Adjustable auxiliary fan switch...possible? - PeachParts Mercedes-Benz Forum

Jub · #1 12-21-2013, 01:18 PM

Hi Everyone,

I have been running an auxiliary fan with a manual switch routed to the inside of my car this past summer (heat and DC traffic).

I found a wire which I at first thought was 12V one that hooked up to my automatic choke (have webers). But when I tested the lead i realized that the juice kicks in after the engine warmed up a bit (seems to be the auxiliary fan switch wire).

Anyway, I re-routed my carb chokes to a true 12 V lead (ie, kicks in as soon as I turn the key)....but now this other line I was thinking of hooking up to my aux fan (as it was suppose to be; and disconnect my manual switch). But I really want my aux fan to kick in at 90-95 degrees.

Is there one already set, or does an "adjustable aux fan switch" exist for my 71 w114?

Jub

vandor · #2 12-22-2013, 12:05 AM

There are universal ones you can get from places like Summit Racing.

Jub · #3 12-22-2013, 12:47 PM

Just checked Summit racing, couldn't find it (maybe looked in wrong place).

Would you or anyone know what the standard aux fan switches are set to (ie, what temp are they suppose to turn on).

Maybe I can start there (everytime I look at one on ebay, or even on this website... they just sell them... but never mention what temp they are set too...kind of frustrating

vandor · #4 12-22-2013, 01:59 PM

Search for "adjustable radiator fan switch"
The first thing that comes up is a universal one where the probe pushes between the radiator find and the temp is adjustable 160-210F.

Jub · #5 12-22-2013, 05:26 PM

Yep,

I see it now (thanks vandor).

Thinking I may just hook up my pre-existing one, and see how it goes for a few days.

It looks like it cuts on at around 80.... which would effectively mean that it would just stay on all the time? Maybe I am missing something (I used a meter to see when it stayed on... maybe it gets faster gradually?...ie, 5 V, then 7V, then 12V?).

If all else fails, maybe might hook up one of those summit racing do-hickeys (esp. come next summer).

jimandsuzy · #6 12-30-2013, 08:02 PM

I don't know what your switch looks like but on my 3 cars the fan turns on at 105C and off around 95C. If you have access to a pic-n-pull they're only a few dollars provided they have the same mounting hole. Mercedes stock systems (70s to 80s like mine) are either on or off via a relay.

Jub · #7 12-31-2013, 08:07 AM

Quote:

Originally Posted by jimandsuzy

If you have access to a pic-n-pull they're only a few dollars provided they have the same mounting hole.

Right (both on the same page),

I was in a pic-n-pull in a town called "Mt Airy, MD: Crazy Rays" on Sunday looking for just that. Problem is I couldn't find any cars from the 70's (3 or 4 from early 80's; a 97...slim pick-ins).

It was pouring rain, muddy, no one around except the die hards (and they gave everyone 50% off)....good times! Ended up leaving with some Bose speakers (trying to upgrade the sound), a pocket full of tail lights (can't seem to find a 15W), and an auxilliary fan (mine was making some strange noises).

I hear Texas and Arizona are a gold mine (out here we have to crawl through the mud to get anything)...