lights/alternator problem?

[89k5350]

so i get out of work and start my truck, turned head lights on and walk to back of truck to hear my lovely new exhaust and noticed that only my license plate lights are barely barely lit up, no tail lights at all. also when i pull headlight knob the idle was dropping right down. i step on the brake and one brake light comes on farely bright, i noticed voltage was really low compared to usual un less i gave it a little rev. a so i was thinking alternator. the whole rear half of the truck has been re wired by a shop less than a year ago. battery is in good shape maybe around a year old from interstate. anyway when i leave work the dash lights go completely out too. but all the lights in the front of truck work fine. so now no dash lights no tail lights no license plate lights just down to one brake light. by the time i got home it was charged back up to 13 volts(15 min drive). so is a alternator going to do wackey things to lights like that or did i just get lucky and some switch is also going?

 

[kgblazerfive]

loose ground.

 

[chulisohombre]

Sounds like a bad ground to me too. Check that one is still attached from the back of engine block to the firewall. Also at the rear of the body to the frame. On mine the rear one also has the gas guage ground at the same place. Right behind the fuel tank. The front lights are close enough to the batt that it usually doesn't have ground problems. Also check fuses now that the dash and rear lights are out. On mine I believe it's the same fuse.

 

[89k5350]

so I have working brake lights and turn signals now, but dash lights and running tail lights are out. I checked the fuse, it was blown so I put two more fuses in and it blew them almost immediately. so that must mean theres a short some where but its gotta be in the dash because the wirng in the back is fine for sure.

 

[diesel4me]

If you have a trailer hitch and a plug for trailer lights--I would start looking there first!..also look at the connector in the harness under the bed along the frame,see if its half umplugged or corroded..salt gets thrown there by the tires and will corrode things quickly..

 

[blazer74]

New exhaust, burnt harness under truck?

 

[89k5350]

so im workin on truck tracing wires and my dad aks me whats wrong, me: tail lights. then my dads like oh just take your cigerette lighter out of the socket and put another fuse in for the tail lights. so i do and all lights come on and work fine. i took the cigerette lighter out of the plug! and it fixed all my lights

 

[chulisohombre]

Wow. Never heard of that. Glad it's workin.