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So this started the other night plowing. I noticed my voltage on my tuner was reading 11.5. I put in a alternator back in the spring. I was like great, another dud. Later on in the night it got back up to 13.5+-. ended up dropping back down to 11+-.
I bought a new 140 amp alt. installed it, still not charging properly. At the 2 wire connector I’m getting 11 (or whatever the batteries arvolts on one pin with KOEO. At first, the other one I get zero volts no matter what.

I researched a bit and saw that if possibly the glow plug relay were bad causing them to stay on, the PCM would not tell the alt to charge. so thinking that I disconnected the GPR

I then saw 11+- volts (again, whatever the batteries read) on both of those 2 pins on the alt connector.
I started the truck and the volts went up to 13, than 13.5 and most I saw was 13.8. So I said sweet, I must have a bad GPR.

wrong. It’s an intermittent connection somewhere on the “charging” side because i now have 10.8 volts to 11.5 volts running.
I have no idea where to look or what to check next. I have good connection on all terminals. I have connection on the red cable on the back of the alternator. I’m completely lost
 

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So you have a 2005, does it have a single or dual alternator? Assuming single.

At any time did the "battery" light come on the cluster? It's doesn't mean battery; it means the battery is not charging.

Attached is the diagram; as you probably already know, the three-pin connector, one side is the "Sense" wire, telling the voltage regulator what the battery voltage is; the other "I" circuit is from the cluster telling it to turn on. Key-on, it should be battery voltage, which you say it is.

First, I'd be really checking if the three-pin connector is fully engaged and recheck the sockets to make sure one has not backed out of the shell.

771684
 

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So you have a 2005, does it have a single or dual alternator? Assuming single.

At any time did the "battery" light come on the cluster? It's doesn't mean battery; it means the battery is not charging.

Attached is the diagram; as you probably already know, the three-pin connector, one side is the "Sense" wire, telling the voltage regulator what the battery voltage is; the other "I" circuit is from the cluster telling it to turn on. Key-on, it should be battery voltage, which you say it is.

First, I'd be really checking if the three-pin connector is fully engaged and recheck the sockets to make sure one has not backed out of the shell.

View attachment 771684
The battery light has not come on at all whatsoever during this whole fiasco.I have triple checked everything and I must be missing something. I’m lost here. I checked grounds I checked my cables. The 3 pin connector is engaging all the way from what I can tell
 

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With the engine off, connect a jumper (should be fused) to the I pin with the connector off the alternator. Turn the key on and see if the battery light is illuminated.

If it's not, it's cluster and supply hunting time.

I'll give you the pdf for the cluster of a 2003. Pinpoint Test O.
 

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Discussion Starter #5
With the engine off, connect a jumper (should be fused) to the I pin with the connector off the alternator. Turn the key on and see if the battery light is illuminated.

If it's not, it's cluster and supply hunting time.

I'll give you the pdf for the cluster of a 2003. Pinpoint Test O.
I actually have my old cluster that was originally in my truck... I bought a KR cluster on eBay that I swapped into my truck with the same mileage. I already tried swapping clusters and nothing changes. The light still does not come on whatsoever on either cluster. Even adding a jumper. I rechecked my regulator connector, now I don’t have any voltage on my “I” pin with the key on. I know it did earlier. I even cut the insulator back behind the connector to try it there. So part of me is thinking voltage isn’t being transferred from the alternator to the batteries. OR I have some kind of issue going from the connector to my cluster. I tried hooking a battery cable from the terminal on the starter straight to the battery post, which did not make a difference either.
 

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Is the 10a fuse feeding the cluster OK? Even if it looks good, I'd flip in another. Position 45 on a 2003. 2005???
 

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Is the 10a fuse feeding the cluster OK? Even if it looks good, I'd flip in another. Position 45 on a 2003. 2005???
it’s a 2005 and I’m pretty sure that fuse is good. I’ll recheck and throw another in. At this point I ripped out both batteries and trays and I’ve followed every wiring harness I could find and I don’t see any damage to any wiring whatsoever. Surprisingly all my harnesses look fine... no bad wires, no cut insulators, no corrosion anywhere.
I have a plow setup too and all my plow wiring looks fine.

I’m at a loss. I really don’t have the cash at the moment to send it to a shop especially with diag time but I’m literally lost here. My buddies who are familiar with this crap aren’t answering me either.😒

I have continuity between all cables. I have continuity from ground cables to frame. I have continuity from pos to alternator. I really think the issue has to do with that “I” wire on that circuit... Im Not familiar reading electrical diagrams and that’s why I wanted my buddy to help me out. Either way I’ve been working on this thing all day with no luck with anything
 

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I didn't think you had any cable issues except with the possibility of the sense, but mostly concerned about the I circuit. If for some reason, the fusible links blew, there would be an issue of continuity between the large post on the alternator and the battery terminal connection, so the alternator charge would not get to the batteries. That test is the voltage at the alternator should be the same as the voltage at the battery.

You could move them around and see if there is an intermittent contact, the same with the sense. The I circuit again is what turns the alternator on. On occasion, the connections in the shell become bad. But that is an easy test, battery voltage with key on, and sometimes running and wiggling the wires into the connector show an on and off engagement.

Unless it's a bad alternator ...... again, I never discount that from parts stores, and they do a poor job of testing them.

771691
 
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