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964 3.6T. Possible prob with R34 ABS relay - question re bridging pin


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Hi all

I am fault testing an intermittent ABS light/alarm warning and a speedo that dies at the same time, on my 1993 964 3.6T. So far I have done the "clock repair", re-soldering all fifteen pins on the back of the clock and the five pins on the speedo for good measure. Problem is still there.

Now I am testing the R34 relay by bridging pins 30 and 87. Could not reproduce the fault after 20 miles of driving (would normally happen well within that time). So it looks encouraging.

My question is: is it OK to leave the bridge in permanently (when switched off over-night and also when driving for the next few days)? I need to get several good runs in before being sure it is the relay. I have to leave the bridge in when driving as the fault may not happen until after 10 minutes of starting a journey.

If problem re-occurs with bridge I'll move on to speed sensors etc.

Any help appreciated. Thanks.

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I wouldn't leave the bridge installed. Is the relay common and possible for you to switch it with another relay? I'm not familiar with that relay but you might want to remove it's housing and check for faulty solder connection on the relay if it uses a circuit.

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This turned out to be a faulty R34 relay even though a lot of testing seemed to show it was OK.

The full story of the efforts to test the relay, and photos of the bridging test procedure (might help newbies like me coming to this problem for the first time) are at


My thanks to all those who helped me through this in this forum.


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