Voltage Issue

[pacman1967]

I have an 85 c10. It has the TBI engine switched out for a carbed SB. I have moved the battery to the bed and the power cable straight to the starter. It has a 3 wire alternator that I had tested at two different places to make sure it is good. The problem I am having is when the truck is running my volt meter is pegged out past 18 volts. I bought a second volt meter to make sure mine wasn't bad, and it also pegs out past 18 volts. What would cause my volts to be so high??? Is it a possible starter issue, a wiring issue? Any help would be great.

[hatzie]

TBI started in 1987. The stock 1985 engine should have a Rochester electronic feedback carburetor... Or do you mean you have an 87 or later engine with the original carb?

On to the real question...
It's likely a wiring issue.
The SI series alternator #2 sense lead should be connected to the battery at the 3/8" starter BAT terminal via a fusible link. It could overcharge if this connection is not made.
Did you hook up the two fusible link wires at the 3/8" BAT terminal on the starter?
Are either of those fusible links damaged?
With the engine off... What does a voltmeter read at the battery and at the J-block stud on the firewall to the engine?

[pacman1967]

With the engine off it shows 12ish volts. I have investigated the wiring and it is all shorts of hacked up. The fusible link wires are no longer on the truck. I am going to have to rewire some of the wiring harness that has been cut into and spliced. I found that a lot of the stuff added in the wiring system before I bought the truck didn't have fuses so I am out a tachometer, a electric fan and possible the coil in my distributor.

[Dead Parrot]

As a test, jumper from the sense wire to the output post on the alternator. If your volts drop to 13~14, your current sense connection is bad. If they stay at 18+, your voltage regulator is likely toast.