i recently bought a 2000 ram 4x4 sport. 5.9 auto if it matters.

whan i first bought it the L turn signal had a bad ground. the dash light lit for the l turn signal lit when you turned on the lights. the lights both worked with the turn signal and running lights but they were just dim. i replaced the bulbs first with no luck. i cleaned the grounds under hood and nothing. test lighted the ground wires for ground connection 1" away from the stud with a test light and it lit, so i hacked it and hot wired the ground lead to the body and they work perfectly now.

my problem now is the fog lights won't work. with a test light they have constant power to them even with the key being off. i can hot wire the ground with the key in my hand and the lights off and they both light with proper intensity. there is NO parasitic draw. i can leave the truck sit for a week and never get a dead battery.i put a HF VOM meter on the battery after sitting for a week and it held 13v.

i checked every fuse under dash and under hood and they are all good if it matters.i previously cleaned the grounds on the left side under the battery.

i am a auto body tech and wiring isn't my strong suit. any ideas on where to look first?
my first guess would be a bad light switch but that's just throwing parts at the problem.and hope it works. and i don't want to spend more $$ on this rust bucket beater if i don't have to.
maybe hook the test light and check the harness for ground? ( didn't think of this when i was looking earlier)
maybe unplug the switch and see if the constant power goes away?
are the 2 lighting problems possibly related?

thanks in advance for the help.

 

Don't we all just love wiring issues.

I suspect that your fog lamp switch provides the ground path for the circuit, but, not 100% on that. Grab yourself a service manual, wiring diagrams are in 8W.

 

Right, if the lights will work but the switch doesn't ground them to turn on, then the switch may be bad or the connection to it. Pull the dash bezel and you can remove the headlight switch to the left of the steering wheel. There isn't a lot of slack but you can see the connections. Test there.

 

THANK YOU everyone for the replies.
first thing i should do is make sure the switch is properly connected. if it is sounds like i have to check my service manual wiring diagrams. find the ground wire for the H/L switch, hook up my test light to a power lead then check if my ground wire is grounded.
if i have ground i will need a switch. if no ground i need to get a ground.