Team Chevelle banner
1 - 4 of 4 Posts

· Registered
246 Posts
Discussion Starter · #1 ·
Ok I am sure you guys can provide some help with this. I am having charging problems on 75 [email protected] 3/4 Ton. Problem is, it isn't charging. From one of the heavy gauge wire from the alt I am getting ~16V, the other OV. ~16V is a little high so I though it might be a problem with the Regulator so I put a new electonice one on. Now the wire reads ~26V, so I am assuing the new regulator is toast.

The truck has dual batteries, and is wired to charge a trailer battery as well, so that complicates it even further. At the isolator, the alt wire reads ~16V (middle terminal). The wire to the trailer reads ~16V. The last post to the batteries only reads battery voltage ~12V.

I tired going staright from the alt to the battery, that brings all the voltage down to battery voltage, with no apparent charging. Also the ampmeter in the truck won't read anything.

So any guesses? Alt toast? There's two 12gauge wires going to the alt, hooked up to 2 different points, should they both read the same?

Another wierd thing I noticed. The isolator seems to only be there to isolate the trailer battery from the two truck batteries. The extra truck battery has a normal Ford starter solenoid on it, that isolates the main battery cables from each other, energize it and it puts the batteries in parallel. However there is another smaller solenoid that connects a 12gauge wire between the two batteries. The solenoid is energized when the ignition is on, effectivley always keeping the batteries in parallel when ever the ignition is on, in this case draining both batteries while tyhe ignition is on. This just doesn't seem right to me, but has worked for the last 20 years. For now I am gonna unhook the 12g connecting wire, so I can just boost the extra battery.

If worse comes to worse I'll just re wire the whole damn thing the right way with a GM altenator. :D

Thanks for any help
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.