Voltage issues (1 Viewer)

[Boogie Chicken]

Freeking electrical.

I am so envious of you guys that get electrical. So I have a sbc swap in a 76 40. I installed a fast fuel injection system (whole nuther discussion) the fuel injection system comes with a read out of the voltage. On start up running 12.5. When the electrical cooling fan kicks on drops to 11.5. I have a yellow top battery about 2 years old and just installed a 140amp alt. no change. My question is could the voltage regulator be affecting this. Could I or should I bypass the vr since the new alternator are internally regulated. The low voltage is causing some issues with the fuel injection system among other things.

 

[Boogie Chicken]

never mind just disconnected it and nothing happened

 

[vtgbeemer]

Have you charged the battery fully overnight and gotten a fully charged voltage reading? It should be about 13.2 if the battery is healthy.

 

[Jerry D.]

How much current (amps) does the cooling fan pull?

Did you upgrade the cable from the 140 amp alternator to the battery? Too small of cable will drop a lot of current through it.

Where does your voltage meter read from, the battery, or elsewhere?

Does the alternator have a larger ground cable?


Jerry D.

 

[RAYJON]

what 140amp alt did you install, the cs144's are 100amps at idle and will run 14.8 volts, you have to wire them correctly with a resistor or light in the sensing wire but other than that they are great, a 140amp SI style alternator will only put out about 30-50amps at idle and wont support fuel injection and electric fans... good luck