1980 with dual tanks HELP

[Mixup]

I have a 1980 pickup with dual tanks. It has a relay timer on the fuse box part #14014527. What is this for? I removed it and the truck still runs and the tanks seem to still switch. The problem is it kills the battery when left on the left tank overnight. From what I can find out it's suppose to time out after 30 min plus or minus 10 min. I think it's bad. Any help?

[Dually Don]

Here's what I found. Scroll down the page until you see the blurry pic with the GM box.

http://67-72chevytrucks.com/vboard/s...d.php?t=598604

[hatzie]

It's a timer relay to keep the solenoid tank valve switched enabling fueling from the AUX tank during extended cranking.

GM only used this on a small number of 1980 squarebody trucks.
http://67-72chevytrucks.com/vboard/s...54#post6354154

It's obsolete and a reliability issue. Id leave it unplugged.

[Mixup]

Thanks guys for your help. I still would like to know what will happen if you remove the relay? Would you have to run on just one tank?

[hatzie]

Originally Posted by Mixup

Thanks guys for your help. I still would like to know what will happen if you remove the relay? Would you have to run on just one tank?

I see Photo Bucket has made the 1980 NL2 relay thread un-usable... I have an un-adulterated copy of the picture.
According to the GM wiring diagram it's supposed to retain power for ±30 minutes (20-40 minutes)...



GM did kind of a poor job of drawing the internals of that relay.
It looks like you can't use the AUX tank without the relay or some kind of workaround.
A fairly easy workaround, that's reversible should you find a working time delay relay, would be a 6" chunk of 14ga SXL automotive wire and two male 1/4 disconnect terminals...
Plug this jumper wire into the relay socket from the Pink/Black Ignition power wire socket to the Green wire socket that provides the dual tank switch with power. This would bypass the relay and revert it the 1973-1979 system.

[Mixup]

Thanks Hatzie, I have a relay coming but just wanted to know if I can drive it until it gets here. I removed the bad relay and I'll leave it on the right tank and see what happens.

[Mixup]

Hatzie, I was just thinking about the jumper wire you said to put in. It wouldn't be a timer and would stay on all the time and kill the battery wouldn't it?

[hatzie]

No.

The relay is triggered by the Pink/Black Ignition power wire. This closes the relay switch terminals between the Orange battery power wire and the Green valve supply wire til the timer runs down.

Plugging in the jumper the way I suggested will tie ignition power to the Green valve supply wire. When you switch the ignition off the power to the valve is switched off.