Rad Fan Switch

[steve in stockport]

What temperature range are the swithes you are using your top hoses or radiators?

Currently I have a switch at the bottom of my rad and the temp range is low 80's to high 70's, works fine and the fan only runs on for about 20 seconds after a run. Because of the low range the fan is on quite a lot, not a bad thing as it's doing it's job, but if I go to the top hose it will mean it's not on so often when running and therfore might not burn out at an inopportune moment.

 

Currently looking at one that switches fan on at 97 degrees and off at 85 degrees, but not sure if its right as vauxhall use 100 on/95 off in their rads.

 

Steve

[Redspec]

Hi Steve

 

I have just got one of these to try

 

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=661-8284&x=22&y=18

 

It has a switching differential of 3-4 deg C

 

Steve

[fry61]

Take care;the rating states 240volt A.C. & therefore the contacts may have insuficient gap when open (A.C. volts fall to zero 100 times per sec so any spark is self quenching-- D.C. spark will be maintained across small gaps)

[Redspec]

Only using it to switch the earth of the relay so it should be well up to the job but I agree no use for any sort of real DC power.

 

Steve

[speedtripledan]

i use one of these have done for some time now no probs what so ever http://www.s-v-c.co.uk/prod/Thermo-switch.html

[Guest Noddy006]

Hi Steve. I used a top hose mounted switch of similar temp to your possible target. Got mine from CBS. Haynes manual says opening temp for stat should be 85-89C so I guessed at 94/97 C should be about right. So far it has been O.K. and doesn't seem to operate very often except for abit when in hold up on a warm day. I don't seem to lose water even though I haven't got a syphon bottle fitted yet. It has only been on the road since October so it will be interesting to see what its like on a really hot day. HTH Ian H

[Grim]

103 on 98 off for me, seems to be fine. You want something that switches off at a temperature higher than your rad stat - mine opens at 88

[steve in stockport]

Cheers fellas, that was the info I was after, the stat on the vauxhall opens at 92 so the 100 on/95 off switch would be right.

It's the lovely cnc'd set from CBS that I'm looking at fitting

[Grim]

i bought my hose adaptor from ebay here

 

That takes a M14x1.5 fan switch, leaving you the following options (with intermotor part nos.):

 

 

Part No. - A/F - Size Thread - Temp °C

50172 22 M14 x 1.5 87-82

50042 24 M14 x 1.5 90-85/98-93

50041 22 M14 x 1.5 95-90

50173 22 M14 x 1.5 100-95

50040 22 M14 x 1.5 103-98

 

I go the bottom one, i believe it was from a bmw, about a fiver i think!

[steve in stockport]

Cheers Andy, good link, bought one from him, just need to get to the spares shop for the switch

 

Steve