Help: Test Power to DME
 

I have done something dumb. I was hooking up wires to my headlights and foglights with no problem, all while starting the car to make sure I was hooking up the correct wires. I must have started the car 15 times throughout this process with absolutely no problem.

Then out of the blue the car stopped firing. I mean it keeps cranking without starting. I checked and I am not getting any spark to the coil whatsoever and the fuel pump is not coming on. I cannot hear it clicking on when the car is trying to start.

I changed the coil as well as the dme relay. Still no spark to the engine and the fuel pump is not activated. I am now trying to troubleshoot.

It is my understanding that I need to first check to see if I have power coming into the DME and then going out of the DME. Can anyone explain to me in simple terms how to do this. I have a 1987 carrera. I took the seat out of the car and I am prepared to test the power at the DME. I just do not know what pins to check or how to go about checking the power source to and from the DME

Any help would be greatly appreciated.

If you have a factory alarm system, it could be acting up. The power for your DME relay goes through the alarm brain.

LJ851:

Thanks for the reply. I ruled out the factory alarm. Years ago I disengaged the factory alarm and so it is inoperable

oh man, sound like the reference sensor.

get your DVM out and check the OHMs on both speed and reference sensor

Here's a very helpful thread on testing the DME unit, as well as the speed and reference sensors.

http://forums.pelicanparts.com/porsche-911-technical-forum/573338-another-84-wont-start-quandry.html

good luck, and please keep us posted.

Kidrock:

Thanks for the site. went to it and read it and it gave me the exact diagnostic check that I needed.