Dorkiphus.net - View Single Post - The DME Relay explained
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Old 04-19-2008, 04:32 PM
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Quote:
Originally Posted by pookie View Post
my #30 has power at all times. It is at 12+ volts with the key on or off.
Correct. This comes directly from the battery.

Quote:
Originally Posted by pookie View Post
My plug # 86 is hot with the key on
Correct. This comes from the ignition switch

Quote:
Originally Posted by pookie View Post
and my #87b is hot with the key on. My # 87b is also connected to the red/green wire in the front trunk
This is a problem. This is the OUTPUT of the DME relay to the fuel pump. It is supposed to go to one side of the fuel pump fuse, and the other side of the fuse goes to the pump. My guess is instead of hooking this to the fuel pump, you connected it to a +12V source in the fuse box. Again, the red/green wire isn't a +12V supply FROM the fuse box TO something else, it's +12V FROM the DME TO the fuse box and then to the fuel pump

Quote:
Originally Posted by pookie View Post
None of the other plugs are hot at all with the key on or off. Pin #87 is supposed to be hot with the DME relay in.
Yes. This is switched +12V to the ECU itself.

Quote:
Originally Posted by pookie View Post
And the kicker is with the DME relay removed my fuel pump still runs. That's not supposed to happen right?
Not at all. Start at the fuel pump and work backwards and find where you cross wired the fuel pump to a +12V switched source.
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1985 911 Carrera with a couple cosmetic only mods
2006 E90 330i
1999 E46 328i
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