Gen 1 light stays on but REAR battery not charging?

[a175]

Even with searching and reading, I am confused by this. My understanding is that the rear battery is charged by Gen 2 (passenger side) and the front battery is charged by Gen 1 (driver side). Did I get this mixed up?

My rear battery is not charging while the M1008 is running. I can plug it up with a battery charger and that is fine, but I'm sure eventually that won't work anymore. Also, my roadside service provider knows me too well.

My front battery is just fine. I replaced both batteries several months ago. In the last week or so I've had to recharge the rear battery twice just to get it started. It runs and cranks fine for awhile... then the next time I try to start it just won't get enough juice. My voltage gauge never gets better than right where the yellow and green sections meet. It usually hovers around the middle of the yellow.

Now, I suppose it's possible that maybe the Gen 2 light doesn't work and maybe THAT'S why it doesn't come on... but why would the Gen 1 light stay on all the time? It doesn't change as far as brightness, but as long as the truck is running it shines.

Battery testers show the front battery charging just fine, but nothing going on at the rear. I haven't tested my alternators yet because I really don't comprehend how it's done. I also have a slight aversion to messing with sparky things due to a family tragedy.

I know the easy answer is to take it to an alternator shop or a mechanic (oldmechanic I think this takes priority over my wobble issue?) and let them fiddle with it. But I just want to understand why this seems so backwards to me.

Thoughts?

 

[Skinny]

Thoughts...buy a voltmeter...read the stickies...study the diagrams.

It isn't too hard to diagnose the charging system and won't cost more than $100 for you to rebuild both alternators and replace both drivebelts either. You need to go through it one step at a time. Remove the GEN bulbs, clean the contacts, install new bulbs, check for proper voltage at the alternators, etc. It takes time and patients. Whatever you do, don't pay someone to fix it that doesn't understand it. All that will do is empty your wallet, end up with a CUCV with more problems, and still not have the charging system working.

 

[a175]

I was just reading about cleaning up things in the instrument cluster. I'm going to guess that once that happens it the Gen 2 light might come on. And maybe the Gen 1 light will chill out. Kind of a V8/Homer Simpson moment there.

 

[M1008driver]

You can clean up everything alternator/barberry related under your hood and it will and may do some good. I got a kit from CUCV Electric and had my alt rebuilt. I was going to myself, but now I'm glad I paid someone. It cost $60 an alt at Battery Warehouse and was well worth it IMHO. I do recommend the rebuild route instead of buying a new alt. Peace!

 

[Warthog]

Just a heads up. CUCV Electric has temp stopped selling products. Website is still there for diagrams, help guides, etc. Just no sales at this time.

 

[Warthog]

a175, read Barrman's Alternator help thread.

http://www.steelsoldiers.com/showth...mptoms-diagnosis-and-fix&highlight=alternator.

Things to check:

1. bottom fuse - 24v fuse for voltmeter, GEN2
2. GEN2 bulb - must be working for GEN2 to energize
3. two terminal alternator plug - must be clean and tight. and have 24v on the red terminal at all times. 24v on the brown terminal with the key on.
4. With the engine running you can use the old school test to see if the alt is working. Hold a screwdriver near the rear bearing and see if the alternator is magnitized
5. Check your belts

beyond these simple tests, you will need to dig deeper into the system

 

[Barrman]

Aside from your charging problems. How long do you crank the engine to get it to start up each time? The thread written by me and linked to a post up happened because my ALT 2 was bad. I drove the truck while figuring out the problem for weeks and only charged the rear battery at most once a week. I never had slow starter turning and probably could have gone 2 weeks between charging the rear battery.

If you are pulling the rear battery down every few days. You either have fuel problems that require you to crank for minutes to start the truck, lots of loose or corroded connections under the hood, a bad battery or some bad wires in your primary battery cables. Something else is also pulling your battery down if just a few starts kills your battery is what I am trying to write.

I will third or fourth the suggestions above that you need to purchase a digital volt meter and get some readings at both batteries while the truck is running.