How to refurbish a 1998 Dimmer Switch

[fast_dave]

For safety, I drive with my headlights on during the day.

The past year I've noticed the dimmer switch in my 1998 Sport wasn't holding on the high setting.

This was exhibited by both the instrument panel lighting & radio readout going from full strength to dim, without me touching the adjustment on the dimmer wheel. Something was obviously not right inside the switch.

So - I priced the dimmer switch at Rock Auto as well as Amazon, and it was $65!

I felt this was way overpriced because the main light switch was only $20.

Then I went on Ebay and found a vendor that sold a "rebuilt" switch for $35.

That gave me the idea that something inside the dimmer switch was replaceable or able to be refurbished

Here's how I began the process to remove the dimmer switch:
LINK: Dead Link Removed

 

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Dimmer Switch Removed

Dimmer Switch Protection Cover Removed
Utilize multiple, small, flat blade screwdrivers to CAREFULLY bend tabs, lifting off the protection cover.

Dimmer Switch Opened Up
Again, utilize your small, flat blade screwdrivers, and carefully lift up the circuit board out of the black plastic case. Go slow as you don't want to break anything!

 

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Backside of Protection Cover Circuit Board

This side of the Circuit Board is the backside of what you see through the protection cover. The Dimmer Wheel has a spring loaded "barrel" that correspondingly rides on the two black curved contact strips on the Circuit Board. Covering the two black contact strips was a coat of dried up & dirty dielectric grease that I wiped off before I took this picture. The two contact strips held up quite well.

Inside of Black Plastic Case
There is a copper circuit pattern on the inside of the black plastic case. This copper circuit is VERY Heavy Duty. They are actually thick sheets of copper which are cast into the black plastic case. The wear and tear on them was noticeable to the naked eye. The dielectric grease was dried out, and there were wear patterns from the two spring loaded barrels (there are 2 spring loaded barrels on the other side of the dimmer wheel).

Begin refurbishing the dimmer switch
Utilize Isopropyl Alcohol (any strength) and a clean rag, and wipe off the dried dielectric grease off of the circuit pattern. Then, obtain a piece of 1500 grit wet/dry sandpaper. We're going to use the sandpaper to clean up the copper circuit pattern strips.

 

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Wrap the 1500 grit wet/dry sandpaper over something flat & square

In my workshop, I have a collection of new wood chopsticks, that I frequently utilize for various cleaning situations. One particular set was a type that you break apart before use, leaving the ends of the sticks with a square edge. I wrapped my wet/dry sand paper over the end, and used it to scrub away at the copper circuit.

Here's what a few minutes of light sanding accomplished
Alternate between sanding, and wiping down the copper circuit with Isopropyl Alchohol. All we're looking to do is to remove the wear and tear pattern that has been burned into the circuit surface. We are NOT trying to remove more copper than necessary!

Clean up the spring loaded dimmer wheel barrels
Years ago I learned a trick from an old timer. He said that when you need an absolutely flat surface to sandpaper on, use a piece of glass. In my workshop, I have a small sheet of glass that I salvaged from an old shop light that went bad. First, I taped some of the 1500 grit wet/dry sandpaper to the glass. Then, I held the wheel flat to the sandpaper, and at the same time dragged & rolled the contact barrels at an angle 157 degrees to 67 degrees, and 22 degrees to 112 degrees. This process removed the pitting on these two wheels (in the picture), and kept them true. I also lightly cleaned up the single contact wheel on the other side of the dimmer wheel.

 

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Obtain some Dielectric Grease
Obtain Dielectric Grease for the reassembly process.

DO NOT substitute another type of grease, as this grease is meant to be used in an electrical application!!!

A tube costs about $5 and will last you for years.

Coat the Copper Circuit and the two black contact strips with Dielectric Grease
Essentially, coat the paths that the copper contact barrels ride on with Dielectric Grease.

Reassemble; Single Barrel goes toward two black contact strips. Dual Barrels go towards copper circuit strips. Press carefully back together

Since refurbishing my dimmer switch, it has worked perfect.
The switch holds the "high" setting, and there haven't been any more occasions of "self dimming instrument panel lights."

In the 10 years I've owned my Explorer, this forum has helped me with problems many times over. So it's my sincere hope this write-up helps someone that has experienced the same problem!

 

[J_C]

Nice writeup, love the pics!

You can clean copper tracks like that with a pencil eraser too and it doesn't really matter if it's dielectric grease because it's not a high voltage/arcing scenario, nor is there rubber that some petrol greases can degrade... but on the other hand, silicone grease is great for dressing rubber trim and vac fittings too so might as well get some and use it here too.

 

[toypaseo]

Wow, nice write-up

 

[fast_dave]

Nice writeup, love the pics!

You can clean copper tracks like that with a pencil eraser too and it doesn't really matter if it's dielectric grease because it's not a high voltage/arcing scenario, nor is there rubber that some petrol greases can degrade... but on the other hand, silicone grease is great for dressing rubber trim and vac fittings too so might as well get some and use it here too.

Thanks for the kudos on the pics!

Yes, you could clean up the copper circuit pathways with a rubber pencil eraser.

BUT if you look closely at my pics on a laptop or desktop screen, in my case there were actual tracks indented into the copper pathways that needed to be removed. You could not only see them, but also feel them when running your fingernail across them. Thus their removal with fine grit wet/dry sandpaper.

On this particular switch, you need to use dielectric grease, as that what was in there when I opened the dimmer switch. The original grease had taken such a hit that it was dried out, as was coated with dust. It did it's job as long as it could

In closing, take note of the ventilation slots that Ford engineered into the protective cover. This is a high heat part. Heck, the copper circuit path that the two barrels roll on are actual copper plates, not a circuit board. The plates exit out of the case and are the "male connectors" for the wire loom plug.

Even though this switch is built like a tank, after 17 years of service, it went on the fritz. Good thing it is built like a tank, as that allowed it to be "refurbished."

All in all, with instrument panel cluster removal and bench time, two and a half hours and .50 in supplies.

Now before I hear complaints how much your time is worth keep in mind that even if replacing the faulty part with a NEW $65 replacement dimmer switch, you still have the labor of carefully removing & replacing the instrument cluster.

 

[chefduane]

If mine goes screwy again I'll do this refurb. But being inherently lazy, when it went south about a year ago I just got some electrical contact cleaner with a red tube (like a wd40 can) and went nuts spraying it inside the housing. I kept exercising the switch as I sprayed. I then sprayed some canned air in to clear it out. Seemed to work as no problems since. Just a temporary fix tho, I'm sure.

 

[fast_dave]

Wow, nice write-up

Thanks toypaseo!

It was "good times" digging around in the switch - seeing how it operated, noting it's strong and weak points, and passing it on to the forum members!

I've always been a firm believer in using pics to tell the whole story

 

[swshawaii]

Excellent tutorial! Agree on the pics, they don't get much better than that. You must have a surgeons hands. Good job.

 

[fast_dave]

Excellent tutorial! Agree on the pics, they don't get much better than that. You must have a surgeons hands. Good job.

swshawaii -

Thanks for the "atta boy"

The Internet, Digital Photography, and Reasonably Priced Latex Gloves have advanced "shade tree" auto repair by leaps and bounds

 

[pegreen]

Awesome write up, this has driven me nuts for a while, I'll be doing this next weekend, how necessary is it to pull off the trim around the gauges? I would imagine taking off the lower plastic and metal below the steering wheel buys you enough room?
Thanks for the attention to detail

Edit: oh almost forgot my original question! Did you see any reason why this switch wouldn't work in a 96? I want the lights off function when the dial is all the way down, I believe this was a feature starting 1998

 

[acoustiplorer]

My dashboard lights would cut out whenever I turned my headlights on. I bought a replacement part from a guy junking his car but I "fixed" mine by moving the dial so that it rested right in the middle of the 'bump' that turns on your overhead courtesy lights.

Now everything works fine, I just don't get courtesy lights when I open my door which i have no problem with.

 

[fast_dave]

Awesome write up, this has driven me nuts for a while, I'll be doing this next weekend, how necessary is it to pull off the trim around the gauges? I would imagine taking off the lower plastic and metal below the steering wheel buys you enough room?
Thanks for the attention to detail

Edit: oh almost forgot my original question! Did you see any reason why this switch wouldn't work in a 96? I want the lights off function when the dial is all the way down, I believe this was a feature starting 1998

pegreen,

You need to remove the radio, trim, and lower metal to perform this re-furb.
Here's a link to a great Explorerforum write up clearly showing what it takes to get to the dimmer switch:
Link: Dead Link Removed


BUT - if you think ahead, you can also do a couple of other nagging maintenance items that have been on your list, but haven't risen in priority.

For example, you can buy a box of Type 194 Lightbulbs off of ebay, and replace all of the speedo gage/ tachometer face bulbs at the same time. I had a couple that were blown out, but replaced all of them since I knew I'd have everything taken apart. Also, I used compressed air and blasted out the accumulated dust that collects at the bottom of the speedo /tach gage assembly, and is seen while driving during the day.

Hope that helps ;-)

 

[pegreen]

Excellent good thinking, I bought 10 led 194sand replaced all interior lights already there are 11 in total including ashtray light and license plate lights. Anyways I'll see how the LEDs look in the gauge too!
Thanks again for the knowledge

 

[delexploder]

Just used this to refurbish the switch in my 98 and it worked , my interior lights wouldn't shut off , now all is working as it should , thanks

 

[fast_dave]

Just used this to refurbish the switch in my 98 and it worked , my interior lights wouldn't shut off , now all is working as it should , thanks

You're welcome - I'm happy that I could give back to the forum!

 

[Mike65]

fast-dave,
I just wanted to thank you also for a great write up. I just did the refurbish on the dimmer switch in my wife's 99 Sport. I will update once I get it installed.
Mike.

 

[fast_dave]

fast-dave,
I just wanted to thank you also for a great write up. I just did the refurbish on the dimmer switch in my wife's 99 Sport. I will update once I get it installed.
Mike.

Hi Mike65,

For the record with regards to other forum members that read this thread in the future;

* What problem was your Ex suffering that made you put the sweat equity into the dimmer switch rebuild?

* Was the internal condition similar to my switch or?

* Was the rebuild a success or?