Crank No Start and Funky Voltages at Main Relay

[usualdeviant]

Key on engine off, I get battery voltage at 2 of the pins, but very low voltages (not zero) at the others. .5, 1.5, somewhere in there. Then if I reverse my lead from ground to power (junction block), then it's more like 12, 11, etc. So a short to ground is what I'm thinking. I cut the heat shrink off part of the harness between the relay and where it branches off to C101 and it is looking nice. Noticed 16 ohms between pins 2 (ground) and 27 (start input) on the DME connector. New dealer ignition switch installed maybe 2 years ago. Any thoughts on this? Obviously I should test that start input wire some more but just not sure which way to go yet.

[usualdeviant]

Battery Voltage KOEO
+12.28V

Main Relay Voltages (V) at connector, relay removed
30 +12.25 -0.0 (hot at all times - ok)
85 +0.47 -11.8 (ground from DME - should be +0.0 -12.25)
86 +12.27 -0.0 (hot at all times - ok)
87 +0.88 -11.32 (power to fuel pump relay - should be dead)
87a +1.41 -10.85 (power to DME - should be dead)

Correct me if I'm wrong. I just sort of made up the "a" in 87a, I know the ETM calls it 87 for both 87's.

Also I have 3 known good DMEs, none of them have an effect. I found the 16 ohms resistance in the start input wire was the OBC relay. Jumped the connector and did not change main relay voltages, only eliminated resistance on that wire. Anyone ever ran into this issue before?

[uturn]

Did you replace relays? because the 30 pin location is swapped between Type A and Type B relays

[usualdeviant]

I'll be a mother. Yes. I replaced the main and fuel pump relays awhile back. For whatever reason, I used a 5 pin for both. Whatever, it worked. But yeah looks like I have a type A and a type B here...

[usualdeviant]

I used the ETM to determine which relay to use for the main. Then just used a 4 pin for fuel pump. My ICV is buzzing once again! So weird. I'll have to tuck wires away behind the water pump pulley first, may take a few days, but then I'll fire it up (or try) and see what happens.

[usualdeviant]

Quick update, I'm late for work. The correct relay solved my problem, the car starts every time with no glitches while driving. I am still trying to understand why some of the pins have some ground and some power, but the car is not complaining.

[moatilliatta]

Fuseable link by battery will cause low voltage issues at main relay. Check for corrosion.

[usualdeviant]

Thanks but I did actually replace it with an inline fuse holder, 60A fuse, and proper crimps, not long ago. Checked the fuse and still good. BTW, car is still great, just got back from another successful adventure!