too large to measure in the range selected. IE the resistance reading was infinite or open circuit.

There was no "L" just 0.

 

[tx3nc]

That's what I had it set on initially, when I didn't get a reading I went up the scale with no luck.



I can get a used rear sensor out of a 2000 Mountaineer for free this Saturday. . .I will try that before I buy a new one.



Everything is smooth during low speed turns so it probably is the rear sensor then. . .



There was no "L" just 0.

What does the meter read when it's set in the ohms mode and not connected to anything?