Hi guys,

I hope this is the right forum section...

I have a 1993 RV with a Ford E350 Econoline chassis (G-body?).

The Rear ABS light is on, and the cruise control doesn't work. I took it to a Ford truck dealer, they think it's caused by the aftermarket LED rear tail lights that I installed.

Has anyone ever heard of this? Is there a fix, other than going back to standard-bulb lights? I put the LEDs in because the rear lights were always pretty dim, even after replacing bulbs and cleaning the contacts with a wire brush. I also think that I threw away the original lights (I replaced the entire assembly on each side).

Thanks.

Mike

 

I have my doubts but the way motorhome body builders do their wiring anything can happen. My guess is the sensor that is mounted in the rear axle housing. The rear tail light wiring on a coach is not Fords. The body builders just tie into the main harness.

 

That's what I was thinking too (the rear sensor). But, I would have expected the dealer to try that first...

Mike

 

LED lights will sometimes cause problems.The fix is to put a resistor inline

 

OK, what size resistor, and are there safety implications?

Mike

 

Here's what might be a stupid question: Would it be as simple as putting a voltmeter on a normal bulb and checking the resistance, then finding a resistor to match and put the resistor inline with the LED?

I really hate the idea of going back to normal bulbs, even more than taking these lights out and trying something else completely.

Mike

 

Actually, it would have to be in PARALLEL with the LEDs for it to do anything. As in, connect the resistor across the two wires going to the LED lights.

However, I'm not completely sure that the LED lights would do this. But then, I'm not up on 1993 RWABS.

If I had a wiring diagram, I could at least say it "might" have somethign to do with it, depending on how they figure out the brake pedal is depressed. If there is a separate switch for it, or they just tie into the feed to the lights and check for voltage drop.

You could, theoretically, measure the resistance of a standard bulb, but I'm not entirely sure it doesn't change after it's on for a split second (heats up). AND - that resistor will generate heat if it matches the resistance of the bulb. So, you need a high wattage resistor and some space around it.

What would I do? Probably get a standard bulb (two) and wire them across the LEDs and see if that makes the ABS light go out, and then figure out what to do.

 

Thanks. I thought of that too (trying 2 normal bulbs).

I did a Google search, and found some more info. Apparently, this is a common problem (the lights are Bargman), noted on a few RV forums.

Turns out, there is an aftermarket LED Load Resistor (not made by Bargman) that is sold specifically to deal with this issue. It's pretty inexpensive, and allows me to keep my new LED assemblies.

I'll look into this some more and let you know.

Mike

 

thanks Mike, definitely report back - it would be great info.

 

Will do. I've ordered the resistors, should have them installed early next week.

Hopefully, this won't dim the LEDs any...

Mike

 

Mike, you indicated you were going to try using resistors in the taillight circuits to fix the abs problem. Did you get to try this? Did it help? I also have a 1993 class C on the E350 cutaway chassis and a similar problem. I installed Terry's Peterson LED kit and flasher. Then before taking a trip I had the breakes and alignment worked on, then I discovered the ABS light comming on sporadically and the cruise control not working so I don't know which, if either, caused the problem. I'm inclined to try the resistors though before going to Ford. Any follow up would be appreciated.
Bob Crane

 

This thread was in 2006, but I had a similar problem on my 1993 mh and the rear speed sensor was bad. Replaced same fixed.