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Don, you are correct, it does have ABS. The PO told me it didn't have ABS because of the 4x4 conversion, but I looked at the front brakes and they are indeed still wired up as ABS. I've never had to do a "spirited" stop so have not noticed during driving it. So you think it could be related to an ABS relay?
I really don't have an opinion on what is failing. Electrical problems have too many possibilities to predict which one it is. Sometimes it's a component failure, but mechanical damage (wires rubbing, rodents, corrosion) is always a possibility.
I personally would not replace parts until I have verified the source.....at a minimum have some data that strongly points to a source. Have a plan for the next time you catch the brake lights stuck on.
Forscan lite will show all codes. The ABS may be working as far as the error codes are concerned, but there could be something inside that has failed.
Here is the wiring diagram showing how the ABS module turns on the brake lights. The module is circled. It provides a ground that turns on the stability traction control relay. The yellow trace shows where 12v goes to the brake lights. Is it possible for the ABS module to turn on the brake lights if the van is OFF...? I don't know. But you need to determine if the lights were ON before you shut the van OFF and maybe the switch in the ABS is stuck.
This is only one possibility.
******edit******
The ABS module may be OK but the wiring may be grounding out on the frame somewhere and this is turning on the relay and brake lights.
Last edited by Don Ridley; May 4, 2026 at 04:35 PM.
I really appreciate your input Don. I'll figure this out at some point and let everyone know. I found them on last September, then I saw them come on a couple days ago, I have to think they have come on more than those two times so they may eventually turn themselves off, otherwise I would have noticed them on or had a dead battery at some point.
That switch has a strong spring that provides a lot of force to turn the switch off. But if the mechanism (circled in red) got damaged or rusty, it may get hung up. This may explain the change when the door was shut. Easy to replace and under $40.
Last edited by Don Ridley; May 12, 2026 at 06:24 PM.
I did some online searching and have read where the brake light switch can go bad and leave the brake lights on all the time. So an intermittent brake light on, then off, seems very plausible for a bad switch. Also, it can affect the cruse control since the signal to shut cruse off comes from the same switch. My cruse control doesn't always engage so I was hoping the switch replacement would fix both. Got the new switch and it's an easy remove/replace. First test drive there's no change in the intermittent cruse control engagement, I'll just have to wait and see if the brake light issue is fixed.
