ABS Computer sensivity

Hi all. I am troubleshooting my 92 with a dimmly glowing ABS (Amber) light. First pulled cluster looking for poor connections. Have good accumulator and pump seams to run fine. Ran “pin test” at computer as per repair book. Only trouble noted was minor- pins 1 to 2 at reservoir for level (normal closed) was at 0 ohms. Pin 9 - 10 at Abs computer was at a half ohm. Meter is pretty good quality and connections looked clean at pins. Is a half ohm level signal (worst case) enough to through out a dim and constant amber abs idiot light? Seams too low to trip as switch should be full contact or open. Other notes are flushed Dot 4 fluid after light acted up when I rebuilt front calipers. 55k total miles and believe fr wheel brgs pre load / play set OK. (Trouble source as per Mr. Kirbies fine book). Breaks work and pedal feals ok. Thanks much for any feadback or ideas!

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Always good to start from checking your buttresses structural condition… Then ABS ecu below it… Unless your ABS ecu is located elsewhere due to consistency in manufacturing…

Thank you. I have a convertible and the area looks rust free over rear wheel arch. Do you meen to say that a local ground or mount screw may trip me up?

Last detail- The amber dash light goes on and stays on with can in ‘run’, moving or not, so I discounted bad wheel sensor driving signals.

JP,
More info needed. Always start from year/engine - or simply complete your user profile, that will help every time…

1992 conv. car with 5.3 v 12. 55k miles. Trouble started when parked in doors- was ok- light next start.

Generally speaking, idiot lights don’t “glow dimly”. The whole point is either ON (bad news) or OFF (we’re OK).

Last time I had a fluttering check engine light, it was the computer.

You may want to consider that the device controlling the light has gone sour…

Thanks for reply. I first was hopping that the cluster picked up a “part ground” as the dim lite is weird. Now I’d like to avoid finding (and paying for) a 29 yr old compatible computer when I may be missing something simple-like a ground. On a good day I can rebuild a basic parts, but I am far from a “computer specialist”

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I am a computer specialist. (Servers and PC’s), Trained as an electronics tech.

If you are lucky, the bad ground will be found at the case the ECU is contained within.

Get a good qualilty meter and test continuity from the ECU case to battery negative (ground side). You should find near zero ohms, perfect continuity.

If faulty, find the broken or rotted out ground.

If grounded OK, research to find out how to communicate with the ABS computer. Older stuff often required grounding 1 pin and the light would blink to report codes.

If the ECU is functioning, it’ll give you a clue.

If ECU has crapped out… We drove without ABS for a just shy of a century. I recall when ABS was introduced, the demonstrators would pull the fuse and show how the car misbehaved.

Do you ever try to stop during a turn when the roads are wet/snowy?

Thanks for the info! I will have to investigate into those grounds tomorrow to see if those are good. I have been investigating some more complicated culprits like the ABS computer, but I will be sure to look into the basics like a bad ground before I dig too deep into this issue. Thanks again!

I would add that a failed pressure switch in the combined pressure switch can also cause the amber ABS light to illuminate via the ABS ECU (signal in @ pin 10, out at pin 27 to ABS light and Diagnostic socket).