Gen2 light on

[Drock]

Hey guy's I'm half way through a 600 mile trip and the Gen 2 light is dimly lit, and staying on. The belts are all tight and the volt meter is reading normally. (1st) Can I make it the rest of the way home? (2nd) Is there some simple things I can check for till I can make it home to my tools?

 

[TGP (IL)]

Not sure if anyone can predict that you'll make it or not.
But with that said, Gen 1 is supplying the 12Volt power for the truck,
You should be ok.
If Gen 2 gives out the rear Battery could die preventing you from starting.

Now we'll see if I'm correct in my thinking.

Wiggle the two wire plug on Alt 2 and see if it help

Tom

 

[Tow4]

Generator 2 only supplies the rear battery. The rear battery is only used for starting and the glow plugs. Drive it home.

 

[cucvrus]

I have had this issue a few times while wheeling. I have had great success by tapping on the alternator gently at the rear area where the brushes and springs are. It has helped seat the brushes and clean the mud out just enough to get the alternators charging again. But I had a dim Gen 2 light in Terminus for 2 years now. Never effected a thing and the needle on the volt meter is at the correct charge rate. good Luck.

 

[MWMULES]

So did you make it home ok??

 

[cucvrus]

That's a good question. Drock??? I made it home fine but mine was on a trailer. Thanks for asking

 

[Drock]

Yes, thank you guy's. I made it back late last night and had some errands to run today. The light is still on, but everything seems to be working fine. It did go off for a short period today but is back on again. I unplugged the wire on the top of alt #2 and checked it. It was clean and greased, I think tomorrow I might spray some parts cleaner inside the alternator to see if that has any affect, As well as undo & clean the connections on the back. Also, Is there a fuse I can check?

 

[cucvrus]

No Fuse. I suspect a diode weak or the brushes not making good contact. That is what my shop always tells me when I say something about the dim light. I am going to let an electrician friend eliminate the combined circuit for Gen 1 and the heater motor on one CUCV unit. Just because he said he can and I continue to see a dim light at times. I have tried everything. Oh well glad your home.

 

[joshuak]

There is 10 amp fuse for the gen 2 light in the fuse block and also a relay for gen 2 next to the starter relay.

View attachment CUCV Fuse Panel.pdf

 

[cucvrus]

There is 10 amp fuse for the gen 2 light in the fuse block and also a relay for gen 2 next to the starter relay.

View attachment 690408

My answer as NO FUSE was a fuse will not make the light dim. That is an internal alternator or connection issue. I suspect a weak alternator. That's just me. Always has been the fix. Have a great day. Good thing to do is get both alternators refreshed if you are going on long trips. I have dim on both my alternators at this time. I know why.My alternator fans are like chrome on the ends and the cooling fan looks like polished aluminum. Still charging fine but dim lights on both. Tap Tap lights out.

 

[Drock]

I found alternators and rebuild kits on Ebay. But they don't tell you which one they are? Doesn't one of the alternators have a special ground?

 

[cucvrus]

When I have mine rebuilt they are interchangeable. Both build the same. Hope that helps.

 

[Tow4]

I found alternators and rebuild kits on Ebay. But they don't tell you which one they are? Doesn't one of the alternators have a special ground?

Before you do anything make sure the alternators on the truck are isolated ground. The passenger side has to be. Originally, both were isolated ground. If you have the original alternators on the truck, don't exchange them as a core if you buy a new one. They are not available any more and you will probably end up rebuilding one or both.

I also sell the alternator rebuild kits. There are links in my signature to my alternator rebuild thread and classified ad for the rebuild kit. I suggest you look at the rebuild thread to familiarize yourself with the alternator if you are not sure what you need.

 

[LastFbody]

Had this issue on my truck when I bought it. I didnt think it affected anything, and my original voltmeter was reading in the green, so I left it alone and paid it little mind. That is, until it didnt start lol. Its probably a diode like cucvrus is saying, but its a good opportunity to do a full rebuild. Had a local shop do mine for $40 and had no more gen 2 light related troubles.

 

[Drock]

I need a little electrical help with this one, I checked the voltage of the little plug on top of the passenger side alt and it reads 12V... I think? And when I checked the drivers side alt plug it was zero? Gen1 is drivers side & Gen2 passenger correct?

 

[cucvrus]

Gen 2

Correct. 1 on left and 2 on right. Just like they are in the cluster. Good luck. I think you must ground the wire to Gen 2 to check that voltage because of the grounding. I am weak in this area. I still get them working by trial and error. Most times fresh professionally re-built alternators fix all my charging ills.

 

[Drock]

Well finally I got around to re-building the alternator today. But the Gen2 light is still on? And also now I've noticed one of my (Optima batteries) is leaking acid. Could this be my problem? A bad battery?

 

[cucvrus]

Battery leaking will NOT make the generator light illuminate. Did you check the output with a voltmeter? That should be putting out about 28 volts.

 

[Drock]

Battery leaking will NOT make the generator light illuminate. Did you check the output with a voltmeter? That should be putting out about 28 volts.

Update,.. The problem persists. Rebuilt the passenger side alternator & Just replaced both Optima yellow top batteries, No joy, the light is still staying on dimly lit. I checked the voltage of GEN2 and I get (27.1), and on GEN1 I get (12.1). I read on another thread that there's a "diode" (whatever that is?) behind the gauges. Could this be the problem? For that matter I'm I having a problem? could it be just the light itself?

 

[cucvrus]

Quick question. Did you rebuild it by replacing the internal parts? I am asking because I been to a shop where they rebuild these electrical parts. They have a lot of testing equipment and are able to diagnose things better then the average guy. I heard of diodes going bad to the connection at the heater fan motor causing these dim light conditions. As far as I know there is nothing on the back of any cluster I ever had out to effect the light. Just a printed circuit board on a flimsy plastic sheet with copper strips imbedded in it. Good Luck. I say go to a good job if you didn't already and check out the fan wire /fan switch connections. Have a great day.