my 72 delta 88 the dimmer controls power to all 4 lights I click the dimmer off it shuts off all my headlights the dimmer is brand new the head lights are new any ideas

 

All I can suggest is to check voltages at the switch. Would not be the first time someone got a bad switch if its wired correctly.

 

Bad wire or connector between the dimmer switch and the left hand low beam bulb.

- Eric

 

I tested the dimmer its good my next guess in the wiring

 

When you say you click dimmer off all go out? So high beam lights work all 4?
I would start with MDchanic.

 

First, you ARE aware that the low beam bulbs have TWO filaments, one for high beams and one for low beams. The dimmer switch simply has one wire in (blue, power from the headlight switch) and two wires out (brown for low beams, green for high). The single brown wire splits to feed both low beam filaments. The single green wire splits to feed all four high beam filaments.

Have you back-probed the connectors at each headlight and verified that you have power on the brown wires when in low beam mode?

 

the plug on the left side low beam is junk the light flickers unless its just right can that affect the other side

 

It shouldn't, but that is the first place to check for a problem.

Bad spade terminals on both sides are certainly a possibility.

Pop the spade connectors out of the connectors, clean with a wire brush or similar, GENTLY squeeze SLIGHTLY tighter with big pliers, and that may do it.

- Eric

 

would my best be be to replace the dash switch dimmer and harness when the dimmer is clicked to bright all 4 light up when its clicked off all the headlights shut off the dimmer is brand new all the head light bulbs are good

 

Yes and no. The brown wire from the dimmer switch runs to that connector first. There is another wire crimped into the female terminal in the connector that daisy-chains over to the RH low beam. If the plastic connector body is loose, that won't affect this connection to the RH lamp, but if the terminal itself is corroded or otherwise damaged, then yes it can.

Note that while most of the connectors in your car are the common Packard 56 style, the headlight connectors use the larger Packard 59 terminals. You can get those from American Auto Wire among other sources.

This should help with R&R of the terminals.

 

I believe you posted this earlier:
If you tested it, and it's good, then why would you replace it?


- Eric

 

Why? Do you have too much money? If so, send some to me. Otherwise, why do you want to replace parts you claim are good, especially BEFORE you even know where the problem is?

Sorry, but people do this a lot. I simply can't understand the attraction of wasting money and time. Find the real problem using zero-cost troubleshooting THEN replace only what needs to be replaced. Replacing the harness is a BIG DEAL that will likely create more problems if you don't know what you are doing.

 

I tested the brand new 1 I guess that narrows it to the dash switch or the harness its kinda starting to get frustrating lucky my other 2 brights are about as bright as the dims on my moms car so I can still drive at night

 

I already told you that your problem is in the wire or connectors between the dimmer switch and the left hand headlight.

- Eric

 

What "dash switch"? Are you talking about the headlight switch? If so, that's a complete waste of time. LOOK at the wiring diagram. There is only one wire out of the headlight switch providing power to the dimmer. If ANY headlights work, the dash switch is functioning properly.