I have a question regarding an electrical issues with possibly a short somewhere... I just got my battery tested and a new alternator, and when i turn on my lights, or even my heater and everything in between my gauge voltmeter drops traumatically and almost kills my truck... when i accelerate my meter still doesnt move and my truck kinda tries to die...
Any help would be greatly appreciated thanks...

 

Did the problems show up after or before "I just got my battery tested and a new alternator"?

 

before, i have been trying to figure this out for a few months now

 

sounds like some bad/corroded internal wires. rewire your ground off of the alt and check the + white wire from the alt. as well as the smaller wires that go into the back of the alt in the plug. or just do the gm 3 wire alt and life will be just fine.

 

I would check all grounds. Link>>> https://www.yotatech.com/forums/f116...-guide-194413/

 

The alternator grounds through the bracket to the block.

It might be time to upgrade the battery terminals and cables along with the wire off the B terminal of the alternator. All these things can cause issues in starting or charging.

i have also seen the plug on the alternator get corroded and being where it is a real pain to get clean.

every Toyota that comes through my place I do this just because it cures so many starting and charging issues.

 

last time the alternator went out on my dads 87 we had to get 4 alternators before we got a good one they each only lasted about a week and half there wernt any wirin probs on his just bad new parts

 

thank you all, very appreciated.. ill let you know what i come up with

 

One other thing I would suggest you check is the (+) wire that goes from your positive terminal into your fusebox. These have been known to corrode and/or absorb battery acid and affect everything electrical in your truck.

I had a similar problem to yours, the engine ran fine most of the time, but if I was driving at night and it was raining the windshield wipers (on top of the headlights) would draw enough current to stall the engine. I went through all the grounds, replaced the battery cables to no avail. Finally I traced the wire from the battery to the under-hood fusebox, and found the cable crimp had nearly corroded away.

 

This suggests that alternator output (assuming you have good alternator) is not getting back to the battery and power distribution point (under hood fuse block)

Agree with checking wiring thoroughly for corrosion. Do not trust connections that look good outside. i.e., battery post and connector may look clean but contact surface/interface could be corroded

Many ground points have painted sheet metal, continuity to ground and relies on contact from threads to coated screws, to ring terminal. I would not trust that because threads and screws could get dirty/corroded. I sand down to bare metal and clean ring terminal (below). This way, ring terminal makes direct contact with sheet metal ground. Then I use conductive grease on all contact surfaces, to prevent corrosion.

 

i'm having similar issues. new battery, new alternator, battery not being charged by alternator.... ugh. good post here

 

I always have a double check if I have to buy an alternator. You could always rebuild the alternator yourself. Its cheaper and not really that hard. The last time I did mine NAPA had all the parts in stock. Just a thought.