Gen 2 lamp stays on for quite awhile after started

[twomorestrokes]

Did a search and could not find anything on this particular problem. Charging system was working great until one morning I noticed the Gen 2 lamp was burned out. Replaced the bulb and socket and lamp stayed on while running and Gen 2 was not charging. Lamp would go off after about a mile of driving and alternator would start charging. Now that it's colder the lamp stays lit longer. This morning it stayed on almost 10 miles then went off and alternator started charging. Once charging, everything works fine until I shut it off and restart. Even if it's just shut off momentarily Then I need to drive awhile again before Gen 2 circuit starts charging again. Sound familiar to anyone?

Belts are newer and I have tightened them with no change. Fairly new military batteries. Truck cranks fine even in zero degree mornings.

 

[patracy]

Did you replace the bulb with the same wattage?

What happens when you rev the engine hard at idle?

 

[Warthog]

When did you last rebuild the GEN2 alternator?

 

[twomorestrokes]

Did you replace the bulb with the same wattage?

What happens when you rev the engine hard at idle?

The bulb is a 194 and the rest of the dash bulbs are 168s. I believe that I read that this is correct. Revving the engine does not do the trick like it used to. Even driving the truck at 65 mph does not put the light out until it's ready to start charging. The truck has 34k on the odometer and has reman stickers on the alternators but I can't say from when. I bought the truck this last summer with 32k on the odometer. At that point the truck had two brand new batteries and belts but only two bulbs worked in the cluster. The Gen 1 bulb and one speedo bulb. I rebuilt the cluster with new bulbs and a few sockets and everything was fine, until I noticed the Gen 2 bulb was not lighting so I put another bulb in with a new socket.

 

[Warthog]

Sounds like you need to rebuilt the alternator. At least take it apart and test the components.

 

[twomorestrokes]

I will have to do that when it warms up a little outside. The 1 downside to my truck being so tall is that I can no longer fit it in the heated garage. I don't know that much about this 24 volt system but apparently if the front battery is charging it eventually makes it back to the back battery? I left my lights on yesterday by accident and killed both batteries dead. I hooked the charger to the front battery for a few hours and both batteries came back nicely. Started right up this morning at 5 below 0.

 

[twomorestrokes]

Just thought I'd give an update on this in case it helps somebody. I bought a 168 peanut bulb at the store and swapped out the 194. Gen 2 system starts charging as soon as rpm's come up like it used to.

Thanks for putting that into my head patracy. Information obtained on this forum states Gen 2 bulb should be a 194. Even though the burned out bulb was a 194 and the first replacement was a 194, something was goofy in the wattage draw and wasn't exciting the second alternator like it should have. Works fine with a 168 bulb in the system but the red light is definitely brighter than ever. (same brightness as the Gen 1 lamp now)

 

[doghead]

Good info!

Updates really help to.

Thanks