ABS trouble, 1991 325iX

[rwtags]

I have a 1991 bmw 325ix with the abs light, I have read multiple times of the overvoltage protection relay, but more reading left me clueless on what to do next. Apparently their is no relay for the overvoltage, and nothing under the steering wheel, or passenger plastic in the cabin. I looked at the ABS pump area, and could not find a relay that was replaceable. I traced wires to the fuse box, but there where no relays that corresponded with the ABS system. Can anyone chime in? or tell me somethings to check? Previous owner said he replaced all the wheel sensors and that did not help with the ABS light.

[richardodn]

If I recall correctly, that relay was eliminated by '91. If your car has it, it is under the dash. Follow the basic troubleshooting here https://www.bimmerforums.com/forum/s...9#post28744779

[rwtags]

Yeah it does not have the relay there, i will have to rip the plastic cover off the abs pump to get to those two relays, except the screw is rusted and stripped..

[rwtags]

Further note, There is the check Brake light on the OBC, wondering if anyone would know if that would trip the ABS computer?

[richardodn]

Nope.

[Bob Plumbe]

I have a 1991 bmw 325ix with the abs light, I have read multiple times of the overvoltage protection relay, but more reading left me clueless on what to do next. Apparently their is no relay for the overvoltage, and nothing under the steering wheel, or passenger plastic in the cabin. I looked at the ABS pump area, and could not find a relay that was replaceable. I traced wires to the fuse box, but there where no relays that corresponded with the ABS system. Can anyone chime in? or tell me somethings to check? Previous owner said he replaced all the wheel sensors and that did not help with the ABS light.

Hi, on my rh drive 325i the aluminium cased over voltage relay was mounted on the upper side of the mounting plate for the abs brain, had to remove the glovebox then the abs brain before I was able to see the square silver coloured relay.
I had same problem as you, actually took me over a year to find mine, went through swapping the relays on the abs pump unit by mistake, swapped abs brain as well, it was during that swap that I spotted the over voltage relay hiding behind the abs brain mounting plate, its on the upper side of the plate out of sight.

once I spotted the relay it was easy to remove, I pryed it open, saw the burnt out fusewire, soldered new bit of wire across break and refitted to car, abs light no longer on and abs works

hope you find yours, its a quick simple fix when you do

[rwtags]

Bob, thanks for reply, i tested the relays on the ABS pump, they seem to work properly. This is driving me crazy, it must be the ABS box, or something. Anyone else got ideas?

[Bob Plumbe]

I think you misunderstood me, the relay you are looking for is mounted on the upper side of the abs brain mounting bracket, in the dash above glovebox and abs brain
I went through changing every relay I could find myself, none helped until I found the over voltage relay mounted above the abs brain.
its small square and has an aluminium body
my car is a rh drive 325i 1989, glovebox on mine is on left side of car

[rwtags]

I will look again later, you said it was above the ABS module, do you have airbags? i looked there a couple days agao, but couldnt fin anything, i will tear it apart looking. I tested some wheel sensors and they were bad, so i will replace those. I tested the ABS relays with a 9v, and they seemed to be working fine.