Fuel tank selector switch wiring

[bigdnew]

Curently in the middle of a gen 3 swap and i need some wiring advice. Purchased the pollack switching valve and the oem dash selector switch. the switching valve came with a six terminal toggle switch but the oem only has four terminals. does anyone know what four wires go to the the four terminals on the dash switch?

[glock35ipsc]

Did you look at the link I posted for you? There are two diagrams in that post. One shows the wiring to the switch. They should be power, ground, left and right. The other shows the wiring to the valve, then to the pumps and sending units (for the gauge).

[bigdnew]

yeah just still a little bit confused. the pollack valve has a wiring diagram but it shows how to wire the six terminal switch. i was wondering how to change that around so i can use the oem switch. it looks like the lead coming from the new wiring harness for the pumps goes straight to the switching valve and then i will have to have another hot wire for the oem dash switch as well. just want to make sure when i start building this harnes i get it right.

[glock35ipsc]

Originally Posted by bigdnew

yeah just still a little bit confused. the pollack valve has a wiring diagram but it shows how to wire the six terminal switch. i was wondering how to change that around so i can use the oem switch. it looks like the lead coming from the new wiring harness for the pumps goes straight to the switching valve and then i will have to have another hot wire for the oem dash switch as well. just want to make sure when i start building this harnes i get it right.

Do you have a way to scan and post their instructions? I threw mine away.

[87chevy.com]

ive been wanting to replace my bad valve.. i noticed it when bad when it took 1/2 tank for 40 miles and I thought i smelt gas... just poured the gas out the other side (no tank installed)

heres a link to the instructions on their site... that connector l ooks identical to the OE gm one....

http://pollak.thomasnet.com/Asset/IS-41_b.pdf

It looks like they just use a cheezy autozone like toggle switch. The connector sure does look like the GM. I will loook at the facotry diagram and compare it to theirs...

[bigdnew]

thanks man, hey bob there you go.

[glock35ipsc]

It appears to be wired the same as the factory switch. I'll compare the two tomorrow when I get back to the office, but you should be able to wire them the same.

I'll let you know tomorrow.

[Desert1957]

Originally Posted by bigdnew

Curently in the middle of a gen 3 swap and i need some wiring advice. Purchased the pollack switching valve and the oem dash selector switch. the switching valve came with a six terminal toggle switch but the oem only has four terminals. does anyone know what four wires go to the the four terminals on the dash switch?

[glock35ipsc]

OK, the Pollak's wiring diagram is basically identical to the OEM.

So, on the Pollak connector:

A: Right sending unit (OEM color: Pink/Black)
B: To fuel gauge (OEM color: Pink)
C: Left sending unit (OEM color: Pink/White)
D: Left pump 12V (OEM color: Tan)
E: Right pump 12v (OEM color: Gray)
F: Empty

At the OEM dash switch:

C: 12V from relay (OEM color: Tan/Black)
Opposite of C: Ground (OEM color: Black)
D: Left pump 12v (OEM color: Tan)
Opposite of D: Right pump 12v (OEM color: Gray)

Note that on terminals "D" and "E" that the wires (12v) will go directly from the switch to the valve. You will also need to tap a wire off of those to run to the pumps. The wires running from the switch have two functions: 1] is to power the pump, and 2] is to power the valve to make it switch to that tank/pump.

The OEM schematics for the switch only show terminals marked "C" and "D", and I can't find my drawing of the OEM switch, so just note above where I mention "opposite of xx" means directly across from that one.

The ONLY difference between the two drawings is the location of the power and ground on the toggle switch. If you are using the OEM switch, wire it like the above. If you are using the Pollak toggle switch, wire it like their diagram shows.

[bigdnew]

thanks guys for the help. so one more question. what is the difference between the '86 switch and '87, in regards to how it's wired to the switch. other than the obvious fuel pumps.

[menace121978]

Originally Posted by glock35ipsc

OK, the Pollak's wiring diagram is basically identical to the OEM.

So, on the Pollak connector:

A: Right sending unit (OEM color: Pink/Black)
B: To fuel gauge (OEM color: Pink)
C: Left sending unit (OEM color: Pink/White)
D: Left pump 12V (OEM color: Tan)
E: Right pump 12v (OEM color: Gray)
F: Empty

At the OEM dash switch:

C: 12V from relay (OEM color: Tan/Black)
Opposite of C: Ground (OEM color: Black)
D: Left pump 12v (OEM color: Tan)
Opposite of D: Right pump 12v (OEM color: Gray)

Note that on terminals "D" and "E" that the wires (12v) will go directly from the switch to the valve. You will also need to tap a wire off of those to run to the pumps. The wires running from the switch have two functions: 1] is to power the pump, and 2] is to power the valve to make it switch to that tank/pump.

The OEM schematics for the switch only show terminals marked "C" and "D", and I can't find my drawing of the OEM switch, so just note above where I mention "opposite of xx" means directly across from that one.

The ONLY difference between the two drawings is the location of the power and ground on the toggle switch. If you are using the OEM switch, wire it like the above. If you are using the Pollak toggle switch, wire it like their diagram shows.

WOW! talk about lay-mens terms! even i understand it thanks Bob! just helped me out tremendously!

[bigdnew]

Scratch my last thought. So the wire coming from my new fuel pump relay goes straight to the dash switch and then to the switch, got it