How can I test the dimmer switch outside of the car?

[sixpack_sid]

I have a 68 charger I am trying to get running. . I have an old dimmer switch in a spare dash panel. Is there a way I can check the spare dimmer to see if it works-before putting it in the car? Also, how do I take the dimmer switch out of the dash when it's in the car?

[Chryco Psycho]

use an ohm meter when it is shorted the lights will be brightest & should have zero resistance , the resistance will rise as you involve more of the coil

[68neverlate]

Also, how do I take the dimmer switch out of the dash when it's in the car?

It's a bit of a job... you have to remove the instrument cluster to get at it.  In order to do that, you need to disconnect the speedo cable and the only way to disconnect the cable is to drop the steering column.  Keep pictures as you proceed through the steps... they'll come in handy for the NEXT time you have to go in...   

[doctor4766]

I can drop the A/C ducting to the left outlet and reach my arm in behind the dash to remove or refit the speedo cable.
It can be painful but it can be done

[jaak]

Is the one in your car causing the gauge/dash lights to not work? If so you might want to 'bypass' the dimmer. I done mine (with switch still in car and cluster in). My dash lights would not work, and I figured the dimmer wheel was the culprit. You can bypass the dimmer wheel, by unplugging and using a couple of short pieces of wire, 3 male terminals and 1 female terminal. After bypassing, dash lights worked, and you can use the wheel to turn on dome/courtesy lights, but you can't adjust the brightness of the dash lights (but hey, they aren't too bright all the way up anyways).

Attached is a quick drawing I made, should help you out.

Jason

[sixpack_sid]

Is the one in your car causing the gauge/dash lights to not work? If so you might want to 'bypass' the dimmer. I done mine (with switch still in car and cluster in). My dash lights would not work, and I figured the dimmer wheel was the culprit. You can bypass the dimmer wheel, by unplugging and using a couple of short pieces of wire, 3 male terminals and 1 female terminal. After bypassing, dash lights worked, and you can use the wheel to turn on dome/courtesy lights, but you can't adjust the brightness of the dash lights (but hey, they aren't too bright all the way up anyways).

Attached is a quick drawing I made, should help you out.

Jason

That's a  GREAT IDEA!! I wanted to do something like that but wasn't sure how. I will try this and see if my lights work! Thanks a lot!!

[sixpack_sid]

I was finally able to go in the garage this morning and check out the dimmer switch. I figured out the dimmer switch is bad! Thanks jaak!! That's one problem fixed. More problems listed in other posts!

[Needa68]

Jaak: Thank you for posting the dimmer switch bypass diagram. We had instrument lights and could vary them sightly but even at high intensity they were very dim. We performed your bypass today without removing the switch. Other than for getting my head wedged between the brake pedal and the floor a couple time it was a fairly easy task. The lights are maybe three times as bright as before. I can even see them come on in bright sun light. That's a first! It helps that we replaced the bulbs with LED's when reassembling the vehicle. Again, thanks for a fine solution.

RHM,Jr.

http://www.68dodgerestorations.com/

[Dino]

I can drop the A/C ducting to the left outlet and reach my arm in behind the dash to remove or refit the speedo cable.
It can be painful but it can be done

I got stuck for a while doing that...don't tell anyone...

[doctor4766]

I can drop the A/C ducting to the left outlet and reach my arm in behind the dash to remove or refit the speedo cable.
It can be painful but it can be done

I got stuck for a while doing that...don't tell anyone...

Haha ok

[mopar0166]

so basically using the switch as ground and then jumping the switch portion of the dimmer for the circuit to give direct power, if I was reading the dash wiring diagram right.

I believe its connected with the door buttons

[mopar0166]

Yea I tested it last night, it wont get a good ground, mine is completely for show not . it bypassed and connected the ground to a dedicated ground circuit.  its very happy now.