, charging problems

Replace battery first,then the charging system can be properly tested.

does it do the same thing with only the parking lights on....?

Old carpenter when I turn on the parking lights the meter goes down below half way but then when I turn on the lights fully it goes basically almost to the negative side

Old carpenter as a as we speak I'm just got done pulling out the starter and making sure all the terminals are cleaned off that there was no wires connecting at the bottom but everything looks pretty good so I'm about to put the starter back on and see if that helps anything by replacing the positive cable

why are you pulling the starter when you have a charging issue?

Cjsras I was going thru looking for any grounded out wire or lose connection

Carl, I asked about the parking lights to try and isolate where the problem may be coming from. You say the truck runs fine and the voltage guage reads normal without the lights on and the voltage drop is not as bad with only the parking lights on. so, if it was me i would start troubleshooting the headlight switch and circut...you may have a hot short in the light switch and/or lights circut...especially because there is a difference between the voltage drop when just the parking lights are on and it gets worse when the head lights are turned on...