Help: Test Power to DME

[Srwilliams]

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.

[AKCJ]

Well, if you want to run down a battery, I can't think of a better way than to start a car 15 times. That would do it. Charge up the battery and try it. You could check the battery voltage also.

You say you have a "87 carrera". Are you in the wrong place?

[egil]

If you started the engine 15 times and only let it run for a few seconds every time, I would also have suspected fouled plugs.

[AKCJ]

Originally Posted by AKCJ

Well, if you want to run down a battery, I can't think of a better way than to start a car 15 times. That would do it. Charge up the battery and try it. You could check the battery voltage also.

You say you have a "87 carrera". Are you in the wrong place?

Reminds me of the time I flushed the brake fluid on my first car. I spent quite a bit of time pumping the brakes to get all the old fluid out and the new fluid in. The brake lights were enough to run down the battery so the car wouldn't start. . . .


To the OP - did you get it figured?

[rick13]

pull the dme plug, turn ignition to "on". get a multi-meter and check for 12v at pins 18 and 36. they are the 2 pins at the end of plug.

hope that helps

rick

[944 Ecology]

It was an 84 911 and he found the answer on the 911 board.

[rick13]

i have an '87 grand national t-type... errrr.... i need help with air pressure in my tires. battery has 12v, key is in ignition... oh, and it's only flat on one side

[rick13]

no no. i mean '84 le sabre...lol

[egil]

Originally Posted by AKCJ

Reminds me of the time I flushed the brake fluid on my first car. I spent quite a bit of time pumping the brakes to get all the old fluid out and the new fluid in. The brake lights were enough to run down the battery so the car wouldn't start. . . .

21W times two, probably, so 3.5A total current drain. Even if you kept your pedal continuously pressed for an hour, that would only rob 3.5 Ah from the battery. So your battery would be at well below 10% of its rated capacity for this to happen. I guess one could see it as a sign one should consider replacing the battery