Alternator or Voltage reg? 73.5T

[mike walker]

My red light came on suddenly yesterday, no flickering just red. Is that a voltage regulator problem, no flickering? I haven't changed a alternator in a while, are the 73.5 VR intergal to the Alt or is it on the side? Thanks in advance.

[Kjell]

This could be a broken fan belt, check this first, immediately as your engine will
overheat without the belt. Your alternator has a separate regulator mounted
on the drivers side of the engine compartment. Typically a bad regulator will
cause an overvoltage condition. So, if problem is not fanbelt alternator is likely.
If you install a new alternator, you can upgrade to a newer internally regulated
unit (with some modifications). If you stick with old style, I recommend you
install a modern solid state voltage regulator.

[mike walker]

What modifications?
Thanks

[Kjell]

Hi Mike, as I recall the newer alternators are slightly longer so the fan housing
needs to be machined (where the generator seats). Also you will need to
do something with the unused wires that went to the regulator. Another thing, the alternator warning light will not work without some wiring mods. You can compare the wiring diagrams for your year and a later year to understand the
differences.

[Gumby]

First you have to trouble shoot to find out if it is the indeed the voltage reg or the alt, To locate the trouble, first you use your volt/ohm meter and test across the battery with the car running ( 13.8 + -)good , if voltage is low ,you can test if the field of the alt is working by shorting out the two leads on the voltage reg to excite the field of the alt , BE CAREFULL! only do this for 1-2 seconds while checking voltage at the battery! ..if it shows 13+++ the alt is good and you need a regulator , if no change then pull the alt and bring it to a shop and have them test it and repair ( mutch cheeper than replacing ) On my 73.5 the voltage regulator went. Good luck .Ron

[mike walker]

Thanks, I may just buy a VR and try it. If thats it, fine, if not I'll remove the alt and send it off. In any case I would probably would replace the VR anyway. Thanks
Mike