DS_Porter  89 Burgandy

ABS Pressure switch replacement

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                              AC Delco 25530882 pressure switch for Teves ABS systems
        My original ABS pressure switch has been sticking and causing both the red and amber warning lights to
come on. Brake function is still good and the pressure pump cycles on and off normally as the pressure
drops which leads me to believe that only the switch contacts that control the fault lights are sticking.
I can reset the fault and stuck contacts by shutting the key off and pumping the brakes until all pressure
is relieved and then restarting it and allowing about 25 to 30 seconds to re-pressurize the system.
The pump contacts within the switch are independent of the fault contacts and therefore in my case I
was able to carry on with no panic. Still it is a condition that needs a speedy fix.
         So most of you know that the original pressure switch is not available anywhere....at all. A couple years ago
I purchased on Amazon an AC Delco 25530882 pressure switch because it appeared to be exactly the same
as what I was looking at on my master cylinder. Of course when I went to change it I found that the connector
pins were arranged differently.  (Why did they do that??!!)    I have done a local search for cars with the correct harness but I was quickly discouraged as most cars of that vintage have been sent to the crusher. So here is what I did...
        Small female spade connectors fit snugly on the new switch terminals but I needed to grind off one side as they
were a bit too wide. On the original Reatta harness connector I found that 16 ga solid copper wire fits snugly into
the harness wire sockets. I added a connector from an electronics shop for easy troubleshooting and disconnect. I
verified the original wire colors assigned to the terminal letters according to the diagram on the FSM page 8A-202-22       
After much checking and tracing and head scratching I have concluded that the switch diagram on page 5E1-74 of my FSM
has terminals A and C reversed. The diagram should be as I have drawn below.
  New switch works fine connected this way and the correct harness connector was not needed.


      

Pressure switch2.png

Pressure switch1.png

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Good job on the repair, but too bad you didn't ask around here. I have two NOS switches as well as a number of good tested used ones. Regarding your situation of your switch sticking and causing the lights to stay on, I have a pressure switch that does not trip the "Red" light. I kept thinking it was the BCM but thought I would swap out the pressure switch first and that fixed my issue.

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Some time ago there was a thread about using the switch that Ford used for the Teves system on the turbo coupes. I would believe it would have a Ford part number if it was the same one but the pinout looks similar to what I remember. 

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I sent a Ford connector to Machiner55 to try on the switch he bought [also a Ford] to cross over to our Buick units. It was never finished and Machiner55 has left the forum...

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Thanx for all your replies.

     Yes as you can see the ACDelco 25530882 switch is still available from RockAuto or Amazon.

And yes those spade terminals look to be correct but I removed the insulation and ground off one side

to make them narrow enough. To prevent the terminal connectors from moving or tilting I cut short pieces of

cable tie plastic strips and filled all the gaps between terminals and then ty-wrapped the entire bundle.

Never allow yourself to run out of ty-wraps. Silicone can be useful but this method can be reversed.

     Had I known that I was buying a different model switch I would have looked harder and queried this forum.

You guys continue to be a wealth of info and parts. Thank you all.

   Anyone who comes across the correct harness connector for this switch should snip it and save it. In my area

most all of the '86 thru '88 Olds Buick and Cadillacs have been destroyed. And my shoes got too dirty. Junkyards are

not as much fun as they once were.

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You could plug in your wired connectors, then spray inside the socket with WD-40 or PAM cooking spray- then carefully pipe in a "harder" silicone, such as Ultra black or Ultra blue, or a "bathroom type" caulking, let it harden, then carefully pull it out, to make a plug.

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