so I have a 1990 extra cab v6 5 speed 2wd. It’s bagged. I know I have a short in the lighting because when I have parking lights turned off the blinkers work fine but when I turn the right blinker on all the parking lights flash with it but if I have my parking lights on the right turn signal stays on. All exterior turn signal lights stay on and dash right turn indicator stays on. I’m digging into that shirt to find the issue. But the bigger issue I am having is the truck won’t start unless it’s jumped. Alternator is charging good. I could possibly have a weak battery but it’s reading 12.4 volts and won’t crank. But as soon as I hook up another car to it it will fire up the first crank. No hesitation. What r ur guys thoughts. It’s just hard to check for shorts when I can’t get a reliable start with out jumping it. Any input will help. Thanks in advance

I’ve had the truck for about 4 years. Been parked for over a year. Both issues started when I just pulled it out the other day. I charged the battery up and over night it drained its self while I’m hooked from the truck. I’m gonna re do the whole battery system and run two batteries. Gonna go threw and re do a bunch of the wiring and change out a lot of the grounds and see where that gets me. Thank u for the fast response. I just have so much power going out between the sound system and the compressors for the bags. That I need to do a lot of upgrading.

One question i on I do have is can I run a bigger wire from alternator straight to the battery or does it have to go threw the fuse box.

Like mentioned above, possible bad ground at the lights sockets. Buy check everything there.

Re: no crank​​​​...
Start by cleaning up all your power wiring. ALL connections to the battery, not just the cliched "check grounds".
​