Starting problem, relay board gone bad? Options

[arkitect]

I've been trying to solve my starting problem for awhile now. Finally realized today that the only power coming from the positive side of the battery was to the starter (the heavy wire). The other red wires going to the relay board were not getting any power due to a bad connection. But I used to get power to some of the pins on the 12 pin connection on the relay board...now I get nothing.

Is it possibe that these relay boards can go bad?

I am getting power to instrument panel..gas guage moves, oil light and large red light on top come on but the starter has yet to engage. The starter is good, had it tested.

Any ideas anyone?

Dave

[Dave_Darling]

The most common failure mode for the boards is that the connections between the pins where things plug in and the copper traces in the board get corroded. Yes, it can happen.

Another not-uncommon thing is corrosion where the ring terminals crimp onto the red wires.

--DD

[Tom]

Corrosion on the 12 and 14 pin connectors will cause this. Also see this thread.
http://www.914world.com/bbs2/index.php?showtopic=138435
I was surprised I was not having electrical problems also.
When the key is on and turned to start, you should have 12 volts to pin 6 of the 12 pin connector. If not you have something wrong prior to the 12 pin connector. That's where the large yellow wire goes, then to solenoid on starter.
As to not getting 12 volts to some pins on the 12 pin connector, you should have 12 volts there only at certain times and if the relays on the relay board are good and connections for the relays are clean and tight.
You should have power to the following that I am sure of,
pin 6 when key is turned to start if no power, try pin 1 of 14 pin.
pin 7 when key is on -coil power
pin9 when key is on- only used for sportamatic.
Pin 12 when ever fuel pump is running, power to AAR.
Not sure what is found at pin 2 and 4 - they are for the back-up lights.
Tom