Heater/AC fan switch... source for new ones

When you get the bad connection from the switch failing this way, can it cause the ac to not always work 100%? I noticed the other day I had resistance turning the knob and sometimes the ac light would turn off unless you jiggled the knob. Ever since this first occurred I have had ac that is ice cold sometimes and could be coming out of the vent at 65ºf at other times. Will be looking into this fix before I go looking for replacement hvac controls.

Thanks for the tip - fixed my granddaughter's 98 New Beetle with same problem!
Was exactly as described. Might not have found it otherwise

New beetle fan switch repair

I just fixed my daughters NB fan switch. It still had the round pin that holds the wiper contact, but things must have gotten hot and the pin melted into the plastic of the hub. Fortunately, the knob was still removeable.
I scraped off the copper corrosion on the wiper and the contact surfaces that the wiper hits. I suspect that buildup (or loss of wiper contact pressure from arcing) makes things hot and then there are issues.
Wiper alignment is key when putting it back together. I must have screwed with that for 45 minutes holding the wiper in with my fingers while rotating the control knob to ensure there was enough contact area and contact was actually being made. I then epoxied the wiper in place (switch in the off position).

Since the plastic started to melt around the connector and the connector itself, the fix was just temporary. I ordered another one rather than risk my daughters car catch fire when the contacts corrode/arc and start heating again. I think my fix will last until I can get her car back and 'do it again'.
I was surprised that the fuse did not pop the plastic was dark and melted.

runonbeer said:

Thanks for posting this Andy. It helped immensely in troubleshooting my "no fan" situation.

Here is what he is talking about folks:

when you get the knob and the switch cover off (all three knobs have to come off). You will see this (shown in the zero fan speed position):

Note the "L" shaped piece that has broken out of the "rotor"

The normal position of the "L" is here (shown in the fan speed 3 position):

Note the broken plastic tab on the rotor that the clip on the "L" engages.

Here is how I fixed mine:

I didn't have a lot of time so I just waited about 15 minutes with my shop light sitting near the JB weld and then put everything back together. I just drove to CO over the weekend and the switch is working perfectly.

My 10 year old switch had 235K miles on it. The repair cost me $0. I am very happy.

Click to expand...

Thanks again for posting the info and pics on how to fix this switch. A quick search on here and I didn't even have to spend 1 minute actually diagnosing the problem...lol. It was already done by others.

My switch was broken exactly the same as your pictures. I didn't see any distortion from the heat or anything, just the broken plastic. I am going to fix the original switch, but what I did was grab another non-broken (or is that pre-broken?...lol) HVAC switch module from a junked Beetle, and then I added the JB Weld to strengthen it. The switch cost me $15, so it wasn't a big expense. I'll still JB weld my broken switch and keep it for a spare.

Anyway, my fan speeds are all back in business now. Thanks guys.

Rembrant said:

Thanks again for posting the info and pics on how to fix this switch. A quick search on here and I didn't even have to spend 1 minute actually diagnosing the problem...lol. It was already done by others.
My switch was broken exactly the same as your pictures. I didn't see any distortion from the heat or anything, just the broken plastic. I am going to fix the original switch, but what I did was grab another non-broken (or is that pre-broken?...lol) HVAC switch module from a junked Beetle, and then I added the JB Weld to strengthen it. The switch cost me $15, so it wasn't a big expense. I'll still JB weld my broken switch and keep it for a spare.
Anyway, my fan speeds are all back in business now. Thanks guys.

Click to expand...

Assumption/Question:
I'm assuming you have to take the radio out to pull the entire unit out right??

dlaveen said:

Assumption/Question:
I'm assuming you have to take the radio out to pull the entire unit out right??

Click to expand...

If you're talking about a Beetle, yes. On the Golf and Jetta, I think you can just pull the cover off?...Not sure...

If I remember correctly, you have to remove the radio and radio cage in order to completely remove the unit from the dash.

I think it was possible to remove the knobs and front cover to try the repair with the unit still in the car. It has been a long time since I did this. I also had bad luck with the repair and ended up putting a cheap china unit in from ebay, which I quickly regretted and replaced with a good used unit.

First off, THANK YOU to the OP and others for all the detailed info that helped me diagnose my no fan probably easily. Attached is a picture of the male side of the plug, control box side. I will take a picture of the female side this afternoon as well as the clear plastic piece that goes on the front. As you can tell there was an excessive amount of heat, scary to me the extent of the melting. To my surprise the "L" piece was still intact and my problem was with the burnt terminals on both male and female sides as well as a possible burnt wire on the female side of the plug. My question is what causes this amount of heat, too much resistance I am assuming, but majority of damage was on the top two pins, high speed on blower, which should be 12v correct? I have another control box coming today but wondering if there is something I should check before replacing the unit and risking this again. Thanks again for all the help!

I can't speak for the VW switch, but in 80s-90s Mopar vehicles the fan control switch burns up when the blower fan starts wearing out (which increases the current draw/resistance through the entire circuit). You'll need to see the circuit diagram and see if it is connected to any device such as the fan vs a relay.

The 2000 Beetle I brought home last week actually had a dash fire due to this. I had a very hard time locating a dash "skeleton" (plastic frame) locally to use as a replacement. A lot of work to repair. Also destroyed the "spaceman face" bezel and radio.

I needed to cut the looms open to ensure wiring insulation was not scorched. Oddly enough, they weren't. I only needed to splice approx. 5 inches immediately behind the plugs.

Even more difficult is getting rid of all the "dry" chemical (which is formulated to adhere to everything) (and is a type of grit which works it way into EVERYTHING) which was sprayed by the local "heroic" (guys who sat in the back of the class in school) fire dept. Half a cup (or bladder) of pess would have sufficed.

What a nightmare. Wish I had not brought it home.

Figured I'd add a link here, similar thread w/some Golf in dash repair pics/description.