TheSamba.com :: View topic

Sun Nov 01, 2009 5:58 pm

Considering that the thermostats for the cooling flaps in the doghouse are so rare, and the mexi replacements fail closed, what about using a solenoid or actuator and a temperature sensor to operate the flaps (Yeah, I know, long sentence)? I do not profess to have any engineering knowledge, but this kind of tech is used everywhere. The temperature sensor and solenoid/actuator would mount where the old thermostat went. The electronics that open and close the solenoid could be placed out of the heat somewhere. Or has this idea already been tried and discredited?

Sun Nov 01, 2009 6:46 pm

vandymachine wrote: Considering that the thermostats for the cooling flaps in the doghouse are so rare, and the mexi replacements fail closed, what about using a solenoid or actuator and a temperature sensor to operate the flaps (Yeah, I know, long sentence)?

RARE? There are at least 10 ads in the Samba Classified for original thermostats. Buy one of those. Why re-invent the wheel? :wink:

Sun Nov 01, 2009 7:13 pm

Rare?

I have a dozen or so used and a few new. They are out there if you look.

Sun Nov 01, 2009 11:40 pm

I saw those, but I was under the impression that they aren't made any more, and being even if they were un used they would still be old and prone to failure. I am only interested in the old style bellows thermostat and not the mexican design (the whole failing closed issue- which would over heat the engine). As far as re-inventing the wheel, well, I won't be calling the inventer's help line any time soon - got too much old paint to scrape off of this thing so it can be painted before winter. :lol:

Mon Nov 02, 2009 5:32 am

vandymachine wrote: I saw those, but I was under the impression that they aren't made any more, and being even if they were un used they would still be old and prone to failure. I am only interested in the old style bellows thermostat and not the mexican design (the whole failing closed issue- which would over heat the engine). As far as re-inventing the wheel, well, I won't be calling the inventer's help line any time soon - got too much old paint to scrape off of this thing so it can be painted before winter. :lol:
You're right, they aren't being made anymore. I have two NOS old-style thermostats in my VW's and they work fine and what's the worst that could happen if they fail?

What's the worst that could happen with some untried electronic thermostat? A fried engine maybe? :x

Mon Nov 02, 2009 5:42 am

I am all for tinkering with electronics. You could use a solenoid with a thermostatic switch and relay easily and fail safe with out frying the electrical system or your motor. Cost wise its cheaper and easier to buy a nos or good working original bellows thermostat, just screw it in.

Mon Nov 02, 2009 6:42 am

Perhaps a small microswitch can be added that will turn on a small LED if the flap is in the closed position. THat way even if the mexican one fails, you would know right away.

Mon Nov 02, 2009 7:13 am

After reading the replies, it looks like the older model looks like the way to go but, that microswitch idea is excellent! I haven't thought of that. The mexi version could be used without any worries there - provided that the switch is put in correctly. Perhaps you could put a light in the dash that says flaps open or something like that.
In closing my thought here, I reasoned in my mind a small electronic control could be thrown together that would be cheaper and possibly more reliable than the two thermostats available now - but after thinking about it, that would add two or three more points of failure (elecronics, actuator, temp sensor). I think I will also try to put a switch in to monitor the status of the flaps. If nothing else it sounds like a fun thing to try. Who doesen't like tinkering? Thanks for all of the good replies! :P

Mon Nov 02, 2009 7:17 am

i havnt bought a vw yet that has a thermostat or flaps on it. all the ones i have bought are always missing those parts. i guess down here in the south, people have removed them for some reason or another. :? :lol:

Mon Nov 02, 2009 7:27 am

superman73 wrote: i havnt bought a vw yet that has a thermostat or flaps on it. all the ones i have bought are always missing those parts. i guess down here in the south, people have removed them for some reason or another. :? :lol:

ignorance and cheapness are the usual reasons.

Mon Nov 02, 2009 7:30 am

rzepko6194 wrote: superman73 wrote: i havnt bought a vw yet that has a thermostat or flaps on it. all the ones i have bought are always missing those parts. i guess down here in the south, people have removed them for some reason or another. :? :lol:

ignorance and cheapness are the usual reasons.
you are probably right. :wink: i have seen some really redneck fixes on these old beetles. :lol: you wouldnt believe some of the stuff ive seen people do to keep their cars going a few more miles.... :roll: