Ok I have a 2002 f350 7.3 powerstroke it will not start unless i jumper the posts on the aih relay don't know why any help would be appreciated thank you

 

No expert in any way, but the IAH seems to work with the GPR, they are mounted next to each other and I think they are jumpered to each other already, right? Could the jumper wire be bad? or the could the GPR be bad and you are providing power to it when you jump it? here's another link that talks a little about it, maybe it'll help.
https://www.ford-trucks.com/forums/1...ih-assist.html

 

I replaced the gpr it will run while I have a jumper on the aih relay but when I take jumper off it will die like it loses fuel. Every one else I talk to says you can take it off and run with out it that it don't have anything to do with starting or running so why will it start and run while I have a jumper on it and dies when I take it off I'm at a loss

 

Ok so here is what's new I've changed gpr changefuel pump relay and computer power relay and still no start unless i jumper the posts on the aih relay and when I do the fuel pump kicks on the gpr will kick on and work and it will start and run as long as the jumper is on the aih relay but as soon as I take it off it runs I don't understand why it's doing that any help please I need it

 

I thought I posted this already but dont,see it on here so here goes again. The same thing happened to me my brother was supposed to jumper the posts on my gpr but mistaking the aih relay for gpr relay jumped the wrong one and after he did that it would just keep turning over not even trying to start and wts light wouldn't go off so after messing around with it I figured out that jumpering the opposite posts he did I could here the gpr relay work and the fuel pump would kick on and the truck would start and idle as long as the jumper was on the aih relay post but when I would take it off it would die really weird because I didn't think the aih relay had anything to do with any of that especially the fuel pump still haven't figured it out yet so if you do find anything out let us know because it's probably the same problem good luck to you and if I figure it out I'll post so maybe it will help you as,well

 

Or you could choose the proper course and start your own thread instead of bumping a two year old thread to post your own problem.

Stewart

 

well I did start my own thread but not getting much response and found this one and it was almost exactly the same thing that happend to me so I tried to maybe get a response just grasping at straws didn't realize it was a old thread sorry if it bothers you I'm new to this forum and didn't know how to delete it

 

Like I said, no expert here, but if it were me, I'd be starting with checking and cleaning all ground wires, recheck voltage on out going side of GPR, could be a NEW BAD GPR. Check battery condition, make sure they're up full charge. There is also a sensor (EOT) mentioned in the article link, you may want to check that. Oh yeah, I found a link for you to read that may be helpful...LOL

GPR and AIH Relay Help if you can please - Diesel Forum - TheDieselStop.com

 

I found your thread. You didn't post it in the proper forum so I moved it here.

I also cut the posts you made in the old thread and moved them to your AIH thread that is now here in the 7.3L forum.

Stewart

PS - It doesn't "bother" me, it's just proper forum etiquette. Never bump an old thread unless you have additional info that adds to the tech in the thread, and is beneficial for anyone that may come across it for help. It's never ok to add your problem to someone else's thread (problem) because you detract from them getting help.

Always start your own thread when you have a problem with your truck so the answers will be directed at helping you.

I'm sure you wouldn't want someone to come to your "I need help thread" and hijack it for their own problem, right?

 

Ok, posts cut from the old thread and moved to this thread, so for anyone reading, that explains the goofiness of the posts above and how they may not make sense untill you realize posts were cut from one thread and merged this one.

Stewart

 

Thank you mike1 I have made sure to keep batteries at full charge since I have been working on them and as far as the new gpr when I check it its getting power to all 4 posts with or without key on but doesn't buzz or anything unless I cross over the power post and one of the little post on the aih relay and when I do that the glow plug relay will buzz and fuel pump will kick on and truck will start and run until late I take jumper off of aih relay then truck will die because it loses fuel. And I will check the eot sensor thank you aging for the help you don't know how much I appreciate it

 

If I am reading correctly you are saying that all four posts on the GPR have power to them. Only one large one should have power all the time, one small one when the key is on and it usually is on the side facing the front of the truck. The little one facing the firewall leads to the PCM and is a ground wire that the PCM grounds when glow plugs are called for. When that happens, then the other large post should get power. You should not have power to that rearward post on the GPR, EVER.

 

Yeah that's exactly right on all 4 posts don't understand it either don't know why it's doing it and don't know if I mentioned it or not but my wait to start light stays on and I know that's not a good thing

 

Are you getting any DTC codes? Suscribed.
Ed

 

Someone with more technical knowledge should come along. If it was me I would disconnect that wire from the GPR to the PCM ground and test it for ohms to ground with the key off. You should get no reading.