dome light is on with headlights on, any ideas ?

[R72K5]

in the 81 i went and replaced bulbs and fuses throughout the truck

well the dome lamp always worked with door switches and with headlamp switch but the instrument panel lights didnt, so i replaced the headlamp switch and put in a bulb in the courtesy light for floor board passenger side, so it works too now

but it and the dome lamp now come on with headlights on, but isnt fully bright but is near to fully bright

any ideas what is causing that ??


have instrument panel lights though at least, but driving at night with dome and courtesy lamps on isnt all that spectacular,

thanks for any ideas as to what to check, hmm...

i am out of ideas and there are no cut wires in the truck cept for radio

 

[big83chevy4x4]

have you check all the fuses? gm wireing does wierd things when a fuse blows.

on my 89 s10, the trailer plugin was wired wrong and didn;t know it, when we plugged it in to the trailer, it blew a fuse. then when we turned on the headlights, the dome lights came on. i forget what fuse it was, but we replaced it and they worked like they're suppose to.

 

[justhorsinaround]

I'm thinkin that your head light switch has gotten dirty and is letting electricity cross over to your dome light circuit, maybe?

 

[R72K5]

hmmm... interesting,



would ahve to be courtesy or dome one since the headlights and instrument panel lights do work, so those two latter fuses are good apparently
but i checked all the fuses

so hmm..

however before this new problem and before i replaced the headlamp switch i replaced a burnt fuse i think it was the courtesy one


thanks

 

[surpip]

Have you tried twisting the headlight switch to the left?
i can turn on my dome lights with my headlight switch, not shure what year this started, but if you turn the switch to the right, it turns on the dome lights.

 

[R72K5]

i messed all around with the headlamp switch knob yes, that started in at least 67, if not before i know for a fact

the cause/problem is somewhere else i believe

all works fine with headlights off

and all was fine with non working dash lights before i swapped headlamp switch out and replaced burnt fuse

its something real small and stupid i know, just unsure what,

somehow the dome and courtesy are getting almost full backfeeed(or whatever you want to call it) from something with the headlights on


hmm

i guess i could try a third headlamp switch

i dunno,

-
thanks

 

[83ZZ502_Jimmy]

Do you have a cig. lighter? May want to unhook and see if that helps. Everytime i blew a fuse, it was realted to the lighter..

My .02,
John

 

[Blue85]

You have a blown fuse.

Here's the deal: There are three "dome lights" in a K5. One in the topper, one on the roof and one under the dash. The ones up top are wired to constant hot and get grounded to the chassis through the door switch. The one under the dash is also tied to hot, but through a different fuse. At least one of these fuses also has some other equipment on it. When you blow the fuse, the bulb under the dash is bridging the top bulbs to some other equipment, through which some current flows to ground. Usually the bulb lights up rather dim since it is in series with something else.

I can't remember which fuse it is that does this, but it seems to me you lose either your parking lights or the dash lights when you have this condition.

 

[darkshadow]

interesting.

remebber it is also grounded at you headlight switch, (white wire i think)

if it was bridgeing inside the switch to a week ground then it could come on too.

 

[R72K5]

its a pickup not a k5 it has two lights only

i guess id have to say its the headlamp switch then

im just gonna have to put in a brand new one instead of trying used oens

hum

fuse i put in hasnt blown, its doing fine


thanks

 

[justhorsinaround]

remebber it is also grounded at you headlight switch, (white wire i think)

if it was bridgeing inside the switch to a week ground then it could come on too.

You mean I could maybe be right?

Hold on while I mark my calendar!!!

 

[Blue85]

interesting.

remebber it is also grounded at you headlight switch, (white wire i think)

The fact that they are both connected together (@ door switch and headlight switch) is the reason this is possible. It's taking away one of the 12V supplies that makes it happen, though.

You may remember a science experiment from school where you put two light bulbs in series. The one with the lower wattage rating lights up brighter.