1996 Chevy S-10 No Electric

BILLROTH59

MEMBER
1996 CHEVROLET S-10
4 CYL
2WD
MANUAL
136,000 MILES

I bought this truck used 2 months ago. Last week I drove to the Florida Keys and had to replace the battery. The alternator tested good. It did push start fine before I replaced the battery. Drove all day yesterday with no problems. Parked at a friends and came out later and there is no electric in the truck. No dome light, hood light, flashers, gauges, nothing. The battery connections are tight. The battery tests at 12.88 volts. All the fuses in the dash by the driver's door are good. The truck will not push start either. What can I start to look for? I'm an electrician but I only know AC voltage. I have a basic understanding of DC but I am pretty ignorant with vehicles. One thing weird though, to start the truck, you have to turn on the running light switch. You can turn it off once the truck started. I was told it was an anti-theft trick.

Thank you for your assistance.

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

Get an analog voltmeter remove the negative battery cable, attach the Black lead to the battery post, Red lead to cable end, then pull fuses one at a time, make sure there are no accessories or lights in the on position, Key off! Close the door have someone in the car, pull fuses one at a time after each fuse check meter, when you pull the fuse for the bad curcuit, the meter will drop to 1 volt or so. Check all fuses, even under the hood. If meter does not drop, remove the battery connection from the alternator, if it drops now, the diodes are bad in the alternator. Put the fuse back in were it goes as you go so you don't forget which fuse goes were! Wait several minutes after hooking up the meter before pulling fuses, test with a good battery!
https://www.2carpros.com/first_things/why_is_my_car_battery_dead_over_night.htm