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**VetteVet** · 07-12-2012, 08:27 AM

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Quote:

Originally Posted by DesertCat

Sorry VetteVet, but that is confusing it... if as he states, all 4 bulbs light when the dimmer is switched to high beam, it simply cannot be anything but the dimmer. Not really! If you read the very first sentence and look at the diagram, it's a GMC and all four lights are supposed to come on, on high beams also the diagrams show the green feed wires going to all four lights from the high beam relay.

If that is not the case, and the low beams never come on regardless of switch position/condition, then you would be correct. That's how I read his post.

Quote:

When I hit my switch the high beams work, which in turn means all 4 of my lights are on. When I hit the dimmer switch nothing turns on. I know the relays are getting 12V from the battery. I used a 30 amp breaker fuse in between the power from the relay to the battery. I know ground is good. I used the light green and tan wires that were running along the driver side underneath the hood and used those to connect to the relay as stated in the wiring diagram.

It would be far easier and quicker to swap relays though...That's what you are doing when you change the tan and green wires to the 85 terminal on the relays.

if the problem reverses then it is a bad relay, It just confirms that the dimmer is good, and the tan wire has power to the relays. if not then check for main power at relay (30), switch power (85) then if those check out, make sure you have continuity from output (87) to the light sockets. Finally, don't forget the relay and bulbs also need a good ground, so check (86) and the bulb sockets are grounded.

All four bulbs come on so sockets are good and grounds are good. The outside lights are dual element so It's possible that the low beam terminals might be bad but they would both have to be bad for both lights to not come on.
It's also possible that both low beam elements are burnt out

The OP needs to clarify what exactly he means by "which in turn means all 4 of my lights are on" Does that mean all 4 light truly do come on, or merely should come on? Unless I read it wrong he said they all come on.