Not charging, no code

[Figor]

Hi guys.
I noticed my brights were dim last night so I look at the gauge and it’s sitting at 10 volts.
This morning I put a meter on it while it’s running and it shows 11.98 high idle. I let it warm up so the grid isn’t cycling. Still 11.98.
I cleaned all the battery and crossover connectors to bare metal and put some dielectric grease on them. Still 11.98. Im not getting any codes. If the alternator went south wouldn’t it throw a code.
Btw. It’s a 2005 6 speed 4x4. I had to put a rebuilt ecu in it about a year ago. Been running great until this. Any help is appreciated.

 

[Smoke Eater]

Usually your alternator should be charging at around 14.5 volts or so. The voltage is controlled by the PCM if I recall correctly. I've replaced mine on my 04 once, never threw a code that I recall.

 

[Figor]

Usually your alternator should be charging at around 14.5 volts or so. The voltage is controlled by the PCM if I recall correctly. I've replaced mine on my 04 once, never threw a code that I recall.

Replaced pcm or alternator? I had to replace pcm last Feb.

 

[Ozymandias]

Check with a decent software the ECM for command and return numbers of the charging system.
If you can't do this - stop right here and let a dealer check that.

You NEED to know these numbers before you can proceed.

 

[Smoke Eater]

Replaced pcm or alternator? I had to replace pcm last Feb.

Alternator, pulled it and had it tested.

 

[GCroyle]

I had my 2005 alternator fail 2 yrs ago. Pulled and tested good. But what seemed to be was it got jostled just enough to make the brushes make sorta contact to the slip rings while tested but not in truck. IIRC not difficult to pull brush assy and look at slip rings. One of mine was deeply worn thru.

 

[Darkbloodmon]

Usually your alternator should be charging at around 14.5 volts or so. The voltage is controlled by the PCM if I recall correctly. I've replaced mine on my 04 once, never threw a code that I recall.

My 03 6 speed didn't throw a code for an alternator, you only have the battery charge light in the gauge cluster but the threshold between noticing the problem and it lighting up on your dash is quite wide.

Test the alternator and verify battery health.

 

[Figor]

Ok thanks. I’ll pull the alternator and have it tested or maybe just buy a new one. I’m not sure the people at the big box parts stores we have around here really know how to test them. I guess I was confused as to why there was no code. I now see the threshold is kind of wide for that to happen. I was worried the pcm was bad again.

 

[Figor]

I had the alternator tested at NAPA today. It was bad. Got a new one and I’ll install it in the morning. Hopefully that’s all it is. I’m pretty paranoid about ecu’s ever since it failed last year. The ecu on my motorcycle failed last fall. I’m not an ecu fan.

 

[AH64ID]

No code when the brushes wore out on my 05’s alternator. It was caused by weak batteries. I had the alternator rebuilt and put new batteries in.

 

[Figor]

I don’t think there’s anywhere left around here that rebuilds them. I just went ahead and bought the Napa one. They said lifetime warranty. I doubt it had the original in it at 280,000 miles.

I believe the batteries are still good. I didn’t have any in my 97 so I put these in and it fired it right up and has been starting easily the last two days. It was in the 20’s yesterday and no issues with the batteries. I had to crank them quite a while and reheat the grids a few times last night. The old 97 needs new fuel lines among other stuff. The batteries didn’t weaken.