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View Full Version : Serious main relay issues



ichbinsobose
04-06-2008, 12:26 PM
bf.c has been unable to help, thought I would try here:

Yesterday:

During one of the many times I was swapping my MS harness with my DME one of the three relays, or something else, in my ECU box started buzzing. Pull back on the connector it stops, start trying to plug it into the ecu again and it keep going. After some looking around I plugged it in, find that no relays are clicking over = no main relay = no ECU.
So, I have tried jumping all three relays to no avail (going from 30-87).
I checked the voltage in the 5pin relay I am assuming is the main relay (thick red cable running to it, the others are 4pins) and it gives me -2.6v at two places when using pin 85 "ground" on the relay, or +2.6v when using another pin as ground. This is with the 413DME plugged in and the key on. With no DME plugged in I get 0v. The pins should be getting 12v I believe.
Fuses are all fine, are there any in specific I should check? Replacing the main relay with a known good one did nothing.

Today:

Ok so there is a relatively thick red wire that appears to run from the battery, along the pass side of the car, through the firewall and into the ECU box. It has a little 10mm nut on its post and when I detach one end of it from the post the end running into the engine bay shows 2.6v like my relays, and the end running to the battery shows 0v. AT the battery its shows 11.8. GRR!

Ok, played with a bunch of garbage now I get it to read about 11v at the post. Now the relay post reads like 10.6 or so at the relay from 30 to 85 etc... but jumpering it makes the voltage drop to ~ .65 volts. WEAK! Im getting closer but got NOTHING yet. I love how a weekend of potential progress is wasted on hoping I can get back to square one.

whiskychaser
04-06-2008, 05:17 PM
Ok, played with a bunch of garbage now I get it to read about 11v at the post. Now the relay post reads like 10.6 or so at the relay from 30 to 85 etc... but jumpering it makes the voltage drop to ~ .65 volts. .
You mean you are getting 0.65v ac? When you cant even get your diuresis to work that must be a real sickener:( Best advice is to sleep on it and have another go with a clear head