Electrical gurus needed..........

[koosh]

I have no dash lights, UNTIL- I turn up the brightness wheel all the way to dome light on???
The dome light does NOT come on at this point, but works perfectly when doors are open....
ideas?

 

[BeepBeepRR]

I would suspect that switch is on its way out. Its a rheostat style and must not be making contact with the bimetal spring. You may want to take it out and try cleaning the contacts that touch the spring.

 

[65-440]

What he said ....

 

[dadsbee]

As pointed out it's your dimmer rheostat. You are dealing with 2 circuits here. The dash light circuit is variable resistance as you roll the wheel and the dome light is turned on when the wheel is turned all the way and engages a contact to GROUND. Meter shows this happening 0.00 ohms from frame to upper connector lug.

 

[FrnkNsteen]

I have no dash lights, UNTIL- I turn up the brightness wheel all the way to dome light on???
The dome light does NOT come on at this point, but works perfectly when doors are open....
ideas?

You have two things going on.....

The first is what Beep said about the contacts not contacting the bi-metal spring. That is what gives you the ability to change the brightness of the lights. When the contact (copper rectangle in the pic above) reaches the end of the spring and goes up on that brass, you have no resistance and should have full brightness. You need to clean the spring and that copper contactor with electrical parts cleaner. I use DeOxit (think that's how its spelled).

The dome light issue is controlled differently. There is a little copper arm attached to the switch case. The white wheel has a raised cam that contacts the small copper spring and grounds it to the case. You need to clean all the contacts so when the cam pushes the copper spring against the post of the case, it makes good ground and turns the dome light on. When you are done cleaning it, you should be able to test it by using a continuity tester with one probe on the case, and the other on the spade terminal marked "D". I use a Fluke Volt Ohm Meter (VOM) set to Continuity, so it beeps if I get connection. If everything is good, it will beep when you roll the wheel up into the dome light position.

The dome light has constant power and is just waiting for ground. The cam pushing the small copper spring against the case provides that ground and turns on the dome light. Your dome light is working with the doors open because the door switches are providing ground to the dome light.

The switch shown above is for '69 and older. They changed the design in '70. I will attach a couple pictures from when I did mine. You can find how I got mine working in my restoration thread (Link Below). My '69 switch was bad and the spring had come loose. I could have reattached it, but pulling it apart needed rivets to put it back together, so I used the '70 model I had. First picture below shows the difference between the two. The second picture shows the little copper grounding spring and the cam on the '70 model. I inserted a couple red arrows to show the cam pushing on the spring, and the spring contacting the case.

https://www.forbbodiesonly.com/mopa...-charger-project.146776/page-2#post-910935154

 

[FrnkNsteen]

As pointed out it's your dimmer rheostat. You are dealing with 2 circuits here. The dash light circuit is variable resistance as you roll the wheel and the dome light is turned on when the wheel is turned all the way and engages a contact to GROUND. Meter shows this happening 0.00 ohms from frame to upper connector lug.

Yep! Nice pics Dadsbee! Only ones I had were the ones I uploaded to my thread. Dadsbee's is the '70 version also.

 

[FrnkNsteen]

Here's another angle showing the contactor in full brightness position (you can see the contactor on the full brightness pad), and you can see the copper dome light ground spring on the right.

 

[Ranger16]

Had a similar problem with mine. The spring was rusted out. Tried to replace it to no avail. I just replaced it.

 

[dadsbee]

Yep! Nice pics Dadsbee! Only ones I had were the ones I uploaded to my thread. Dadsbee's is the '70 version also.

NOT.. mine is a 1969 model. Feb 1969 to be exact and identical to another spare '69 rallye panel I have.

Maybe the RR with standard panel got a different style than the Dodge Rallye panel.

 

[koosh]

Thanks for all the help!!!!

 

[65-440]

Take it out of the car, soak it with battery terminal cleaner then dunk it in a pot of boiling hot water. It'll get most of the crud off it. You can disassemble it to clean but you'll need really small machine screws to put it back together.... not impossible... please post your results once you've got everything back together !

 

[Wietse]

I had the same story, I cleaned the assembly with electrical contact solvent.
After had mini wire brush on my Dremel and polished all contacts and the spring, after cleaned it again with solvent.
Now works perfect!

 

[koosh]

Never ceases to amaze me (albeit i am newbie here) , how much help this forum provides.....tore into the switch today, cleaned it up and now works like a charm....u guys are great!!!

 

[FrnkNsteen]

Never ceases to amaze me (albeit i am newbie here) , how much help this forum provides.....tore into the switch today, cleaned it up and now works like a charm....u guys are great

Good idea on the emery board to clean that contactor! I hadn't thought of that.