That previous post is supposed to say "have every receipt" for services done. I would highly recommend Volvos. They have always been good to us and the friends I have that own them. They are a popular car in CA because they are cheap to buy, reliable, and not hard to fix. All of my friends fix their own stuff. Our current wagon, though 25 years old, has an inline 4 cylinder. Very easy to work on, though I have not really had to.

 

Thank's to murphy's law....those are generally some famous last words!

 

LOL Lee...so true...I might wanna retract that statement

 

Being a three post, which two did you use? Ordered mine finally the other day.

 

All three.

I'll have to check tho can't remember all the connections.

 

The posts are labeled P, S and I. Here's a picture that shows the wiring.




What you do is take a wire from the "start" wire on your starter relay (passenger side fender) and run it to the S terminal. That turns the pump on as soon as you hit the key.

The I terminal gets a wire run to a 12V source that is on when the engine is running. Most guys use the fuel bowl heater wire for this.

The P wire, gets wired to the positive side coil wire on the fuel pump relay (terminal 86 on most automotive relays).

The relay wiring is pretty easy as well. Terminal 85 goes to a good ground, 86 goes to the Oil Pressure Switch, 30 gets a fused (I think I used a 20A fuse) 12V + input, and 87 goes to the pump + terminal. Pump - gets a good clean ground. It sounds more complicated than it really is.

Here's a picture that shows the relay wiring.




The difference is that this picture doesn't show the oil pressure switch in the circuit, so it gets put in between terminal 86 and the ignition switch. Let me know if you have questions about this and I'll try and explain it better. I really should just draw up a schematic for it to make it easier for people to see it all together.

 

^^^^ That is the one I'm using also ^^^^ So far no issues.

 

Are any of you running this with the strictly diesel wiring harness? Their original switch only uses two poles. It pulls direct power from the battery to the relay using the open/close circuit of the switch. "On" signal is wired to my fuel bowl heater. Adding another wire does not seem necessary?

I only need to use the P&I terminals or P&S?

 

That approach works as well, it may just make for a bit longer crank times before the engine fires, because the pump doesn't activate until the switch sense oil pressure. The engine may actually fire without the fuel pressure, but wiring both sides of the oil pressure switch like I show above makes so that the pump comes on as soon as you hit the starter, and then when you let off the starter, the oil pressure keeps it running. This way is technically more correct, in my opinion, but that method of wiring the system will work as well.

 

The strictly diesel harness utilizes a 15 second prime with the system(relay/controller) when the key goes on, hence why I use my fuel bowl heater as my source. After 15 seconds the pump will not operate till there is oil pressure but your lines should be fairly primed to crank. That all being said I would think if I use P an I I will be just fine, as I do not need the S post in my application. I guess I can only give it a try and see.

FYI if after 8 hundred and some posts you have not read on how much of a dimwit I am with electrical, I want to bring it up again. I sure do enjoy reading diagrams and can understand it, but when I need to make this wiring loop work with another wiring loop I tend to screw it up pretty bad

 

Just use the P and I terminal on your original two wire setup. Should work fine. I too am using the starter relay for prime and so far have not had any issues starting. I like the Strictly Diesel priming setup better but already had this installed before I upgraded to Driven Diesel OBS regulated return system. Just couldn't justify another $130.

 

Appreciate it. That's what I figured.

 

Yep. Jim has you on the right track. With the prime timer in the system, the wire from the starter relay and the S wire on the pressure switch are unnecessary. I guess I didn't realize you had the timer as well. I like that design because it primes the system.

 

BTW, not sure if you know this already, but the NAPA part # is you need is 6610.

 

This one? NAPA AUTO PARTS