lezmark7

I dont seem to be getting power to the pump, yet I cant find any blown fuses... maybe if someone can help me out by telling me exactly which one it is? Thanks.

thumper549

"seem" what does that mean ? Have you tested the wire to see if voltage is there (test LT ) ??

lezmark7

I just have a 12 v test light...

thumper549

That's all you need, Grd one end as usual unplug the L.P. check for voltage . I think the white one is PWR ..but it does not mater you know you need Pwr at one of them and of course the other is GRD

mishkaya

I believe you have a relay for the pump in the under hood junction block. You can swap it with the Horn relay to see if that's the problem.

lezmark7

I have already done that and there is no juice - that is why I am hoping someone can tell me where the fuse location is, because I cant find it... that has to be the next thing to check...

thumper549

You swapped relays ?

mishkaya

I could be wrong as it has been a while since I have had to mess with that stuff, but I thought the relay was triggered by the ECM, and that it does not have a relay. If you have swapped relays with the horn relay and it didn't help, but the horn still worked afterwords that would tell me that the ECM doesn't think the ignition is on. There are a few things to check in addition to the grounds, and those are the Cam position sensor, and I think on your truck, the Crank position sensor. If either of those do not work properly the truck will not start.

thumper549

One has to confirm there is no voltage 1st...as these pumps burn out on a reg. basis
so..get your test LT out and see if you have voltage , or not.

lezmark7

I have no voltage - and no I havent switched relays. I wouldnt know how to do that. I just kinda figured there must be a fuse and that would be the next thing to check...

littlebuddie

Open the hood and look for the Power Distribution Box. Remove the lid and note the relay and fuse locations on the inside of the lid. Swap the horn relay with the pump relay. If you are careful, you can do this without disconnecting the batteries and shorting out the system. Try honking your horn. If it honks, the pump relay was good. They are identical relays.

littlebuddie

I forgot to mention that after you remove the pump relay, you might set a code that indicates 1689, or problem with the injection pump. However, your truck may have already thrown that code if there is a problem going on with the pump. Do you have access to a code reader?

lezmark7

First THANKS for taking the time to help out! I tried switching relays (learned something!) the horn worked before and after switching. I dont have a code reader but did the ol switching the key and got a 1693 code... retested with my test light - still no juice...

mishkaya

I am not sure which pump you are looking for power on, is it the lift pump, or the injection pump? If it's the lift pump, you won't have any with the ignition on as the pump only runs for a few seconds. You would need someone to bump the starter, then you will have about 20 secs to check for power. Or are you checking the VP44 for power?

lezmark7

I have a Fass pump that used the stock lift pump harness, so there is no lift pump per se. The truck will start and run. It is the wiring to the Fass pump that has lost power. Nothing has been touched or worked on lately and the setup has worked flawless for the past couple years. Normally as soon as I turn the key, i can hear the pump.