mlneville88

Ok all you wiring experts.... My battery started draining over night. When I check it the current draw with an AMP meter, it is drawing nearly 2 Amps without the key in the ignition. I've tracked the source back to the DME relay. Now for the $64K question... When I pull the DME relay out the draw drops way down to like 60 to 100 mA.. which is good and expected.. radio etc.. after looking at the wiring diagram it appears that pin 3 on the relay is the switching power and should only be energized with the ignition key on, however, I see 12V all the time. Now maybe my assumption is wrong, so i'm looking to you all to set me straight here. Could my issue be just a bad DME that is misbehaving? I swapped out the ignition switch thinking that might be the issue but i'm getting the same behavior with the newly used switch. Thoughts?

Moparboy72

The DME should control its own power; it will power down after a delay when it performs a few routines. Such as MAF sensor burn off, though this should only last a few seconds. There should also be a permanent 12v supply via 55-pin DME terminal 18 for fault memory, but this would be very low power consumption.

thomasmryan

Do your windows and radio still operate until you open the drivers door?

mlneville88

Thanks guys for the replies.. I'll have to double check the window and radio functionality. I will do that tonight. It just seems odd that the ignition supply to the DME relay would be hot all the time. Logic tells me that the DME relay would be energized and therefore the DME would also be energized too.. I was just thinking that ignition source to the DME relay should be 0v until the you turn the key to the ON position then everything would come to life.

Sdale944

While not aligned with your DME question, the prior owner of my car was plagued with battery drain issues for a very long time. I discovered the passenger's door drains were plugged with debris and the high water mark was about 5" up the door panel....submerging the door lock wiring connector. I cleaned the drain and rerouted the door lock wiring high in the door. Battery stays charged now for very long periods of inactivity.....just another thing to check for.....

mlneville88

Thanks I will certainly check that also.. every little thing helps. Also would one of you be willing to pull out your DME relay and without the key in the ignition check to see if there is 12VDC on the ignition switch wire that feeds the relay? I'm trying to see if this is normal operation.

Moparboy72

With the key off and DME relay removed; terminal 30 and 86 have battery voltage.

ECU Doctors

What if you remove the DME control unit? I would think more like an issue around the relay box wiring itself...

I haven't since a battery drain issue coming from the ECU so those are my 2 cents.