Road1
Active Member
- Joined
- September 27, 2022
- Messages
- 62
- Reaction score
- 17
- City, State
- Sparks, NV
- Year, Model & Trim Level
- 2016 FPIU
2017 FPIU
I've spent the last couple of weeks trying to chase down a charging system problem. I was just about to start the process of pulling the alternator, and have ordered a replacement regulator and brush set, and was thinking that I might want to pick up a used PCM, just in case, so was posting for information about programming those..
Then boominXplorer saw that thread and remembered my thread about charging problems, and sais "Seen this a few times and most the time it's a weak belt tensioner. It gets stiff and won't spring back to tension the belt on the alt. Usually the ac will still work just because of the way the belt is routed."
I had replaced the belt, and the tensioner felt okay, but I figured what the heck . . .started the engine tension on the belt and the alternator started alternatoring!
Looking back, I realize that I had ignored a sign of hopping pulley -- there was a little puff of fiber out the side of the belt that I took off. This indicates a little bit of crack-the-whip action, but I had figured that this was just an aging belt giving early warning before complete failure.
Weeks with the FPIU out of service while playing outside in freezing weather (my nose is froze, my toes are froze) with VOM, new connectors and increasing fear of hundreds of dollars in failed alternator and/or PCM, about $100 in parts (a couple of connectors, the regulator and brush kit), and it turns out to be a simple mechanical problem.
So, the two morals of this story are:
First, if you're tourbleshooting a charging system problem, remember that the first point in the charging system is NOT the alternator, it is the BELT. CHECK THE TENSIONER. Even with the alternator pulley spinning like a good thing, it might be slipping -- even with a new belt -- enough to not be producing power.
And second, don't be shy about a problem, post messages here and then pay attention to what you get for responses, even if you think it won't apply.
Thanks to everyone who did respond to my threads on this. I hope that someone in the future, facing the same problem, is led to this message and saves all of the time and trouble that I had to go through.
Then boominXplorer saw that thread and remembered my thread about charging problems, and sais "Seen this a few times and most the time it's a weak belt tensioner. It gets stiff and won't spring back to tension the belt on the alt. Usually the ac will still work just because of the way the belt is routed."
I had replaced the belt, and the tensioner felt okay, but I figured what the heck . . .started the engine tension on the belt and the alternator started alternatoring!
Looking back, I realize that I had ignored a sign of hopping pulley -- there was a little puff of fiber out the side of the belt that I took off. This indicates a little bit of crack-the-whip action, but I had figured that this was just an aging belt giving early warning before complete failure.
Weeks with the FPIU out of service while playing outside in freezing weather (my nose is froze, my toes are froze) with VOM, new connectors and increasing fear of hundreds of dollars in failed alternator and/or PCM, about $100 in parts (a couple of connectors, the regulator and brush kit), and it turns out to be a simple mechanical problem.
So, the two morals of this story are:
First, if you're tourbleshooting a charging system problem, remember that the first point in the charging system is NOT the alternator, it is the BELT. CHECK THE TENSIONER. Even with the alternator pulley spinning like a good thing, it might be slipping -- even with a new belt -- enough to not be producing power.
And second, don't be shy about a problem, post messages here and then pay attention to what you get for responses, even if you think it won't apply.
Thanks to everyone who did respond to my threads on this. I hope that someone in the future, facing the same problem, is led to this message and saves all of the time and trouble that I had to go through.
