CEL bonanza
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From: Southern New Mexico
CEL bonanza
So, I had some issues with my battery terminal clamps just not being very secure anymore, so I decided to replace all my battery cables (positive and negative). Kind of a PITA, but nothing too bad. Since then, I've hit the motherload of glow plug related CELs, one for each glow plug, P0671 through P0678.
I've never had any glow plug issues, let alone 8 glow plug issues, so no doubt I'm at fault for having forgotten to reconnect a power cable for the GPCM. Where does the GPCM get its 12V from? Is it at the starter relay? I thought I was diligent in paying attention to every cable I disconnected so that I'd know where it went when reconnecting, but spacing the project out over two weekends clearly didn't help. Yes, I'm an idiot.
thanks,
Herb
I've never had any glow plug issues, let alone 8 glow plug issues, so no doubt I'm at fault for having forgotten to reconnect a power cable for the GPCM. Where does the GPCM get its 12V from? Is it at the starter relay? I thought I was diligent in paying attention to every cable I disconnected so that I'd know where it went when reconnecting, but spacing the project out over two weekends clearly didn't help. Yes, I'm an idiot.
thanks,
Herb
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From: St Louis
California or non-California emissions? Check sticker underside of hood. There are significant differences in the glow plug control circuits between the two. California uses the module while non-California uses a simper relay.
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herb
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From: St Louis
Okay, I seem to recall hearing that before. I'm just going off the documentation in the EVTM and it shows two variants.
Don't know if it's mechanically possible (the connectors look to be physically the same in the EVTM), but can one hook the two connectors to the GPCM backwards?
Don't know if it's mechanically possible (the connectors look to be physically the same in the EVTM), but can one hook the two connectors to the GPCM backwards?
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Cross-Country
Joined: Jun 2011
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From: Southern New Mexico
Okay, I seem to recall hearing that before. I'm just going off the documentation in the EVTM and it shows two variants.
Don't know if it's mechanically possible (the connectors look to be physically the same in the EVTM), but can one hook the two connectors to the GPCM backwards?
Don't know if it's mechanically possible (the connectors look to be physically the same in the EVTM), but can one hook the two connectors to the GPCM backwards?
Herb
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I was researching what people have done for upgraded battery cables and I ran across a thread referencing something hooked up for diesels. I didn't bookmark the thread because mine is gas. But, the guy had another cable that I didn't have to the top of the engine for the pump or glow plugs. Hope that helps.....
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From: St Louis
Did you hook all the smaller wires back up to the correct terminal on the starter relay, assuming you replaced that cable to the battery(ies)? Two of those wires are fuse links that feed the ALWAYS HOT power to the GPCM on pin 3 of both of the GPCM connectors.
That's the only connection I can see that might logically have been disturbed during a battery cable replacement.
That's the only connection I can see that might logically have been disturbed during a battery cable replacement.
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From: St Louis
Well, all of the "little" wires (except the one that goes to the S terminal) have to go on the same post with the big red one that goes to the battery(ies). If any of them are on the relay stud with the other big wire that goes to the starter, then they're in the wrong spot and would only get power while cranking.
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From: Western AR
The GPCM is in the middle of the B+ wire that runs from the back of the alternator over to the relay on the fender. There is a tap off that 8 gauge wire to feed the GPCM. So, it gets power from the batteries when the truck is off, and the alternator takes over from the other side when the engine is running. The B+ wire comes off the alternator and joins the main engine harness going across the top of the engine, then pops out of the harness over the passenger side valve cover.
I agree with SHO...you hooked up the wires on the starter relay wrong most likely.
I agree with SHO...you hooked up the wires on the starter relay wrong most likely.
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From: Southern New Mexico
Did you hook all the smaller wires back up to the correct terminal on the starter relay, assuming you replaced that cable to the battery(ies)? Two of those wires are fuse links that feed the ALWAYS HOT power to the GPCM on pin 3 of both of the GPCM connectors.
That's the only connection I can see that might logically have been disturbed during a battery cable replacement.
That's the only connection I can see that might logically have been disturbed during a battery cable replacement.
Herb
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