Need some help figuring out how to wire my dual saddle fuel tanks

[WranglerTJForum]

The time has come to re-wire my dual saddle fuel tanks on my 1973 K10.

I went ahead and purchased the Pollack valve from the newer (EFI model) K10s. It came with the Pollack valve, a DPDT switch, and this wiring diagram:

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This wiring diagram makes complete sense to me. Where I am struggling now is I want to include a fuel pump relay in order to take the load of the DPDT circuit.

I'm using this relay:

Amazon.com: Mr. Gasket Relay Kit - Fuel Pump 30 Amp : Automotive

Buy Mr. Gasket Relay Kit - Fuel Pump 30 Amp: Fuel Pump - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

As I understand it, the relay should be wired as such:

	1. Battery +12 V → 10 A fuse → Relay Pin 30 V
	2. Relay Pin 86 (coil trigger) → should get switched 12 V from the DPDT switch, not constant power.
	• The DPDT switch position determines whether the relay coil energizes. • That's how the relay "chooses" between 87 (Main pump) and 87a (Aux pump).
	3. Relay Pin 85 → chassis ground.
	4. Relay Pin 87 → Main pump positive feed.
	5. Relay Pin 87a → Aux pump positive feed.
	6. Both pumps ground directly to

Makes perfect sense thus far.

The part where I get confused is how this relay integrates to the original wiring diagram.

In the original diagram that came with the Pollack valve, the DPDT switch has 4 wires going to it.

1) Ground
2) 12V
3) Main fuel pump
4) Auxiliary fuel pump

Do those wires going to the DPDT remain unchanged with the addition of the relay? Given that the relay now feeding the two fuel pumps directly, I would imagine that the DPDT now only has a ground and 12V wire going to it, but then that has me confused about how it's able to discern between the main pump and the auxiliary pump.

I'm sure I'm overthinking this but since I'm not an electrical guy I want to make sure I get it right the first time.

 

[WranglerTJForum]

I think maybe I've got it now, does this sound correct?

You must be registered for see images attach

 

[Ricko1966]

The time has come to re-wire my dual saddle fuel tanks on my 1973 K10.

I went ahead and purchased the Pollack valve from the newer (EFI model) K10s. It came with the Pollack valve, a DPDT switch, and this wiring diagram:

You must be registered for see images attach

This wiring diagram makes complete sense to me. Where I am struggling now is I want to include a fuel pump relay in order to take the load of the DPDT circuit.

I'm using this relay:

Amazon.com: Mr. Gasket Relay Kit - Fuel Pump 30 Amp : Automotive

Buy Mr. Gasket Relay Kit - Fuel Pump 30 Amp: Fuel Pump - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

As I understand it, the relay should be wired as such:

	1. Battery +12 V → 10 A fuse → Relay Pin 30 V
	2. Relay Pin 86 (coil trigger) → should get switched 12 V from the DPDT switch, not constant power.
	• The DPDT switch position determines whether the relay coil energizes. • That's how the relay "chooses" between 87 (Main pump) and 87a (Aux pump).
	3. Relay Pin 85 → chassis ground.
	4. Relay Pin 87 → Main pump positive feed.
	5. Relay Pin 87a → Aux pump positive feed.
	6. Both pumps ground directly to

Makes perfect sense thus far.

The part where I get confused is how this relay integrates to the original wiring diagram.

In the original diagram that came with the Pollack valve, the DPDT switch has 4 wires going to it.

1) Ground
2) 12V
3) Main fuel pump
4) Auxiliary fuel pump

Do those wires going to the DPDT remain unchanged with the addition of the relay? Given that the relay now feeding the two fuel pumps directly, I would imagine that the DPDT now only has a ground and 12V wire going to it, but then that has me confused about how it's able to discern between the main pump and the auxiliary pump.

I'm sure I'm overthinking this but since I'm not an electrical guy I want to make sure I get it right the first time.

Terminal 86 gets a switched constant power as long as there is power on 86. Power out is on 87a when 86 loses power,power out switches to 87.

 

[Broken85]

I think I sent this too you before. Use the dark green and light green wires as triggers for the relay. I think I actually have the left and right reversed in this diagram though. I think light green is left and dark green is right.

 

[LeperGnome87]

Go with the 5 pin relay. Toss the selector valve and wire it into your switch. Pin 30 constant power to pin 87a which should be wired to your left pump. Pin 87 to right tank. Pin 86 to ground. Because 87a and pin 30 are connected internally

 

[Ricko1966]

Pin 85 to switched power,left out of the above post,without it the relay does nothing.It would just be a junction block. And I would not eliminate the selector valve.

 

[LeperGnome87]

Thats up to you. I switched everything to in tank pumps, because at some point im going to throw in a holley sniper 2 kit

 

[Ricko1966]

Thats up to you. I switched everything to in tank pumps, because at some point im going to throw in a holley sniper 2 kit

Intank pumps is great, same way I'd go,but losing the selector valve is not a good move. That's okay you'll find out.