It should be noted that I recently did an engine replacment (94 engine into the 95). I have heard too many times about ghostly electrical problems and bad grounds after DIYing(?!)
Anyway the problem is that the truck is hard to start on cold mornings. The voltage gage stays low but not a lot. Wipers, windows and fan seem to run a little slower. Running higher RPMs results in voltage increase and brightening of the headlights too. The strange part is that quickly applying the brakes while driving will result in the radio shutting off along with a momentary voltage drop. Gentle application of the brakes do not cause this. Most symptoms are continuing except for the first and last ones (start and brakes) The truck runs ok for now but I haven't been able to actually check the voltages due to the weather. (temp of 0F windchill colder and snow) This may have contributed to the problem...
The battery was replaced 6 months-a year ago. A good quality spiral cell with a 5yr warranty. The alternator is quite a bit older but had no problems with it in the 94 truck.
I'm just not sure if a connector was missed during the engine replacement. The 95 ran fine electrically before, but I have only had this one for a few months.
Reading other posts has given me a few good ideas for my troubleshooting path but it's the brake affecting the voltage that has me scratching my head. Not much about it in anything I read. Can anyone point me in the right direction?

 

If you have a poor/loose ground connection the hard brake application could cause enough movement .

To cause a poor connection to get worse.

If your working in the cold and wind I feel sorry for you.

If you get a break in the weather or inside check your battery voltage with a meter with the engine running.

Should be between 13 to 14 VDC with all the main power loads on blower motor head lights wipers and what ever else you would be using.

Could also be the wire from the B terminal to the battery is getting old and tired.

Ground should go the the engine block not the aluminum manifold or head.

another one goes to the inner fender those would be the two main ones from the negative battery terminal.