Relay board troubles, Power here and here but not there! Options

[dinomium]

Grrrr! Ok, when I jump across from pin 30 to 87, I have power to the fuel pump lead. There is 12+ volts at pin 30 AND pin 85. I have tried at least 10 relays, and they work for the fan socket. There is no signs of melting and just a little cracking in the "goo" underneath the board itself.
Is there some other "trigger" in the circut that I am missing? I have printed out the wiring diagams (color even) and am slowly going MAD I TELL YOU MAD!!! (IMG:style_emoticons/default/headbang.gif)
If anybody has a fault method they would like to share with me? (IMG:style_emoticons/default/confused24.gif) Or even better, a work around that I can use for this weekend to move past this issue? I promise to order a rebuilt board later this week.
Jet D
1974 converting from a 1.8 carbed application to a 2.0 fuel injection.
Trying to use stock wiring. Not too badly "skunked" by the PO
Thanks

[SirAndy]

ok, so ...

- you got 12V at pin 30
very good! that means the fuse and everything is OK.

- the pump runs when you jump pin 30 to pin 87
very good! that means the wiring to the fuel pump and the pump itself is OK.

so the problem is either the trigger current itself OR the relay socket.
are the pinholes corroded? they tend to do that. (IMG:style_emoticons/default/wink.gif)

there is 2 possible triggers:
pin 85 is triggered by pin 87 from the power-supply relay (the one above) which in turn also provides power to the FI brain.
pin 86 is triggered by the FI brain circuit.

pin 85 turns on the pump as soon as you turn on the key and the brain will shut it off after a few seconds unless you start up the engine, in which case it'll run continuesly (sp?).

sooooo, as soon as you turn on the key, you should see something (current) on pin 85. if not, check the power-supply relay.

the trigger for that comes off the same connection as the trigger for the heater fan relay, sooo, if the heater fan works as soon as you turn on the key, the trigger for the power-supply relay works. (IMG:style_emoticons/default/wink.gif)

if you do get the current, the brain might shut off the relay immediately (instead of the normal delay) and might keep the relay open.
do you have a spare brain to test with?


hope that helps a bit,
Andy (IMG:style_emoticons/default/drunk.gif)