M1009 electrical problem

[kdaniels]

I have a stock (unmodified) M1009. Truck has been flawless until the amp gauge stopped working. Vehicle will cycle thru glow plug warm up as normal and the alt lights go on and off as normal. So i figured bad gauge and put it on the list of things to do.

Went out to start the truck a week or so later and had no power to the ignition switch. Checked the bats and found #1 to be dead.

Charged #1 and the truck started right up. However when i shut it down one of the alt lights comes on so i've had to pull bat cables to keep from draining battery.


A check of voltage going to the bats while truck is running gave a 14 ?? some thing volt reading to #2 bat and a 12 ??? something volt reading to #1. (cant remember exactly) Doesnt seem like #1 alt is charging.....but i have no clue if this is tied to the amp gauge problem or not....


Any Ideas ??? Thanks in advance for any info.



SEMPER FI

keith

 

[1stSarge]

Normally, what I always think, is, that if two electrical malfunctions happen at the same time, they are related. But in this case I’m not sure.

The voltmeter has its own relay, look for broken, dirty, or loose connections there, as well as on the back of the voltmeter.

It does sound like your alt 1 is bad, I would have it tested. One quick test if you are up for this sort of thing, is to test the diode trio inside the alt, and the rectifier bridge. Those, along with the voltage regulator are what normally go bad.

14V+ is normal for a charging alternator.

Take a look at the links in my signature, the picture is from one of warthogs posts.

 

[JAsher45]

i agree sounds like a bat alt #1

 

[kdaniels]

#1 alt tested...shop found it to be bad. $140 for a rebuild and she is charging the battery @ 14v. I pulled the dash out to check Voltmeter and bumped it on side of metal dash, i got a small spark so i know i got power to gauge. Blew the 10 amp fuse also...

Located a used gauge and i will put it in tomorrow when i got more day light. Hoping this will be the end of my electrical problem.



THANKS for the info !!


keith

 

[1stSarge]

Thanks for the follow up Keith, let us know if the new voltmeter fixes the problem. Yeah, I’ve replaced that fuse a … few … times.