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Vintage Jeep Ignition Switch - Part 1: Refreshing An Original Switch

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Part 1: Refreshing An Original Ignition Switch

Image of OEM Jeep CJ5 ignition switch from the 1966 Universal Jeep Parts List:


As noted in the initial thread Moses started based on our off-forum conversations around this issue (When to Restore a Vintage Jeep Ignition Switch), I've recently been experiencing a problem with my 1967 CJ5's original Pollak ignition switch, which is now 50 years old.   Specifically, the switch would sometimes fail to connect on the Accessory (ACC) terminal when in the Ignition "On" position.   The Jeep would start and run normally, but the radio, windshield wipers, and other electrical devices connected to the Accessory terminal would occasionally fail to operate when the engine was running.  

The discovery of this problem led me to wonder if the switch could either be 1) Refreshed, i.e. cleaned internally without actually disassembling it; or if not, 2) Disassembled and rebuilt.   This thread will cover the first of these potential options.

As noted in the previous thread, as I was exploring various ideas, I was referred by someone I contacted online to Scott Versaw, who is an expert restorer of vintage automotive electrical items.  Scott was extremely kind and offered lots of great advice, including the possibility of trying a product line called Deoxit, which he referred to as the "secret sauce" he has used successfully in the past for cleaning closed switches.  

I decided to try that option first, so I bought a spray can of Deoxit D Series cleaner, as well as one of Deoxit S5S Shield (see previous thread for links to these products).  To recap from that thread, Deoxit cleaner is basically a specialized solvent designed to remove corrosion and other contaminants from switch contacts, and Deoxit Shield is designed to be used after the cleaner to protect and lubricate the contacts.   The reviews of both indicate that they are excellent products that are used for many types of electric and electronic device cleaning, including among others ignition switches on motorcycles, aircraft, and many types of equipment.  

To begin the cleaning process, after disconnecting the battery and removing the ignition switch bezel nut from the front of the dash, I disconnected the switch from the wiring harness by removing the wires from one terminal at a time.  I used twist-ties through the wires' ring terminals in order to keep the wires on each contact together, and wrote on masking tape wrapped around each bundle of wires - again, one terminal at a time - to indicate which terminal (ACC,IGN,BAT, or ST) they were removed from so that I wouldn't mix any of them up during reassembly.  

Here's a photo of the base of the ignition switch before it or any of the wires were removed: 



The still-connected switch pulled out from behind the dash (with the bezel nut screwed back on temporarily):



After clearly marking each set of bundled wires and disconnecting the switch, I removed the lock cylinder from the switch housing.  In this particular switch, this is done by rotating the key to the "on" position and using a thin, straight metal tool (like a 1/16" Allen wrench) to press the spring-loaded retainer clip on the lock cylinder through the small hole in the "neck", or lock cylinder socket.  Once this small brass clip (visible below in the center of the lock cylinder) is depressed slightly toward the center of the lock cylinder, the cylinder can easily be pulled out of the housing.  

The photo below shows the lock cylinder upon its initial removal from the switch.  I'm fortunate to have one of the original Jeep logo keys that came with the vehicle when it was new, so I thought I'd digitally immortalize it here:  


I first cleaned and lubricated the lock cylinder as shown below.  

For those unfamiliar with how this type of lock works, as the key is inserted, it moves through five hollow, spring-loaded brass wafers in the cylinder.  These wafers move according to the height (or cut) of the inserted key at each wafer's particular location within the cylinder.  

As it is inserted into the lock, the correct key will move the five wafers so that all of their edges are flush with the outside of the cylinder, allowing it to rotate inside its socket in the switch housing (and turn the ignition switch).  In the "Off" position, as the key is removed from the lock, tiny internal springs move these brass wafers slightly outward to extend below the bottom of the cylinder.  The edges of the extended wafers slide into a longitudinal slot in the lock cylinder's socket in the switch housing, which prevents the cylinder from being turned.  The photos below illustrate this:

1. Lock cylinder with key in;    2. Lock cylinder with key out;    3. Lock cylinder socket showing wafer slots



Over the life of the vehicle, the key being pushed into and pulled out of the lock thousands of times causes wear on both the key and on these brass wafers, resulting in tiny metallic particles gradually building up in the lock cylinder and in the switch.  I suspect that this lock cylinder had probably never been removed during its 50 years in service, as quite a bit of this metallic "dust" had collected inside it.  

To remove this metallic particle dust, I put the lock cylinder in a small container (a clean plastic film canister) of denatured alcohol and moved the key in and out of the keyway over and over again until the metal particles stopped coming out of the cylinder.  Note that the dust removed from the lock cylinder is entirely inside the container (and is not the metal filings you see scattered on the work bench in the photo below):  



The inside of the container after the lock cylinder cleaning, showing the metallic particles that came out of the cylinder:


There was some minor corrosion on the cylinder that needed to be cleaned off, which the denatured alcohol and a wire brush easily removed.  I let the denatured alcohol evaporate, and helped this along by using a can of compressed air (the type used for electronics cleaning) to blow out of the inside of the keyway thoroughly.   Once the lock cylinder was completely dry inside and out, I used an excellent lock lube I keep on hand called Houdini to lubricate the cylinder and wafers ( https://smile.amazon.com/HOUD1-Houdini-Lock-Lube/dp/B00C5JFKKE/ref=sr_1_1?s=hi&ie=UTF8&qid=1483310069&sr=1-1&keywords=houdini+lock+lube ).  The cleaned, lubed cylinder was then ready to reinstall in the switch once it had likewise been cleaned.


One challenge with trying to clean this particular type of ignition switch is that without disassembling it, there are no openings through which to apply a cleaner to the internal parts except the open lock cylinder socket.  Accordingly, I sprayed Deoxit cleaner through this opening, then put the lock cylinder back in so that I could move the key back and forth to hopefully work the cleaner into and through the internal parts of the switch.  I repeated this several times, and eventually, dirty (gray) cleaner fluid leaked out between the plastic terminal base and the diecast metal housing.  

I kept repeating the process until the cleaner fluid that was leaking out became clear.  Note the white paper towel placed just below the switch, which I changed out with each spray-and-rotate cycle in order to assess the color of the cleaner fluid that was leaking out each time.  (Note also that you can barely see the edge of the small hole through which the lock cylinder retainer clip is released just below the threaded neck toward the right side):




The instructions indicate that the Deoxit D5 cleaner needs to evaporate completely before the application of Deoxit Shield.  Since the switch was closed, I figured the evaporation process would likely occur very slowly.  In order to hopefully accelerate this, I hung the switch upside down suspended with twist-ties in front of a warm air supply vent for several days to allow it to drain and/or evaporate thoroughly:


After letting the cleaned switch dry for several days, I applied Deoxit Shield in the same way I'd used the cleaner previously.  After spraying it into the lock for a few seconds, I reinstalled the lock cylinder and rotated it back and forth with the key to work the sprayed liquid into the internal switch parts.



After the Deoxit Shield had dried, I tested the electrical continuity of the switch.  The initial problem with the switch had been an intermittent connection between the ACC terminal and the IGN terminal.  Using a continuity tester, I rotated the switch through its various positions, checking this connection probably 40 times.  

And....drum roll, please....

It failed.

Though the intermittent connection / resistance problem at the Accessory terminal was definitely better after cleaning than it had been beforehand, the problem did not vanish entirely.  Twice during this testing, the ACC terminal failed to connect with the IGN terminal as it should have.  This represented about a 60% reduction in the failure rate experienced before the switch was cleaned.  

Had the switch been in better shape internally, I suspect the Deoxit products may very well have done the job.  However, the degree of wear, corrosion, and/or burned contacts present in the original switch after 50 years of use was evidently too great for the "Deoxit Process" to succeed completely (though it did help).   

Rather than reinstall a switch that clearly still has a problem, I decided to try rebuilding it altogether, which I will cover in another thread ( Vintage Jeep Ignition Switch - Part 2: Rebuilding An Original Switch ).   


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