So when I measure AC I just put a multimeter on AC volts and touch the terminals right? I know it shouldn’t be a lot but it should be a small amount right?

 

Had the same problem with my external voltage regulator...several times. Each time it was the power wire going to the regulator. I have mine rigged with a relay that is connected to a switched circuit (the cigar lighter I believe) in the cab fuse panel. Anyway, that wire that powers your regulator from the battery (thru the relay) then back to the regulator MUST be at least 12 gauge or thicker. If not, you'll get fluctuation sooner or later, likely sooner if not right away. You may even get fluctuation with a 12 gauge eventually but replacing it solved the problem. Considering going to 10 gauge next time.

 

IIRC my wire is 16 gauge so I’m sure that would be an issue. From what I read that wire is just supposed to trigger the regulator to turn on, so that’s why I went with 16g

 

#14—15a-25a

#12—20A-30A

#10--30A-40A

bronze, That external regulator takes 20Amps to turn on ? Or it takes 20Amps to turn the Alternator on ? Or is something else in play ? And about ealyer, I think my Daks battewry and/or alternator is not keeping up with the demand. Because,(I keep remebering stuff) the battery goes dead about every 30 days. I have to charge it with my trinckle charger from Monky Wards.

 

I thought my old Craftsman charger was an antique. You get me beat with that Monkey Wards.

I don't know how you have yours wired up. Somewhere's along the way you have battery power going to your regulator. Perhaps you run a wire from your battery to a relay first and when the relay switches it sends the power thru another wire that goes to your regulator (one of the two wires coming out of the triangular regulator plug). All the wiring from your battery to the relay then relay to the reg need to be 12 gauge or fatter. If they're thinner you will get fluctuation. There are other ways to rig this up but I found this was about the only way for me because I couldn't find a convenient power wire to tap into that was from a "switched" circuit.

Tell me, are you going straight from your battery to the regulator?

 

Its 16awg from battery-fuse-relay (ignition triggered)-regulator

 

Go to 12 gauge. 16 gauge is OK from fuse to relay. A relay is basically only a switch and doesn't need much to trigger it. And 14 gauge is OK from regulator to alternator (the two field wires) . But the actual power coming from your battery and going to the regulator (whether directly or thru a relay) has to be 12 gauge or fatter. Make it all 12 gauge if you want...wont hurt anything.

Send pics if you have any. I'd like to see exactly how you have it wired. Even a crude drawing will work.

 

I guess to save me the pain of ripping apart my harness I can use the existing 16 gauge regulator trigger to be the trigger wire of a relay which is then fed by a 12 gauge wire directly from the battery into the regulator. What exactly is the reason it needs to be such a thick gauge? Everything I’ve seen is it’s just a trigger wire and it tells the regulator how many volts the battery has

 

Oops see next reply

 

Yours is wired differently than mine. I go straight from the "switched" fuse in the cab to a grounded relay mounted in the engine compartment using 18ga wire. I also have a 12 gauge wire going from the battery to the relay. Then I have a 12 gauge wire coming out of the relay running to the regulator (I splice it into one of the field wires coming from the regulator plug, the wire that connects to the top/bottom pin depending if your reg is rightside up or upside down). Then I have the two wires coming out of the reg plug going to the two terminals on the alternator (14ga). I also ground the regulator by going from a mounting screw toa ground point of the alternator (10ga but can be thinner probably).

Here is the relay.and 4-pin harness I use (scroll thru the pictures). Note the four wires. The white one goes to your switched fuse in the cab. The black one is your ground (run a screw through the sheet metal next to the relay mount). The blue wire goes to my battery (12ga). The red one goes to my regulator (12ga).

Here is the regulator plug I use. The two wires go to your alternator terminals. Additionally, I splice the 12ga power wire with the blue wire on the plug. Yes, that means you will have three wires to connect to one another. The pigtail wire coming out of the plug, the wire you send to the alternator, and the power wire coming from your relay. This needs to be a good connection. I simply wrap the two smaller gauge wires around the 12ga power wire kinda stacking it as I work my way up and then secure with a wire nut.

Three way like this:

I can't figure out how you have yours wired based on what you have told me.