Voltage drop

[godschylde777]

I have a 2gb Eagle Talon AWD. You did a great write up on the wiring. So I am having a unique issue. I have 12v at the battery. 12v at the backup on pin 80. However, I am getting 8v on pin 12 and 25. I have checked voltage at the switch and it is 12v. On one of the relays I get 12v on com. On the relay where it says on by the pin it is on 8vs. I am at a loss. The ecu is seeing 12v ground. Any help would be appreciated.

 

[steve]

Work back to the MFI Relay and see what voltage you get at the inputs to the relay for the ECU with the key off. Quite a bit of the engine bay is powered from the same output of that relay as the ECU so what I'm trying to see is if the problem is before or after the MFI relay.

From your description it sounds like it's after but without pin # or wire colors it's difficult to be sure.

Looking at the 2GB diagram you should have battery voltage at both the red/black wires going to pins 3 and 4 of the MFI Relay (B-87). With the key off you should have 0v on the red wire to pin 1 and battery voltage at the blue/green wire to pin 2. With the key on, pin 2 should drop to close to 0v (gnd) and pin 1 should rise to battery voltage. Since your seeing 8v the next step would be to start disconnecting sensors and solenoids that are also connected to that circuit one by one to see if any are pulling the voltage down.