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Old 05-05-2010, 10:58 AM
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funola funola is offline
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Quote:
Originally Posted by diesellac View Post
So i tryed funola's egr thing and its not working out for me and was wondering if its because i have an 85 tach with the 3 prong in back. or because i was misssing a ground because i soldered the 12v part in back and did the red and black wire pair and put that in.
I am not familiar with the 85 tach. What's the difference between the 3 prong and 2 prong tachs? The soldering I did was to provide switched power to the EGR computer/tach which I doctored up. You can do a little trouble shooting with a DVM. Check that you have 12V power and ground to the tach amp and the tach. If not, fix that first. Then put the DVM on low ac scale and measure the output of the tach amp with engine idling. You should see a voltage there (maybe about 100 mv). If you rev the engine, the voltage should go up. If it goes up, that's an idication the pickup and tach amp is working. Now you want to check that the tach amp output is getting to the tach so check for the output from the tach amp at the tach, you should see the same there. If you have signal at the tach and it has power and it is not burned out it should work.
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