

| Subject: | Re: ECU POWER SUPPLY? |
| From: | mark drillock |
| Date: | Sun, 1 Feb 2004 14:21:01 -0800 |
Page 24.61 of the latest Vanagon Bentley has an illustration of which pin is which on the ECU harness connector. Look at the pins while holding the connector horizontally. The top row has 13 pins and the bottom row 12 pins. Pin 13 is on the top right end. Pin 14 is on the bottom left end. With the ignition key ON, you should measure +12 volts or more between these 2 pins. If you don't, either the voltage is missing from pin 14 or the ground is missing from pin 13. Measure pin 14 again but put the other meter probe on bare metal of the chassis, anywhere, like a screw head. If you now have +12 then the ground is bad on pin 13. Pin 13 connects to a brown wire that is grounded to a screw under the back seat, near where the ECU is normally mounted. Make sure that brown wire is connected and has no damaged point anywhere on it's exposed length. If you still don't have +12 on 14 between pin 14 and bare chassis metal then you need to look at pin 87 of the ECU relay. There are 2 relays in the black box near the ignition coil. The socket with the most wires to it is the ECU relay socket. Pin 87 of the relay is where +12 leaves the socket and goes to the ECU. You should have +12 on pin 87 whenever the ignition key is on. If not, the relay may be bad, or the relay ground wire may be bad, or you may not have +12 on the black wires of the ignition coil though you previously said you did IIRC. Check again at the coil black wires. If +12 is ok there, check pin 86 of the FUEL pump relay socket. If it is ok there, check the pin of the ECU relay socket that has 2 solid black wires to it. The ECU relay and socket were changed in 1988 according to Bentley and are no longer interchangeable with the fuel pump relay. Since I have not owned or spent much time looking at this ECU relay area on an 88 or newer I will stop here for now. Report what you find and we can try to move forward. Mark John Carpenter wrote: > > Hi All, > I'm not sure which ECU pin is # 14, > but I'm guessing it is at one end or the other, > on the longer row of pins, > that has 14 on it :) > Anywho, no juice on either end of the row of pins. > Do have ground at # 13 though. > Where does the ECU get its power, and how is it fused or relayed? > thanks, > John C. > SLC, UT... > > I still have to check out power to the ECU, it appears! > > Thanks again to everyone for your help & expertise. > > It's just incredible, the bank of knowledge in this list! > > Synergy, for sure!
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