12si woes and frustrations.

Installed the Delco 12 Si and wired it up as recomended by thousands of threads on the internet, but I have a problem.

At initial start up the ALT will not charge and the "idiot light" stays off.
When I rev the engine it will begin to charge but the "idiot light" turns on.
I have a diode between the terminal and the "idiot light" I'm not sure if it needs to be there or not.
I'm at a loss.

Any insights would be greatly appreciated.

Donald

 

I recently did a 12si install,

How is it wired? There is a few ways of doing it.

Are you just going by your light or are you measuring the voltage with a meter?

This would also get more responses in tech

 

ignore the stuff on the dash and measure voltage output with a mulitmeter directly.

 

http://delcoremy.com/Documents/Alte...SI-15SI-installation-instructions_105116.aspx

Did you wire it like this set of instructions?

 

If you run a wire from the alternator hot to the #2 pole on the side, it makes it a single wire alternator.

 

I fixed it. Had a bad connection somewhere in the line. Holds about 14 volts when running.

 

That should work for you.