I have an issue with the electrical system. the voltage fluctuates between what the in-dash gauge calles 12 and 14 volts. when it drops to 12, there is a noticable difference in the brightness of headlamps, heater fan speed, etc. the dash lights, overdrive and other electronic functions have also been rapidly flashing on and off, including the tach, speedometer (all of gauge cluster). It will come back up after anywhere betweek 1 and 45 seconds.

As of right now, I think there may be either a voltage regulator problem or alternator problem. I am also starting to suspect that one of the two batteries are shot, but I am not sure if that is the problem (im going to check them out this weekend anyway)

Any thoughts, suggestions or help that anyone could offer would be appreciated.

 

If what you are describing is happening after starting the motor when cold and cycles several times and goes to 14V and stays there, it is the intake air heater cycling for cold starting and initial warm up. This is an automatic function and is normal.
If you suspect that a battery is weak, by all means get it tested and if poor, replace both batteries. Always replace dual batteries as a set. Best to go with 1000 cca rating or above.

 

I'll 2nd the grid heater diagnosis.

 

The grid heater may be part of what I am experiencing, but the gauge cluster having a mind of its own is a different story..... it will tell me its running 3000 rpm while its idling..... that is my main problem at this point.... possible control unit connections or maybe something else?

 

check your tps and wires for the tps
mine did this once and it was a messed up wire to the tps

 

I was thinking the TPS or the Crank sensor.

If the gauges only do this at low voltage, then I would also check the integrity of the grounds to the frame and the engine. A corroded cable can give you fits. Been there.

 

Check the crank sensor, give it a blast with some electrical contact cleaner, and see how it does. Grounds are a good idea as well. They should be checked and cleaned on fairly reg. basis. Once a year is good practice. Ox gaurd to the connection points will help as well. Good luck, Kevin

 

After you clean the crank sensor, regap it. It should be around .010". Use a brass feeler stock or double up a sheet of paper and use it to set the gap. Make sure the harmonic balancer is clean too. If the mag PU has picked up some metal, you may have to remove the PU to clean it