Power for the P7100 and lift pump on a 99 24v swap

[cbrew]

Hi All, I have a question, 

I am in the home stretch of swapping my 24v

i am needing to tap for key on power for the lift pump and fuel shutoff, 

those that have p pump swapped their trucks, where did you tap in for key on power? 

just looking for ideas before i get to that step

 

Thanks. 

[Great work!]

There are lots of options for the lift pump power it really depends on how big the pump is that you are using. There are a lot articles about it all over the forums and the manufactures of the pumps usually have some instructions too. The green with black wire in the engine connector (near center of the firewall) is Keyed power from the 

fuse block on the side of the dash. It only has a 10 amp fuse so it will need a relay setup for a serious pump. The fuel shut down has a pull in wire and a hold wire, both require

a lot of current and have relays on the 12 valve trucks and fusible links. The pull in part is turned on momentarily by the starter wire. If left on it will destroy the shutdown solenoid.

If you are getting rid of the ECM there is going to be a whole mess of electrical issues some are not easy fixes either. Some folks rig up a choke cable to shut off the P7100

saves a lot of headaches. 

[cbrew]

Morning and thank you for the response, 

the lift pump is an Airdog 2 165 and i will be upgrading to the G4 motor and pump as part of the project, while the old motor and pump are running fine, they are pushing 7 years old and about 80k miles. so it will be replaced. that said, it has its own relay that is already drawing from the battery directly, but using the ECM to trigger the relay. 

after looking at the diagrams, this signal is triggered from the VP44 directly, likely turning the pump on fire fire-up (you know the 10 sec bump of the lift pump) 

and thinking back when the VP44 crapped out 6 years ago, the lift pump would not turn on until the reman vp44 was installed and connected. 

I picked up the harness from larry b for the solenoid i have for the p7100. while i still need to look, it has at least one relay. 

 

I already am planning on running relays to power the solenoid and lift pump, I just need a signal source that has power at run and start position.

the ECM will remain for now, I just need to figure out where i can secure it,. the p7100 is long enough to require ECM relocation, the harness does not have enough wire to relocate to the fire wall or frame rail. 

I will hunt down that wire you called out. 

I will also probe the vp44 harness, 

 

Worst case, I can run a simple hot wire but i know that is the last resort. 

[Great work!]

Typically on the diesels the red/white wire is always hot and the green/black is hot when ignition is on. The start wire run down the same tube as the +battery cable to the starter.