So I got the normal 3 gauge pillar from Clay at Riff Raff, and it has the indicator light built into the pillar. I am noticing that the light does not always come one now, and when the light does not come on the truck will not start.
Do you think it is the Glow plug relay that is not functioning properly? Something else? If I need a new one is it hard to replace? Just get a stock one or are there aftermarket ones that are better?

Thanks

 

Double check to make sure that you don't have a loose connection, and verify at the GPR terminal. If you are having issues it is a 10 min swap.

Riffraff Diesel: OEM Glow Plug Relay

 

Sounds like intermittent operation of the GPR or the GPR contacts are pitted. Have someone cycle the key while you check the GPR output terminal 4 for voltage and also feel or listen for it to operate. If it is intermittent operation or intermittent contact closure it needs to be replaced.



You can also swap the AIH relay with the GPR and see if the GPR LED indicator always comes on. Be careful with any loose wires if you do this.

Some go with a larger Stancor contactor relay. See this link : Welcome to guzzle's Stancor GPR replacement Mod Web Page

My Stancor Install.

EDIT: Clay's has a damn good price for OEM GPR. MSRP is about 80 bucks. And I am very slow.

 

Take a look at this video. It will help you troubleshoot your GPR. Also understand the GPR does not come on with the oil temperature above 131 degrees. If your truck is warm the GPR will not be commanded on, you will still see a WTS indicator though.

GPR operation - YouTube

 

From the Ford service manual:

 

Could I just use the aih relay instead of the glow plug relay? I am not using the AIH relay, atleast I dont think so, I think I have the riff raff aih delte thing. Are they the same relay?

 

Yes you can. Just be sure you protect the wiring you dsconnect from the AIH relay. Best thing is to shrink wrap the individual connectors and then bundle them up out of the way. You don't want them shorting to each other or anything else.

You will get a soft codes because the PCM will not be able to see the AIH relay. The codes will not light the CEL.

The codes will be P0541 Intake Air Heater Circuit A Low and P0640 Intake Air Heater Control Circuit.

 

OK, thanks for the answer. So I plan on moving over the Aih relay to the glow plug relay position and moving the glow plug relay over to the aih relay positon. Does that make sense? I know I should shrink wrap everything that is unprotected. thanks again.
This can be a permanent change? Should I unplug the batteries?

 

If the GPR is no good why move it or even keep it? If it is bad it may not keep you from getting the codes.

It can be permanent until the AIH relay fails. No saying how long it will last. I don't think it is as robust as a GPR. You could just get a Napa GPR109 for about 25 bucks and not fool with the AIH relay. A Stancor 586-902 would be best but it doesn't sound like you want to go that route.

I usualy just lift the positive cables. One post of the GPR and the AIH is always HOT. You don't want to get all sparky.

 

I guess I thought they were exact copies of each other. If that is not the case then I will go a better route. Is the Stancor that much better? It is not a direct bolt on swap out though is it? It looks like it mounts different though

 

It's easy to install horizontally. More work to mount vertically as in my install.

The Stancor is about fifty bucks. . I got mine from onlinecomponents.com It says White-Rodgers 586-902 but it is the same. I see they have gone up about ten bucks sense I bought mine.

Do a search for 586-902 and you may find a lower price but then shipping charges vary and you have to take that into consideration.

 

I wonder why the AIH is almost twice as big as the glow plug relay if it is not as good of a glow plugrelay? What amp are both of them?

 

Subscribing. I think this happened to me the other day.

 

All I can say is that it wasn't designed to be a GPR, but may work just fine.

Another member has used the AIH as a replacement for the GPR for years, although he has wired in manual control so he only operates it when he feels the need to.