85 s10 blazer,electrical problem

i have an 85 s10 blazer and when the lights are on or i turn on the blinkers or anything that needs elctricity the power goes down then up then down and so on and i cant drive it any more due to thisthe radio wont even stay on.when ever its at an idle and nothing is on the voltage is normal but once i turn the lights on or something like that it starts messing upeverything goes up and ,all gauges start goin crazy ,the headlights dim down till there almost off, the motor dies down and so on.can anyone help me out,i cant figure this out.

thanx flatire

i have an 85 s10 blazer and when the lights are on or i turn on the blinkers or anything that needs elctricity the power goes down then up then down and so on and i cant drive it any more due to thisthe radio wont even stay on.when ever its at an idle and nothing is on the voltage is normal but once i turn the lights on or something like that it starts messing upeverything goes up and ,all gauges start goin crazy ,the headlights dim down till there almost off, the motor dies down and so on.can anyone help me out,i cant figure this out.

thanx flatire

Step one, you need to have your battery load tested.

Step two, you need to have your alternator output checked.

Do these before anything else.

You want to also check the connections at the battery. A little corrosion on the terminals can cause a drop in power.

You want to also check the connections at the battery. A little corrosion on the terminals can cause a drop in power.

turns out it was the headlight switch shorting or sumthing,replaced and problem solved,thanx guys


flatire