GEN 1 Light and Heater switch

[smoke1]

While driving to work last night, I put my heater switch from low to middle position. GEN 1 light glowed dimly.
Put heater switch to 'HIGH', GEN 1 light came on brighter.
Put heater switch back to middle position, GEN 1 light got dimmer.
Put heater switch back to low, GEN 1 light went out.

At the time I had headlights on, HIGH Beam position, going down highway at 65 MPH, had been running for 10 minutes after starting. So it shouldn't be a charging problem or due to the battery not having 'recovered' from a starting draw down.

Tried putting headlights back on low beam and cycled the heater switch through it's positions with the same reaction.

Cycling headlights from HIGH beam to LOW beam with Heater switch in it's 3 different positions had no effect on the brightness of the GEN 1 light. It was not illuminated when the heater switch was in LOW, dimly illuminated with switch in MIDDLE position, and a little brighter with switch in HIGH.

The GEN 1 light was not fully illuminated like it is when you first turn the Ignition key on.

When I got to work, and before I shut down the engine, I turned off the headlights and cycled the heater switch with the same result on the GEN 1 light.

I don't see anything in the trouble shooting parts of the manuals, nor does a search of the CUCV forum come back with a previous posting covering this.

Any ideas, folks?

 

[mangus580]

Gen 1 is failing. The wiring uses something in the heater circuit to 'excite' the alternator. I suspect you will find something by having it tested.

 

[Recovry4x4]

Dang Ron, thought you gave up on that electrical headache years ago.

 

[CUCVFAN]

I seem to remember seeing this on a truck before, but I can't recall if it was my truck or not. I'll have to check this weekend... Don't recall really fixing it...

I'd check the belt tension first. They don't always make an audible squeal when slipping. If current is flowing through that light then the alternator is probably not able to keep up with the demand when the blower motor is on (or that load causes the belt to slip a little). Check the voltage of the front battery and the flappiness (I know it's not a word, but you get the idea) of the alternator belt with the blower motor on high and see what it shows. If the voltage is fine, then something is inducing a current through the light somehow.

 

[steelsoldiers]

My '09 did that once too. It was the weirdest thing. At the time I had a 12v voltmeter installed on Gen 1 and the voltage pulsed with the light. I put new brushes, regulator and diode trio in it and problem was solved.

 

[thedeliverator]

Had the same thing happen to me, and it recurs from time to time. In my case, it's the belt on Gen1 - the old belt wouldn't stay tight enough under a heavy load. Replaced it, tightened things up, worked fine. Then one of the bolts holding the gen in place slipped a bit (I hadn't torqued it down tight enough), and it started to show the same symptoms.

I really only noticed the faint Gen1 glow at night.

 

[portert0224]

GEN 1 Light dimly flickering intermittently

I just experienced this phenomenon the other night coming back from the first day of deer season. I had idled the truck a lot that day and did not notice the low glow/flicker during the day or while driving back at night from hunting. I only noticed it at idle, as I was about to park and shut down the engine--I did not notice it while driving.

My dumb newbie question is which generator is generator 1, passenger or driver side? And which gen charges which battery?

Thanks in advance,
Tracy

 

[SPECIALTYLC]

Alt #1 is drivers side, Battery # 1 is front. If checking belt tension doesnt fix it, then alt will need a rebuild.

 

[CUCV85]

My '09 did that once too. It was the weirdest thing. At the time I had a 12v voltmeter installed on Gen 1 and the voltage pulsed with the light. I put new brushes, regulator and diode trio in it and problem was solved.

While driving to work last night, I put my heater switch from low to middle position. GEN 1 light glowed dimly.
Put heater switch to 'HIGH', GEN 1 light came on brighter.
Put heater switch back to middle position, GEN 1 light got dimmer.
Put heater switch back to low, GEN 1 light went out.

At the time I had headlights on, HIGH Beam position, going down highway at 65 MPH, had been running for 10 minutes after starting. So it shouldn't be a charging problem or due to the battery not having 'recovered' from a starting draw down.

Tried putting headlights back on low beam and cycled the heater switch through it's positions with the same reaction.

Cycling headlights from HIGH beam to LOW beam with Heater switch in it's 3 different positions had no effect on the brightness of the GEN 1 light. It was not illuminated when the heater switch was in LOW, dimly illuminated with switch in MIDDLE position, and a little brighter with switch in HIGH.

The GEN 1 light was not fully illuminated like it is when you first turn the Ignition key on.

When I got to work, and before I shut down the engine, I turned off the headlights and cycled the heater switch with the same result on the GEN 1 light.

I don't see anything in the trouble shooting parts of the manuals, nor does a search of the CUCV forum come back with a previous posting covering this.

Any ideas, folks?

Mine has done this Generator 1 dim light periodically
about 5 times in 3 years - exactly when the heater is on high,
just as you describe.
You remind me to get my Alternators rebuilt -they are original/25 years old/76,000 miles (It's Time!)

 

[ssgtwright-usmc]

When you described the conditions, esp.. with the heater fan, Low to High, I have the same problem but never added 1 plus 1 together.
I had my alt repaired last year and I still have the same problem.
I even changed alts from one side to the other side and still have the problem.
Belts are tight.
Is their like a faulty relay somewhere in the system that can also cause this problem?

 

[68impalass]

Mine did this a few times, I found the heater fuse to be not very tight in the socket. I cleaned the socket with electrical contact cleaner and haven't had a problem since.

 

[CARNAC]

When you described the conditions, esp.. with the heater fan, Low to High, I have the same problem but never added 1 plus 1 together.
I had my alt repaired last year and I still have the same problem.
I even changed alts from one side to the other side and still have the problem.
Belts are tight.
Is their like a faulty relay somewhere in the system that can also cause this problem?

WOW you mean they have heaters in Hawaii??!! Guess that is for when the temperature reaches that crisp 79 degrees for that on time a year. LOL

 

[ssgtwright-usmc]

WOW you mean they have heaters in Hawaii??!! Guess that is for when the temperature reaches that crisp 79 degrees for that on time a year. LOL

Beleive it or not, here on the Big Island of Hawaii, it actually does snow, it snowed last week on top of Mauna Kea.
Who would think that it would snow in Hawaii?

 

[Mudstone]

my gen 1 light is no longer coming on when i turn the key. should i be worried? also voltage guage is showing yellow not green. I'm pretty sure my ground wire is bad. Also my heater is intermittent and finicky i have to stick my fingers behind the switch and wiggle things to get it to blow. any tips suggestions?