no ground to fuel pump relay

[scottinAZ]

Ok, interesting problem here. car is a 1987 325iC, with automatic.
I am not getting ground through the DME to run the fuel pump. I DO have good spark, and if I jumper the relay to ground, I can get the car to sputter and pop (havent tried for full start yet), so the information is there. Does anyone know the path for the ground wire for the relay, is it straight back to the DME through the engine harness, or does it go through other connectors (where some asswipe may have spliced in an alarm)

[StereoInstaller1]

Do you have the ETM downloaded?

[scottinAZ]

Do you have the ETM downloaded?

I do, and though it doesnt show any other connections between DME and relay, it doesnt (always) mean there isnt one that Im not seeing.

also, it doesnt matter (ive tried both ways) whether I have the CPS swapped with the impulse sensor, I dont have ground either way.

Im assuming if I had the CPS not correct, then I would not have spark, although I could be mistaken.

I almost need a checklist of what the DME needs in order to provide the ground to the fuel pump relay, so that I can check them one by one. The ETM is helpful here, although it is far from foolproof (and I am sometimes a fool)

[jlevie]

It is a straight run from the relay socket to the DME connector. Ohm out that wire and if it is okay and there is no evidence of modifcation to the harness, replace the DME.

[scottinAZ]

It is a straight run from the relay socket to the DME connector. Ohm out that wire and if it is okay and there is no evidence of modifcation to the harness, replace the DME.

I already swapped DME's

Ill ohm out the wire shortly

What inputs would be possible to screw up that would cause no ground? just the CPS, Impulse wires?

UPDATE: Wire is confirmed to be crapola. Showing about 26meg on the run (essentially open). Shit. now I need to get into the damn harness to fix the damn thing......

[StereoInstaller1]

UPDATE: Wire is confirmed to be crapola. Showing about 26meg on the run (essentially open). Shit. now I need to get into the damn harness to fix the damn thing......

Well, at least you diagnosed the damn thing instead of blindly swapping crap and guessing...now go kick its ass!

(check C101 first)

[scottinAZ]

Fixed...
Fucking thing was crimped about an inch below the relay. One bit of solder, one inch of heat shrink, and presto chango, working fuel pump....