Well I went to the cabin with the truck this last week. It's at 9800 ft and was getting below freezing over night. So I started it each day and used it. But today I start it, load up the at, no issues. Let it sit for a while. Decided to check the oil since it's a 200 mile drive home, it was fine. Start it up and start to leave, and I notice my battery light is on. So I got out to check the connections, no issues there. The voltmeter is at the N on normal. So I figure no since in wasting time, since the nearest town in 45 miles out if I had issues. Start driving, and the voltmeter did not go up at all with rpm. Slowly the gauge made it all the way to the M in normal, which is near where it normally is. I have made it home now. What would cause this? Bad battery, where the other was enough to run the truck, and the uncharged one started charging as I was driving?

Thanks. Matt

 

That would be my first check, get a load tester and check them both, also check the wires going into the alternator as well, there easily bent when working on the fuel system and become dislodged.....

 

Well.... here is what I did...

Went out there with the multimeter... checked both batteries. Both read about 13 Vs, so we dont have an issue there. So I turn the glow plugs on to see if there is any major varaiance between the two batteries when they have a major current draw on them. Both read around 11.5V when the glow plugs are burning. So I start the truck. And both battires are around 13.5 V when running, where as before, I believe they were more around 14.5-15V.

I dont know if that is how a load tester works, but since the amperage draw that would be going on would show the weaker battery really quick, I think it worked.

I also checked all the connections into the alternator. I wish I had a high amperage Multimeter, so then I could see what type of amps is coming out of the alternator.

Here is how the gauge reads on the dash now.



It does not go up with RPM at all. I have a brand new belt on the truck (less than 1000 miles). So now im thinking it might be my alternator. any ideas?

Thanks guys! I need this truck to be in tip top running shape! I am planning on doing new Glow Plugs since I have a few bad, and i have a California truck, so it has a CEL for them. I also plan on new injector O rings, or possibly stage 1 injectors this summer. This is my Daily Driver/ tow vehicle/toy.... right now I really dont have much choice but to get this one fixed.

 

Took the atlernator off... took it to get it tested. and guess what. It was a bad alternator. Swap it on, and its running great!

Glad I got that fixed... now next on the list is the fuel tank leak.

 

Glad you got er fixed!! That pic of the gauge is how mine sits when the GP's are warming up and then goes to the middle after 2 minutes.....

 

Mine does that too yoslick. I never noticed it until I changed the Alternator. My mechanic thinks there may be a problem with my glowplugs making the gauge read like that. Everything seems to work fine after 1-2 minutes so I am leaving it alone.

 

Yeah that was after 5-6 minutes of idling, where the glow plugs would have turned off. I also fixed my door handle inside where I can use it to open the door rather than roll the window down and open from the out side.

 

Thats normal for 2 minutes of GP operation, it's a wonder the smaller wires going to the GP's can handle all that juice and not melt after about the 50th time!! Oh was gonna ask what amperage did you replace it with? DB on ebay has some real nice 200 amp units that really put out the juice!!

Slick

 

I just put a stock replacement 130 Amp on it...

 

FYI. In order to check the batteries they must be disconnected from each other to get an accurate volt reading. If they are connected and one is bad, you most likely won't be able to tell which one. They must be tested independently.

 

Neal, that is a very valid point. I should have thought of that... guess too late. The alternator was a lucky guess.

 

Mine does the same thing for a couple minutes. I just had glow plugs replaced a few months ago, (along with 150cc injectors) and did not notice any difference in the gauge.