Gen 1 Light Romantic Glow

[dependable]

A civilian K-5 will usually have a 60A alt. Output of both alternators needs to be the same if your truck is 24V.

 

[Mainsail]

Here's a shot of the alternator, looks to be an isolated ground given the fiber washer under the ground bolt?



I tightened the belt and took some readings from the front battery.

First pic is post to post on the front battery, at (warmed up) idle, the second is with the prybar jammed between the gas pedal and the front seat, RPM unknown but guessing about 70% or so.

 

[Tow4]

Yes, that's an isolated ground alternator. The voltage should not exceed the regulator set point which is 14.8. I would give it about 0.20 volt variation, but 15.25 is a little high. It should also reach the set point voltage at idle if the battery is good. Check connections on the regulator plug and voltages at the alternator terminals. If the sense connection is dirty (regulator terminal #2), the voltage will be high.

 

[Mainsail]

Heard a loud THUMP on the front stoop, sounds like an alternator.

So here's the new one. What's supposed to be happening in (unthreaded) hole R there? I have a wire going there on the old alternator.

 

[dependable]

That is for the wire for the tach sensor in the STE/ICE test machine.

 

[Mainsail]

With that out of the way I got to work on it this afternoon.

Used practically every tool I own on Step 1, disconnect the batteries. I shouldn't get frustrated; it's always that way. I really need to look into replacing the cables.

Went pretty smoothly after that. I opted to put my old pulley on the new alternator, as the one that came with it was smaller in diameter. Hit a snag in that the old pulley wanted to be right against the fan, not slightly off it. I dug in my vast collection of NOS washers and found one with a center hole big enough and used that.

Once installed I warmed up the truck and measured the voltage at the front battery at 14.36v

The voltmeter on the dash didn't rise with engine RPM like the old one so I took it on a quick 10 mile drive around town.

Satisfied it's fixed. Back to being my daily driver tomorrow when I go to work.

Now I need to see about rebuilding the old one and stuffing it up in the rafters somewhere.

 

[HeisenBob]

Thanks to this thread, I was able to diagnose and rebuild my driver’s side alt which fixed my issue as well. Thanks fellas.

now on to the next issue....

 

[Keith_J]

It took me 30 minutes to overhaul each alternator, including bearings and bandaging my finger. Just be careful driving bearings out.
I've sourced domestic bearings too. The only issue is the aftermarket regulator. Had one fail, causing over volt, blown diode and thrown belt..probably caused the battery to fail later too.

 

[HeisenBob]

Quick Update: so the romantic glow returns when I turn on the heater blower. It immediately goes away when I turn off the blower. What gives?

 

[TheMod]

Quick Update: so the romantic glow returns when I turn on the heater blower. It immediately goes away when I turn off the blower. What gives?

Mine has always romantically glowed with blower and high beams on. If it's pitch black I can see the faintest of glow with the blower on high only but it has always been visible with high blower and high lights. I always assumed this was normal behavior?? as voltages have always looked good.

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[HeisenBob]

Mine has always romantically glowed with blower and high beams on. If it's pitch black I can see the faintest of glow with the blower on high only but it has always been visible with high blower and high lights. I always assumed this was normal behavior?? as voltages have always looked good.

Sent from my moto g(7) power using Tapatalk

Interesting....maybe it’s normal then. However, I just got back from a quick trip into town. I ran the blower/heater on high, lights on, and had the windshield wipers on full blast. The alt gauge stayed in the yellow on my way into town and the wait light came on and stayed off for the remainder of the trip to the store (about 5-10 min).

I was in the store for 15 min and started the truck up to head home. Alt gauge went to green and stayed there all the way home with the blower/heater on high, lights on, and wipers on.

any thoughts?

 

[TheMod]

Interesting....maybe it’s normal then. However, I just got back from a quick trip into town. I ran the blower/heater on high, lights on, and had the windshield wipers on full blast. The alt gauge stayed in the yellow on my way into town and the wait light came on and stayed off for the remainder of the trip to the store (about 5-10 min).

I was in the store for 15 min and started the truck up to head home. Alt gauge went to green and stayed there all the way home with the blower/heater on high, lights on, and wipers on.

any thoughts?

Not sure on that. My alt gauge always goes to the green and stays there after start. Doesn't move even when gen light glows.

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[Keith_J]

A civilian K-5 will usually have a 60A alt. Output of both alternators needs to be the same if your truck is 24V.

Each alternator is 12 volt, charged one battery. There is no need to have identical alternators.

The romantic glow is probably from a bum ground.