Charging problems

cumminspower09

New member
Joined
Dec 16, 2007
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50
Ok so I put a TPS on my truck last year. THis week it started acting up again but I found out it's acting up due to the truck not charging like it should. I took the alternater off and had it rebuilt, put it back on and still the exact same thing. As soon as I fire the truck up it stays around 10 volts and fluctuates up and down. You can volt check it and see that it will charge, then kick off, charge, kick off, and so on. Help...is this some type of voltage regulator in the computer or what's goin on?? THanks for any input

-Ben:bang
 
Two things I can think of, the charge circuit in the PCM could be on the way out or the battery temp sensor could be wonky.


Sounds like you need to get the truck hooked to a good scan tool and see what ya' get from there.
 
Sounds Like a short to me...

One of the biggest problem areas and is often overlooked is the battery cable that runs down to the starter and is attached to the oil pan.It is well known for shorting out and causing problems like this.Where it is attached to the oil pan at it always fails and will cause a short and for some reason its more prevelant on the 24v trucks than the older 12v trucks.It may be something you will want to look at and rule out.......Andy
 
The kick off and on stuff sounds like the grid heaters clicking on and off. Maybe those relays have gone bad.
 
I will check the starter wire out..by the way, which side is the starter on?? Also is there any way to disconnect the grid heaters to find out if that's the problem??
 
Starter is on the drivers side of the truck.If you follow the one positive battery cable it will run off the battery and down to the oil pan and then to the starter.its where it attaches to the pan at where it will short and arc.

The grid heater relays are located on the driver side on the inner fenderwell down between the battery and the shock tower.Simply using a wrench carefully you can take the main wire off that goes to the intake and disconnect it......
 
Ok...so here's what I found out. I disconnected the relays, started the truck and it was charging fine...everything normal. So I connect the relays back up and it's still charging normal, drive it for a little while that the charging gets screwy again. So how do I figure out if it is the actual relays or if it is a temp sensor telling the heaters to kick on?? Another question...does the IAT tell the block heaters when to come on or is there another sonsor for that?? I think I am getting somewhere as far as diagnosin the prob..but I'm not there yet
 
No, That's my next step though. I have a feelin it is my IAT sensor because the truck won't ever high idle in the morn when its cold...
 
Check the wires off the back of the alternator that go to the PCM. It is the pair in the two prong plug. Make sure they aren't shorting together. Your alternator is either bad and won't charge, your PCM won't tell it to charge because it is bad, or it is telling it not to charge due to a sensor. Here's a diagram from the 01 manual. PCM connection is in the lower left corner.

Never mind. I just read the rest of the posts. Duh :bang
 

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haha...we'll overlook that last post 4x4. Afterall it is toward the end of the day and tax season too...but thanks for the concern :cheer:
 
Ya. Sorry. I was tryin' to hurry 'cause the wife was pickin' me up and I failed to read all the posts. Then I read them and when I went to delete the post she pulled up. My bad. AIT is cheap, try it. I bought one at NAPA. Good luck.
 
4x4dually said:
Ya. Sorry. I was tryin' to hurry 'cause the wife was pickin' me up and I failed to read all the posts. Then I read them and when I went to delete the post she pulled up. My bad. AIT is cheap, try it. I bought one at NAPA. Good luck.

A TS5041 by any chance? :D
 
I'm gettin the sensor this week to try it. I unhooked the relays after the truck had warmed up and it charges good with no engine light coming on. but it will still idle real high sometimes...???
 
Just lately I have found broken wires that have vibrated them selves to death at GEN SOURCE and FIELD connection at the alternator . And it is right at the plug so the only way to tell is to do a continuity test on the connection side and about one insh up the wires .

Funny thing is that the wire breaks internally and you can't tell visually.

Check this two wire connection first with a meter.
 
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