Voltage regulator

S

S-mck

New member
Gentlemen,

Working on my 1973 1200 flareside pickup with a 304.
I believe the voltage regulator is the culprit in my electrical issues, I’ve tried researching them and haven’t found plastic ones, just doing a sanity check for everyone to confirm.
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Your truck is probably a 1970, not a 1973. A picture of the truck and the vin data plate would help confirm. Reason I say that is, for one thing a '73 would be a 1210. Second is a '73 would have an alternator with an internal voltage regulator.

*Also I moved this thread to a more appropriate section for good housekeeping and better attention.
 
Hmm. Ok, well it doesn't belong to that truck, or shouldn't belong to it. Perhaps someone has done some type of crazy retrofit for mysterious reasons. Let's see some under hood pics then. Please show us the alternator and show us where that doohicky was mounted. Maybe we can get to the bottom of it.
 
1210,1973,
 

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That's a 10si alternator, so that regulator is not needed. However some of the wiring to it is missing. There's a plug with 2 wires that go's in the side. You can get the plug at the parts store.
Figuring out how to wire it is going to be challenging in that rats nest of wiring under the hood is going to be difficult.
In short the 2 wires in the plug go to the fuse block and light light on the dashboard.
Nice looking truck.
 
Got it, so what is the purpose of the voltage regulator and the harness going to it? The alternator has a two wire plug in the bottom but it only putting out 11.68 volts
 
And thanks, I’m the third owner, I was told the previous owner replaced the transmission with a older international dump truck transmission, just going by word of mouth
 
Rev it up a bit and see if it starts charging. If yes then the side plug is wired wrong, no and the alternator is suspect.

That alternator looks new. so who knows what was in there before.
 
It's not a voltage regulator at all. It's some type of emissions control device. Any reading below 13 volts while the engine is running is a discharge, not a charge. You should actually see up to 14.5 volts while the engine is running depending upon what load the system is under at a given time. Someone has done some very creative wiring with regards to your charging system. I'll be back with some more in depth advice soon.
 
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First off, the red wire coming from the alternator and looping back up to the battery interrupted by that inline fuse on the fender...that needs to be redone. That wire should be a 14 gauge wire that runs down to the large terminal on your starter mounted solenoid. It does not need fuse protection.
 
Next, trace out the purple wire that is spliced to the white wire at your alternator and see where it goes. That wire is suspect. What should be connected there to that white wire is a very small gauge (thin, tiny) brown wire with a white tracer stripe, which I can still see is present or at least partially present in your loom. That teeny wire is a resistance wire for the alternator "excite" circuit.
 
Awesome, it gets me moving in the right direction, and yes it has a lot of strange wiring, initially I removed several switches in the dash for miscellaneous lights and things. Initially I removed about 8 ft of wiring that went no where, I’ll adjust and repost when I’m done. I really appreciate the assistance
 
No problem. That's a very typical previous owner inheritance scenario. Also, when you're redoing that red wire, the routing path should be up from the alternator, then run rearwards along the engine, nestled between the valve cover and the intake manifold runner, then down at the rear of the cylinder head on down to the starter, mimicking the factory routing. Try to keep wires away from your hot exhaust components as much as possible.
 
On the alternator, the second red wire comes from the battery and a large gauge wire goes to the stud in the back of the alternator,
 
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