ABS relay question....

So another of the items I have been fixing on my 88TC is an ABS light that remains on. I have followed the tech article here, pulled the relay, found the two wires to jumper, and the pump ran. But this was with the key in the off position. Should this run when jumpered even when the key is off? I did purchase a new relay anyways and installed it, but the light is still on. Before I went further, I wanted to find out about the key off and the pump running with the jumper installed. Thanks

Have you pulled the ABS codes?
http://natomessageboard.com/ubbthreads.p...mber=49770
http://www.tbirdheritage.com/turbocoupe/...-Chart.php

If you jump the 2 "switch side" terminals of the ABS relay, pump will run even with key off.

Many causes for ABS light on. Is the red BRAKE light on also? Do you have power braking? If the power brakes work, the pump, accumulator are functioning.

Damn, never even knew I could get ABS codes, great link, I will try that this weekend. Also, I DO have power brakes, they work fine, no issues and no red brake light. I will also check the fluid level again, I just did a cursory check and thought it looked full enough, but maybe not.

Correct way to check fluid level. Pump brake pedal 10 or more time with key off. Turn key on, and let the pump fully charge the accumulator (wait 20 sec after the read BRAKE and yellow ABS lights go off), and turn the key off. Check the fluid level. If you check the fluid level with the accumulator only partly charged, you will get a level reading that is higher by maybe 1/2" or more making you think the level is fine when it is actually low.

So I followed the link provided above to pull the codes for the ABS. Found the EEC test in the trunk, but it does not have the same pins as the link above. Instead of this
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/ o | \
/ | o | | \
--------------
mine does not have the upper o marked pin. Not even a wire going to it. I tried jumping the other combinations, but never got the ABS light to flash with key on. Does anyone know another test point or the correct combo of pins to jumper on this test point for an 88TC. Also checked the fluid level per the instructions above. Pumped the pedal 10 times, started the car, but I never hear the pump pressurize the accumulator, should this charge it every time the car is started? So the fluid level never changed. Thanks for the help so far.

After you pump the brakes 10 times and then turn the key on, how long does the red BRAKE light stay on (be sure parking brake is off)? It should stay on for several seconds, maybe up to 20 sec depending on state of charge of the accumulator. If the fluid level doesnt change and you dont hear the pump run, I dont understand how the power brake can work.

FYI, running the ABS codes will oNLY diagnose problems with the ABS part of the system and not the power braking part of the system. The power brake system and ABS part of the system are virtually independent of each other by design, so if the ABS part fails, you will still have power brakes.

I just went out and tried the 10 pumps of the pedal, key to on, listened for the accumulator. So had to really listen, it's quiet here now, listened past the door chimes and such, and heard it charging. good to go there, RED brake light out after about 11 seconds, still have the ABS light on. Fluid level is up to the arrow on the reservoir, so should be good. The power brake side should be good, as before I bought it, I test drove it, brakes felt good, could maybe use a bleed but good. I wish I could figure which pins to jump on the tester in the trunk to see what the problem is, instead of throwing parts at it. Maybe a wheel speed sensor?

Here is the sequence of events when you turn the key on (parking brake off), related to the ABS system--after pumping the brakes at least 10 times, ignition off:

1) The Red BRAKE and amber ABS warning lights come on;
2) There is the whirring sound of the pump charging the acccumulator. This should start out as a lower pitched sound and build to a slightly higher one;
3) There should be an audible CLICK, then the pump should shut off;
4) First the red BRAKE light should go dark (turn off), then the amber ABS light. Ideally this should happen in quick succession.

Open the hood and have an assistant stand near the ABS unit. Start the car. After a few minutes, slam on the brakes, as if in a panic stop. Ideally, you should feel a pulsating sensation from the brake pedal, which should drop and then rise back up. HOPEFULLY, neither the BRAKE nor ABS light will come on. Your assistant should hear the accumulator pump restart (might need an ear close to the unit to verify that), and the lights (if either or both appeared) should go off.

If either or both lights appear, it's not necessarily bad. If it happens more than once (and depending on how many times it occurs), it could signal a problem with the ABS part of the power brakes.

This is the pattern my TC has shown, through three ABS units (since 1991). YMMV, of course.

Sorry - that diagram is wrong. Jumper the bottom middle terminals. I knew I had done it before, but I couldn't remember what I did, so I just went out and did it again, but this time I took video.
[video:youtube]https://www.youtube.com/watch?v=F0uR7GRbWB4[/video]