Protect your lift pump

[klcammie]

Thank you. Your message about wiring a relay in the circuit for the lift pump saved my ecm. Yesterday I lost fuel pressure and the auto reset breaker got so hot it stuck in the on position. I couldn't hold it in my hand. I can't imagine what this would have done to the ECM. IMHO all should wire a relay in the circuit to the lift pump. Thanks again.

Edited February 19, 2017 by klcammie

[Mopar1973Man]

Most all aftermarket fuel systems today have a trigger relay and 20 amp fuse. I would highly suggest relay and fuse protection to prevent the full load of the pump being placed on the ECM like OEM setup is. 

[RonJon]

Is there a Wiring diagram?  Where are you pulling power from ?

[Mopar1973Man]

Most folk pull power from the battery. 

 

+12V -> 20A Fuse -> Pin 30 on the Relay -> Pin 87 out to the lift pump

 

Black / White on the lift pump lead -> Pin 86 of the relay 

 

White/yellow on the lift pump lead -> Pin 85 of the relay (trigger power).

 

 

 

 

[RonJon]

• Understood.. Thank you.

[IBMobile]

2 hours ago, klcammie said:

Thank you

Your welcome, glade it helped. 

Here's that diagram for anyone else that may need it.

 

[2001cummins]

is this only for aftermarket pumps that don't use the stock wire harness. I am using an airtex in stock location and just plug the pigtail into the pump?

[dripley]

The pig tail for oe pump pulls the power thru the ECM. Hooking it up thru a relay takes the load off of the ECM. The aftermarket pumps that come with a relay and harness are designed to use the oe pigtail for a trigger wire and power comes from the battery and not thru the ECM.  That being said if you are connected to the oe pigtail straight to your pump you are pulling the power thru the ECM.

[Thunder2001]

Is the relay in your drawing a separate relay, or are those the numbers from the   Relay box under the hood?

I also have a pump made for stock location and Air Dog says to just plug and play. Maybe I will change it .

[Me78569]

relays have a standard number to show what pin.  30 87 86 85 are printed on the bottom of the pin.

 

At least I thnk thats what you are asking.

Edited February 9, 2017 by Me78569

[Thunder2001]

Thank you. I am gonna make one up asap.

[Dieselfuture]

Your airdog 150 should have came with wiring harness and the relay, and part of air dog harness plugs into truck hardness if it was updated at Dodge dealer to have a lift pump mounted to the engine instead of fuel basket. Or it might be the other way around, either way air dog and fass as far as I know both come with wiring harness with a relay included. You might just need to find a wire that comes from ECM to power that relay.

Edited February 9, 2017 by Dieselfuture

[IBMobile]

This is a typical automotive relay you can buy at any auto supply store.

Do not use pin 87a. 

I've had some relay terminals marked 1, 2, 3 and 4.

terminal 1 = 86

terminal 2 = 85

terminal 3 = 30

terminal 4 = 87

31 minutes ago, Dieselfuture said:

You might just need to find a wire that comes from ECM to power that relay.

The yellow/white wire comes from the ECM and was uses to power the stock fuel pump.  This is the wire you want to trigger the new fuel pump relay at pin 86.

[klcammie]

17 hours ago, 2001cummins said:

is this only for aftermarket pumps that don't use the stock wire harness. I am using an airtex in stock location and just plug the pigtail into the pump?

My lift pump is in the OE position. I used Ibmobile wiring.

Edited February 10, 2017 by klcammie
Correction

[SilverMoose]

I've got the FASS ddrp that uses the factory connection.  I keep thinking I should add a relay and this post confirms that.  Oil change & relay this weekend.

 

L8tr

D

[JAG1]

17 hours ago, Dieselfuture said:

Your airdog 150 should have came with wiring harness and the relay, and part of air dog harness plugs into truck hardness if it was updated at Dodge dealer to have a lift pump mounted to the engine instead of fuel basket. Or it might be the other way around, either way air dog and fass as far as I know both come with wiring harness with a relay included. You might just need to find a wire that comes from ECM to power that relay.

The Air Dog harness has the ECM plug on it just like the factory plug and set up to only activate the relay. I think FASS does also.

[2001cummins]

Sorry for the dumb questions but I will admit I am electrical challenged. the advantage to this is it takes the load off the ecm. so have many people had problems with this and this was best solution. Just trying to see what advantage this has over factory- can the factory ecm not handle the load?

 

Also where are yall mounting all this for a stock pump location on engine.?

 

I have learned a lot on this site in the last month or so and just trying to do what is best for the longevity of my truck.

Edited February 10, 2017 by 2001cummins
add

[Mopar1973Man]

Basically there is no protection relay or fuse between the lift pump and the ECM. So if for some reason the lift pump to lock up or short out the ECM would take the damage and cost upwards of $1,500 and higher to replace. So protection relay and fuse is much cheaper than losing a ECM.

[2001cummins]

19 minutes ago, Mopar1973Man said:

Basically there is no protection relay or fuse between the lift pump and the ECM. So if for some reason the lift pump to lock up or short out the ECM would take the damage and cost upwards of $1,500 and higher to replace. So protection relay and fuse is much cheaper than losing a ECM.

thank you sir, that explains good enough to me to justify doing.

one more question

So the yellow/black wire- IS this one that is on the stock pig tail color-that connects to pump?

Black/White wire- IS this one that is on the stock pig tail that connects to pump?     - These two can just be cut and then wire to relay box?

 

then 87 you have going to fuel pump. will this be just the red wire off my lift pump  and then ground the black wire on the fuel pump somewhere?

Edited February 10, 2017 by 2001cummins
edit

[Mopar1973Man]

 

Yellow/White is - Positive 12V power (ECM controlled).

Black/White is ground