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ABS relay overheating

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Old 11-13-2012 | 05:26 AM
  #1  
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galenmoloney
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Default ABS relay overheating

Hi all,

I have my car in the shop at the moment with my dads mechanic, I bought the car from a barn in Donegal. The bodywork was perfect ( a rare thing in wet Ireland), it needed a new clutch and the alarm was on for the ABS.
We installed a new ABS relay (the previous one was in a poor state of repair) but that seems to be overheating, the ABS seems to come on when breaking ( you can feel the grab/release sensation through the brake pedal).

The mechanic is now suggesting we change the fuse board. This seems a bit extreme to me as it would involve a lot of rewiring. I am going to suggest checking the sensors as I hear metal filings may throw them out, but it would seem odd that this would cause overheating in the relay?

I was also thinking of getting the durametric software to see if that might help but thought you guys might be able to provide some insight.

Thanks
Galen
Old 11-13-2012 | 07:03 AM
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ras62
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Don't even consider changing the main electrics board. You stand a good chance of causing no end of other issues. Better your dads mechanic is replaced by a Porsche trained tech at a good Indy imo.
ABS could be a sensor or ABS unit amongst other things, again a tech with the correct experience and/or diagnostic equipment will be able to identify the fault. You dont say the model and year of the car, they differ from each other.
Old 11-13-2012 | 08:46 AM
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I've not heard of a need of replacing the fuse board so that seems unlikely. I would get a diagnostic tool and see what the codes are if any. Also check to see the condition of the ABS controller in the front trunk. Water can get in an corrode the connector and circuit board.
Old 11-13-2012 | 08:53 AM
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galenmoloney
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Thanks guys,
sorry the car is a guards red 1990 Carrera 2. Bar the ABS issue the car is pretty perfect. Yep I thought replacing the fuseboard is a no no. I will try and get it across to the UK to a specialist.
I will see if I can get across and check sensors and ABS controller myself first.
Old 11-13-2012 | 11:56 AM
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Members "Crystalcranks" and "Pcar944" are in Ireland if I remember correctly, perhaps they know of a good mechanic more local to you.
Old 11-13-2012 | 12:16 PM
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The diagnostic tool for that car is pretty rare even at specialists. If you are able, I would check each wheel sensor is operational, 500-1500 Ohms across the pins. It is very hard (bloody impossible!!) to remove both the retaining bolt and the sensor if they have not been out before, so worth checking the readings from from the connector block. Also worth checking the ABS connector to the ABS unit located in the front of the boot. There are two relays in the main electrics, R34 Over voltage protection to ABS and R51 Hydraulic booster pump.
Is the ABS being triggered under normal braking, when exactly do you feel it pulsing? If it is pulsing the good news is the ABS is working fine!
Old 11-13-2012 | 12:48 PM
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My ABS relay has always been warm when the car has been running for a while and the ABS still works. I guess few of us take off the fuse box cover and check whether we have a warm relay. Is your mechanic looking for a problem that isn't really a problem?



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