How to refurbish a 1998 2nd Gen Dimmer Switch

[fast_dave]

This is the 1st tutorial I am re-submitting due to 2nd Gen Forum. This is due to the sudden decision of Photobucket not allowing 3rd Party photo hosting after 12 plus years. All of the photos linked to the original "sticky" are now DEAD! Hence this re-write to keep all the info out there.

I am thankful for all the info this forum has provided me, and I want the information to stay on the Internet due to the fact that 2nd Gen Explorers are still alive and well and no doubt there are going to be more people that can use this information!


How to refurbish a 1998 Dimmer Switch


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 full power 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 – follow forum member MustangP51 thread (with GREAT PICS) through Step 7 – You can see the dimmer switch in the picture, to the right of the headlight switch:

Link: http://www.explorerforum.com/forums...cluster-removal-and-led-conversion-v2.240166/

Dimmer Switch Removed
Dimmer_1 by Fast Dave, on Flickr

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

Dimmer_2 by Fast Dave, on Flickr

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!
Dimmer_3 by Fast Dave, on Flickr


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.
Dimmer_4 by Fast Dave, on Flickr

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 that 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).
Dimmer_5 by Fast Dave, on Flickr

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.
Dimmer_6 by Fast Dave, on Flickr

 

[fast_dave]

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.

Dimmer_7 by Fast Dave, on Flickr

Here's what a few minutes of light sanding accomplished
Alternate between sanding, and wiping down the copper circuit with Isopropyl Alcohol. 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!

Dimmer_8 by Fast Dave, on Flickr

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.

Dimmer_9 by Fast Dave, on Flickr

 

[fast_dave]

Pitting has been removed from Contact Barrels!
Now it's time to get out the "Dielectric Grease"
Obtain Dielectric Grease for the reassembly process.

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

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

Dimmer_10 by Fast Dave, on Flickr

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.

Dimmer_11 by Fast Dave, on Flickr

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

Dimmer_12 by Fast Dave, on Flickr

Closing comments -

Since refurbishing my dimmer switch two years ago, it has worked perfect.

The switch holds the "high" setting, and there haven't been any more occasions of "self dimming" instrument panel lights and the radio display when I travel over rough roads.

NOTE: You cannot use a rubber eraser to clean up the copper pathways. If you look closely at my pics on a laptop or desktop screen, there were actual tracks indented into the copper pathways. The pathways were actually "burned" into the pathways and 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 1500 wet/dry sandpaper.

Take note of the ventilation slots that Ford engineered into the protective cover. This is a high heat part. Heck, the copper circuit paths 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.

You need to use dielectric grease - don't use anything else! When I opened the dimmer switch, the original grease was dried out from all of the heat, and what little was left had hardened and was coated with dust. This switch did an admirable job for 17 years. It's built like a tank, and it's inherent high quality allowed it to be "refurbished" to as good as new.

All in all, two and a half hours to remove the instrument panel cluster removal and the bench time to refurbish the switch, $3 tube of grease, and $3 for pack of 194 bulbs off of EBAY

Now before I hear complaints how much your time is worth, keep in mind that even if you replaced the faulty part with a NEW $65 replacement dimmer switch (at the time of writing the article), you still have the 45 minutes to 1 hour of labor of carefully removing & reinstalling the instrument cluster. While you have the Instrument Cluster out, now is a good time to replace all of the 194 bulbs, as well as remove the Instrument Cluster clear plastic front cover, and with very low pressure air clean out all the dead the bugs and accumulated dust.

 

[CDW6212R]

Well done Dave. This is the kind of care and maintenance that all older vehicles require, to keep them going. The electrical system is usually neglected a lot on older cars. People don't consider how much the current and heat degrades the many many switches and other components, plus the wiring.

Most electronic devices will develop issues after 20 years, capacitors and transistors being likely to go bad. Those are all fixable, but it takes a person with patience and the motivation to dig into the parts to do it. The overhead compass, radios, EATC AC controllers, the message center, CD changer etc, all can be repaired. So expect things like those to need some care, it'd be smart to rebuild them before they fail.

 

[fast_dave]

Thanks for thw "atta boy" CDW6212R!

The dimmer switch is built like a TANK so it can be successfully rebuilt in just a few hours start to finish.

 

[J_C]

Nice how you went the extra mile to post those pics !

 

[96eb96]

mine had bad solder on the transistor leads