Aux Fan Temp Switch in Receiver/Drier seized threads

[dieseldan44]

Hey AC gurus,

I was diagnosing my aux fan not turning on. Just got the system charged two days ago.

Shorted the switch and the fan turned on - I must have a bad switch.

Removed one from the parts car. Go to remove the one in the '85 and *snap*....$%&%^@%$^@%^

So I have a R/D with a brass thread stuck into it.

My fix is Im going to file down the surfaces to bare metal and JB weld another temp switch in to the R/D and call it a day. JB weld is thermally conductive so it should be OK.

Is there a better way? Should I consider something else with a lower turn on temp?

dd

[tangofox007]

You could just install a "seasonal" toggle switch.

[1980sd]

As long as you didn't lose charge you could just wire the fan to come on whenever the compressor is engaged.

[rrgrassi]

Luckily, the temp switch port does not need to be in the refridgerant flow.

I had one break off on me like that. It was easy to remove the threaded post for me, as I have over torqued a new one. I wired the fan to be on with the key, until the replacement switch came in.

[Yak]

Penetrating oil (since the snapped end should be exposed to permit in-flow) and then maybe a small drill bit in a hand drill carefully applied. There's not much screw in there, so it may come out with just using the oil and a left-hand bit like an EZ-out.

I also snapped one off by overtorquing and the stub came out pretty easy.

Short-term, for the summer, I'd recommend jumpering the switch. Squirt some oil in there every now and again. Get back to it later. Don't file and JB-Weld until it's a last resort.

[dieseldan44]

Originally Posted by 1980sd

As long as you didn't lose charge you could just wire the fan to come on whenever the compressor is engaged.

Whats the best way?

I didn't over torque the re-install unfortunately - the old bolt is frozen in there and has probably been there for 15 years.

Penetrating oil and the e-z out didn't work. It really felt like a bad idea drilling into a charged A/C system.

[Yak]

Originally Posted by dieseldan44

Whats the best way?

I didn't over torque the re-install unfortunately - the old bolt is frozen in there and has probably been there for 15 years.

Penetrating oil and the e-z out didn't work. It really felt like a bad idea drilling into a charged A/C system.

I did say "carefully." Useless hindsight now, but if you were servicing a system with a 15 yo R/D, why not replace with a $20 or so new one? Assuming the system was opened up for reason or had leaked out.

The wires at the pressure switch also trigger the compressor to turn on or off, so you could tap off there. A drawback there would be if the pressure got too high to shut the compressor off, then the fan would also turn off so you'd lose cooling when you needed it. Maybe on the "supply" side of the pressure switch?

The easiest short term is to just jumper it. Maybe jumper with a toggle switch: summer = on with the engine, winter = off all the time? Others have posted they run a jumpered aux fan year round, in warm climes of course.

[Phillytwotank]

if you are not using the a/c you don't need the fan. fall then winter is soon. whats the condition of you RD? are you running r12? are you leak free otherwise? Maybe you just wanna open the system and replace the RD.

if not then i'd say toggle switch. Just Under the hood. turn it on hot day driving using the a/c.

[dieseldan44]

Originally Posted by Yak

I did say "carefully." Useless hindsight now, but if you were servicing a system with a 15 yo R/D, why not replace with a $20 or so new one? Assuming the system was opened up for reason or had leaked out.

The worst part is I have a new R/D sitting on my shelf at home. I didnt give it to my indy when they recharged my system last friday. Doh.

I'll put in a toggle switch short term. The funny thing is, I tested the temp switch in water and it works fine. I posted another thread about it - it seems my refrigerant is not getting that hot to begin with:

R134a Refrigerant Temperature...need some A/C expertise

I had the system recharged for a road trip to SC. The first time ive ever taken the car to an indy, other than for an alignment.