Electrical problem, only 9 volts

[whistleman]

My dad has a 91 model, the battery would not hold a charge. So he gets a new battery. Battery will not hold a charge. Gets new altenator. Only puts out 9 volts. Gets new battery and new altenator. Still only 9 volts. Sometimes it will put out 13 volts. Mostly it puts out 9 volts on the gauge. Any ideas?

 

[whistleman]

Found problem

Voltage regulator.

 

[Philip]

In the 91's there are two versions. The 91's have a external regulator.



The 91. 5's with intercoolers have the voltage regulator built into the PCM (powertrain control module).



So the question is. Does the truck have a intercooler in it???

 

[R C Cola]

9 Volts

Even if yours is internal you might want to put on the external regulator since it is an easy conversion (see other threads) and simpler. You can go to autozone and hook up for free in truck and read exact volt output, etc.

 

[Ctdchris]

And the externals are only about $15 on the expensive side.



Chris

 

[DieselBuzz]

Check the ground in front of the battery on the rad. support. Mine was loose and it made my voltage gauge drop for any draw. Good luck.

 

[Belchos]

I doubt it is the regulator. Sounds more like a voltage drop from some kind of resistance. Probably ground.