Dash Map Light Repair Option: 68 Satellite

[VitaMeVas]

If your OE Dash Map Light looks like this. Keep reading.

I was rewiring my 68 Satellite (using AAW Classic Update Kit) and the attachment for the yellow door wires and black ground for the slide switch crumbled in my hands. I was then left with a metal housing and no switch. You can either buy one off eBay, find a NOS, find the correct switch for it, OR... I made my own using a slide switch from Ace Hardware. It requires some soldering, epoxy, and wiring. Did I do it right? I think so, but I'm sure people will chime in with whatever I did wrong.

**ATTENTION** I messed this up (huge surprise, I know). If you want to skip ahead to the correct way to do this, skip ahead to post #12. If you want to see me mess up twice and laugh at me, just keep reading. ENJOY!!

 

[VitaMeVas]

I went to all the hardware stores and some lamp stores looking for something...anything....that would work. Finally, I found this little gem for $7 at Ace Hardware. It was by the switches and lamp slide out bins (parts section). It's not perfect, but I think it may work.

Here's the packaging from it. It's a '2 position slide switch'. It's designed for 'up to' 125 volt (AC), 6 Amp use. Therefore I believe it should be fine in 12 volt DC work. I believe that you can't use a 12 volt DC in a 125 volt AC situation because it's not able to handle the voltage/amperage. But I think this will work so I'm trying it.

Here's the diagram I found for the way it works.

There are 6 terminals on the bottom of the switch. The easiest way for me to think of it is split the domino down the middle (long way) and each side can be a switch. The center terminal gets wired to the ground (black is OE, white in the AAW harness). Then you just pick one of the outer terminals and make that the link to the yellow wires that come from the door jams. You can wire this particular switch correctly 4 different way. 2 ways on each split of the domino. Here's where people will comment on this so I don't have to. And yes....finding a 3 terminal switch would make it simpler, but this is what I could find at Ace Hardware.

 

[VitaMeVas]

Here's where we do a little grinding. The body of the new slider switch is a little wide for the OE area. So I used a dremel and nibbled away at the inside space where the switch lays. I took less then 1mm off each inner side so the switch would clear but be tight. And when I flipped the switch up and down, it perfectly matched the OE rectangular hole that the black switch sticks out through. Once I got the fitment right....I glued it in place with some quick setting (metal rated) JB weld epoxy. I clamped it in place with some aluminum foil over the JB weld so I could get my clamps back off. I came back 6 hours later (after it cured) and took it apart. The JB weld held great and the aluminum foil was permanently glued to the switch also (only the inside). You have to be careful not to use too much JB weld or it could ooz out into the switch and keep it from operating. Then I soldered a black jumper wire to the center terminal and a yellow wire to the outer terminal (just pick one) and let it cool. I slathered the terminal in black wire insulation goo and after it dried, put black heat shrink insulation over the two wires. I crimped on a bullet terminal to the yellow wire, and a spade to the black wire. I heat shrink insulated these and covered the tips in dielectric grease. Here's the mess I ended up with.

Above you can see where the foil was glued to the body of the switch and the black on the terminals is insulation painted on.... not me burning the terminals with my crappy soldering skills. I tested it with a voltmeter and all seemed to work (just checked resistance).
When I flipped over the switch it looks like this.

Good enough for me.

 

[VitaMeVas]

I mated it to the AAW wire harness and checked for clearance. All was good. Now I just need to find a #90 bulb to test it out.

Maybe this will blow up in my face, but I tried. I wrote this up for someone else who can't find or afford a 'new to them' map light switch AND for me if I want to remember what the heck I did AND probably for the insurance company to evaluate the "cause of the fire". Best of luck to everyone out there. Criticize away....I'm waiting.

 

[oldbee]

Good job, well thought out.

 

[Fran Blacker]

A helpful post for a good cheap fix. Use wax paper if you don't want a clamp to stick to glue.

 

[AMX364]

Cause of fire will almost always be related to cracked fuel line. Lucas, the dark lord does not play with Mopars. When the wiring goes, it almost always quits running. Unless the alternator blows up while driving.

 

[VitaMeVas]

A helpful post for a good cheap fix. Use wax paper if you don't want a clamp to stick to glue.

Ha! My wife said the same thing AFTER I clamped it in place.

 

[Dennis H]

Can’t understand why mine still works.

 

[VitaMeVas]

WELL CRAP!!! Yesterday I learned a lot about the Map Light harness. And...in retrospect, I should've done my homework and figured it out, but on Try#3... Nailed it!! Follow along or skip ahead to "THE RIGHT WAY".

When I hooked up the battery and got a #90 Sylvania Bulb.....it worked....kinda. The map light would come on when the doors were open and shut off when the doors closed, but when I flipped the switch... it would only turn off. I remembered being able to turn on the map light independently with the doors closed...so I looked through the 'B Body Archives' for a reason. As some have guessed.....I didn't have the 3rd terminal of the slide switch grounded to the body. So... a quick scrape and solder with a second black wire and ring terminal and viola!

Just ground the switch and it should work! Hooked it all up ... and ..... "strike 2"!!!

The light still worked when the doors opened and closed, but when I flipped the switch, the under dash/interior system lighting was energized. Nothing smoked/popped/broke.....but I immediately knew what I had done wrong. Explanation next.

 

[VitaMeVas]

EXPLANATION: As I understand it, the light bulb receives energy through having BOTH the positive and negative connected. However, instead of controlling the positive end with a switch... this circuit has the switch on the negative side (or ground). By breaking the ground with the switch, the light bulb is turned off. Like below.

So...when the switch is pushed to one side it grounds the system and completes the circuit when the doors are opened and closed (left direction above). I think it does this by completing the circuit through the door switches (as the yellow wires are a ground-closed system also. And when the switch is slid to the right, the bulb is immediately grounded and turns on constantly (ie using the map light with the doors closed).
I'm sure there are much better and technical ways of explaining it, so here's where people will chime in with links and comments that explain this much better-er. **insert here**

 

[VitaMeVas]

THE RIGHT WAY.

Ahhh...so you've jumped ahead to see how's it's done 'correctly'. Pay no mind to my mental frustration and aching back and bleeding fingertips. FINE. The easy explanation is BLACK-YELLOW-BLACK for the switch terminals. Put the door controlled system ground (yellow wires) in the center terminal and put the black wire ground from the door controlled system on one side (ie flip post #3 above). Then place the other black wire ground with the ring terminal on the other outer terminal. This ring terminal will be grounded to the dash through this black wire (see below).

THERE....now the bulb is 'on' when the doors are closed, 'off' when the doors are open, and 'on' when the switch is slid to the other side (constant 'on'). This is the way I got it to work. And thinking through it, it makes sense now and I should have gotten it right the first time.....but NOPE. **insert criticism here** Like a monkey....I just kept changing things around until it worked or blew up in my face.

So....there ya go, kids. Buy a switch that is over-rated for this DC system, custom grind it's A$$ so it fits in, JB Weld it in place, and lastly solder 3 of the 6 terminals in the correct orientation. When done, I think it looks legit and works well. When it fails, I will update this thread. If it doesn't or the switch breaks from me repeatedly soldering it, I'll replace it with version 2.0 (I bought 2 more slide switches from Ace Hardware as backup).

Well, that was my 'journey' on the map light switch. Everything is working as I wanted, it just took more time and way more patience than I had planned on. PEACE OUT!!!!