headlight problem.

[redneckaggie]

I did the headlight mod about a year ago and now i lost my brights. I have checked everything and it is wired right. I tested all the connections and seperately they all have the appropriate power but when you hook the wires into the bulbs every wire loses power except the switch on. Would this be a bad relay or bulb.

 

[88bigblue]

Headlight mod? I have a similar problem. Only my brights work, I click it into low beams and the headlights turn off. Sorry I cant help, but maybe its the same problem.

 

[Goofyexponent]

I would say relay?

 

[sassyrel]

relay--assssss, not all relays are of equal quality--contacts are made of diff things--and some aint so good--hence burn the contacts, and dont last as long---seen it once toooo often--check the incoming trip wire for the relay--wire hot--relay bad--unless the ground for the relay is defective--

 

[redneckaggie]

Ground is good everything has power when the wires are disconnected from both bulbs. connect either plug and everything on the relay goes dead, disconect again and its all live again it is puzzling the hell out of me.

 

[NoDaK]

+1 on the relay being bad...

 

[cm1hedge]

Check circuit breaker, if it has one. I had to chase a turn signal gremlin on a freightliner. It ended up being a bad circuit breaker. It would allow power with no load, but would not work under load. Mimicked a bad relay.

 

[Devilish]

Relay is my first thought

 

[redneckaggie]

ok well the local oreily doesnt have a relay in stock so i guess i will just have to wait till it gets in.

 

[sassyrel]

ok well the local oreily doesnt have a relay in stock so i guess i will just have to wait till it gets in.

if they aint got it in stock--try and get a diff relay plug--and change it to a common one--that way no matter where you are,if it dies,they probably have it on hand--

 

[Greenie]

Where is this headlight relay located?

 

[Agnem]

A volt meter or a test light would make troubleshooting this very easy. Why are you guessing?

 

[nappy nate]

Where is this headlight relay located?

These didn't come with one from the factory and the headlight mod adds a couple of them.
nate

 

[Greenie]

I lost the low beams - new bulbs and a relatively new dimmer switch turn signal assembly. If there's no relay then it must be the dimmer switch.

 

[MIDNIGHT RIDER]

redneck, with the headlights UN-PLUGGED, do the appropriate contacts in the head-light sockets light the test-light ??

A standard 5-prong "ice-cube" relay is nothing more than a spring-loaded magnetic switch.

The "trigger" wire and it's GROUND are completely electrically isolated from the HOT and LOAD terminals, regardless of whether the relay is ON or OFF.

Switching the trigger wire ON sends it's current through an electro-magnet, thus pulling the internal guts of the relay together and closing the internal contacts between the HOT and LOAD terminals.

Switching the trigger wire OFF turns OFF the electro-magnet and the internal spring returns the internal switch to the OFF position, seperating the HOT and LOAD contacts.


If you wired everything properly and you can light the test-light at the head-light sockets, then I do not think the relay is at fault.


Are you using the same old head-light bulbs that were in the truck prior to doing the relay mod ?? were these bulbs working before the relay mod ??


If you changed bulbs, it is possible that a bulb has an internal short-circuit.