So here’s what I’ve put together.
Refurbished the nylon cam with epoxy.
Using the switch to control three mini relays to avoid the high current in the switch. Amp Meter showing the max current through the relays at max fan speed.
Since the current in the switch is in the 100mA range there should never be any heat that could melt the cam ever again.
Lubricated the cam with silicone to minimize wear.
Relay bank mounted on the back of the AC fan casing.
@Wiggles
@Dick_Wells
Great work Ole… I’ve been working on a similar concept. Found a Company - Smooth-On - that sells materials for silicone mold making and liquid resins for casting new cams. One resin in particular cures to a suitable hardness, even for making mesh gears. It’s other feature is its heat resistant. Currently repairing an existing cam with epoxy then will recast in the resin. If all works out new cams will be a snap to make.
So, yes the switches are repairable. As you’ve done, identifying the problem, finding a fix (relays) will alleviate switch failure in the future. Well done.
Question: What relay(s) did you use (part #) and is each mounted in a relay connector or did you use individual push-on connectors for each wire?
Happy Trails,
Dick
In a message dated 7/19/2020 12:57:19 PM Eastern Standard Time, noreply@jag-lovers.com writes:
Good morning Dick,
Thank you for the kind words.
The relay is prewired and I got it from Amazon (surprise 
).
Directed Electronics 8616 Relay Assembly Mini https://www.amazon.com/dp/B000CJ05WW/ref=cm_sw_r_cp_tai_LqzfFb9ZZZF6A
I have also ordered a 3 step fan control switch, that I think will work as a replacement for our old switch with the relays to handle the current.
For now my AC is working and the new switch is just o make an experiment and to have it as a spare.
Cheers … Ole
Note: I had to fix the title; it was driving my crazy. carry on.
Yes. The original thread took a bit of a turn and it should have been a separate topic.
Thank You, Thank You (that’s 20) – Mr OCD
Bugged you too, huh?
I would have fixed it… but long ago, I lost the ability to be allowed to do so.
As mentioned I searched the interweb (Amazon) for some relays and a switch to replace my current original AC fan switch.
I found the relays as can be see in this post, but I also found a switch that with some diode and capacitor magic will replace the old melted switch and work perfectly with the relay bank that I put together. I did test it, albeit with out the resistor and capacitor included, which is to hold the first relay during switching from Low to Mid and Mid to Hi fan speeds.
The attached diagram illustrate how it works. The total cost i $40.00, which I suspect can be reduced to $25-30 if/when I find the relays at a whole seller.
Do you really need the capacitor? As long as the correct relays hold steady in the different switch positions you should be fine.
Yes and no Bill.
With the original switch no !
With the replacement switch I found, you do. Because the switch I found disengage the “old” connection, before making the “new” connection and the capacitor will hold the voltage on the relay during the transition. If you don’t do it too slowly. The capacitor and resistor can be changed to make the hold time longer if needed. BTW, I still have to play with the numbers to find the right combination.
The diodes are there to emulate the function of the cam in the original switch.
Makes sense ?
