lindatr4 Posted September 24, 2014 Report Share Posted September 24, 2014 I have a Kenlowe fan that is operated by a thermostatic switch installed in the hose between engine and bottom hose of radiator (as sold by Moss) I wish to fit an underdash manual override switch with warning light to advise when the fan is running. Some of you may say "why? when the fan cuts in or out as required automatically" Well, it's all for peace of mind really. Anyways, does anyone have a schematic diagram of the wiring required to achieve this? I understand that I may have to fit a relay? Quote Link to post Share on other sites
Guest ntc Posted September 24, 2014 Report Share Posted September 24, 2014 Here you go Quote Link to post Share on other sites
MRG1965 Posted September 24, 2014 Report Share Posted September 24, 2014 (edited) Hi Lindatr4, as per Neil's diagram all you need to do is effectively put a switch between the two terminals that the thermostatic switch connect to, to provide a manual by pass. You should already have a relay in your set-up ideally. And the earth on the switch will be to provide an earth to the lamp inside, be careful to connect the terminals the right way around on this type of switch otherwise you might have the lamp on all the time Mark Edited September 24, 2014 by MRG1965 Quote Link to post Share on other sites
lindatr4 Posted September 25, 2014 Author Report Share Posted September 25, 2014 Thanks guys for your valuable advice. It transpires that the present setup does not have a relay (oops!) I tend to think that the original installation of the Kenlowe was too simple for its own good. A live feed from the fusebox to the fan, through the inhose thermostatic switch and then to earth. It worked but it cannot be good can it? I understand that these fans can pull 25 amps on start up.....My plan is to fit a 30 amp relay as per Neil's diagram but what gauge/ colour cable is best for this application. I am thinking 3 or maybe even 4 mm? Quote Link to post Share on other sites
RogerH Posted September 25, 2014 Report Share Posted September 25, 2014 (edited) Hi Linda, you appear to have sorted it. Without the relay the in-hose thermostat will take all the fan current. This it can do but it will shorten its life. Have a look at http://www.vehicle-wiring-products.eu/product.php/642/4-blade-relay Roger Edited September 25, 2014 by RogerH Quote Link to post Share on other sites
lindatr4 Posted September 25, 2014 Author Report Share Posted September 25, 2014 Yet more great advice...thanks Roger! Still need some help with the choice of cabling though Quote Link to post Share on other sites
RogerH Posted September 25, 2014 Report Share Posted September 25, 2014 (edited) Hi Linda The same link above does cable. http://www.vehicle-wiring-products.eu/product.php/1021/28-0-30mm-2mmsq-17-5-amp Usually Brown as a 12V supply But I tend to use red and Black for the earth return. You could use the cable in the link or the next size up. The fan will take about 25amps for a few seconds and then go back to 10amps(ish) . You may need some terminals also - http://www.vehicle-wiring-products.eu/section.php/72/1/non-insulated-terminals Roger Edited September 25, 2014 by RogerH Quote Link to post Share on other sites
lindatr4 Posted September 26, 2014 Author Report Share Posted September 26, 2014 Hi Roger Terminals I have by the dozen...it's the good advice I was short of. Something that you appear to have by the shed load! Thanks again. Clive Quote Link to post Share on other sites
AndyC 4A Posted September 26, 2014 Report Share Posted September 26, 2014 Can I just ask about the position of the sensor, should it be in the bottom or top hose or doesn't it matter as long as the fan comes on at the correct temperature? Quote Link to post Share on other sites
stillp Posted September 26, 2014 Report Share Posted September 26, 2014 Mine is actually in the groove around the header tank, where it joins the core. Held on with a twist of wire. Wouldn't suit a concours car, but then neither does a Kenlowe! I've seen too many inserted in the top hose, causing a leak! Quote Link to post Share on other sites
RogerH Posted September 26, 2014 Report Share Posted September 26, 2014 Hi Andy, having the sensor in the top hose works OK but sealing can be interesting but can be done. Have the sensor in the bottom hose (metal down pipe) is a neat and tidy way of doing things and shouldn't ever leak. Simply adjust the thermostat to compensate for position. Roger Quote Link to post Share on other sites
ianc Posted September 26, 2014 Report Share Posted September 26, 2014 A number of the usual suppliers can sell you the metal pipe, which carries the coolant from the bottom of the radiator back to the pump, with a built-in boss for a thermostatic switch, which they can supply, of course. This is very convenient and overcomes the problem of weeping from whichever hose connection might be used. As Roger has mentioned, a relay should be used in order to avoid a hefty current being switched by the thermostat - should the contacts get damaged over time, it's far easier to swap a relay than the thermostat. The original 1970 Kenlowe offering included a little metal bracket, which could be attached to the underside of the dashboard. The bracket housed a manual over-ride switch and a lamp which indicated that power was being fed to the fan (which, therefore, should be running!). Ian Cornish Quote Link to post Share on other sites
North London Mike Posted September 26, 2014 Report Share Posted September 26, 2014 (edited) LNK has a thermo switch in the downpipe. However, in addition to being a safe guard for overriding a failed switch it can also be used to avoid heat soak Switch it on manual just as you join a stationary queue of traffic and it will hold the heat soak at bay and avoid a temp spike as it tries to handle peak temp without normal airflow NB: Not a lover of the 'kenlow' switch so used the existing rheostat switch hole, much nicer (IMHO) Edited September 26, 2014 by North London Mike Quote Link to post Share on other sites
AndyC 4A Posted September 26, 2014 Report Share Posted September 26, 2014 I bought my fan from Kenlowe and came wth a wide thick rubber band which slipped over the radiator tope hose inlett. This band had a groove in it which the capillary tube to the sensor bulb was laid in. The hose is then slipped over it as per normal with the hose clip tightened directly over the band. No leaks or weeps so far and have had it apart a couple of times dealing with thermostat issues. I did wonder if the sensor bulb would restrict water flow as it sits in the radiator inlet but doesn't seem to. Thoughts? Quote Link to post Share on other sites
TorontoTim Posted September 26, 2014 Report Share Posted September 26, 2014 Although I used to have one like Andy's (bulb in the rad inlet, etc.) - which also never leaked, FWIW - the Kenlowe I bought a few years ago has a small rod-like sensor which sits between a couple of the radiator fins, completely outside of the actual cooling system. It seems to work well (although I also seem to be able to "kill" the Kenlowe brains relatively often - I'm on my third in about 6 years and I think it's just died again...). Quote Link to post Share on other sites
MRG1965 Posted September 27, 2014 Report Share Posted September 27, 2014 LNK has a thermo switch in the downpipe. However, in addition to being a safe guard for overriding a failed switch it can also be used to avoid heat soak Switch it on manual just as you join a stationary queue of traffic and it will hold the heat soak at bay and avoid a temp spike as it tries to handle peak temp without normal airflow NB: Not a lover of the 'kenlow' switch so used the existing rheostat switch hole, much nicer (IMHO) hi Mike, I have one of the pipes in my garage ready to fit, but am unsure which of the sensors to fit. I have looked at the moss site and they sell about 5 different sensors all with a different on/off range. Can I ask which ond you chose to fit and if the override gets used much. This morning spookily I was planning to use my infra red temperature toy (from maplins) to see what the temperature of the original metal pipe is at various gauge readings to see what sensor would be the best compromise. Also plan on the manual switch (you never know). But I'd also like you opinion as you have done it already. Mark Quote Link to post Share on other sites
RogerH Posted September 27, 2014 Report Share Posted September 27, 2014 (edited) Hi Mark, when determining what temp range you need for the thermostat you must also consider the thermostat in the top housing that controls water flow. I use a Summer stat (76'C) in the Summer ( ) and a winter stat 82'C in the winter. So an in pipe stat would need to come on after 82' and go off some where lower than 82'. The complication comes in that the rad down pipe may/will run cooler than the top housing. However generally the rad fan is required when the car is stationary. After a few minutes the rad stops cooling so the down pipe gets as warm/hot as the rest of the system. It will cool quicker once on the move. I think I have the 86 on/ 81 off http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=7805 Roger Edited September 27, 2014 by RogerH Quote Link to post Share on other sites
MRG1965 Posted September 27, 2014 Report Share Posted September 27, 2014 Hi Mark, when determining what temp range you need for the thermostat you must also consider the thermostat in the top housing that controls water flow. I use a Summer stat (76'C) in the Summer ( ) and a winter stat 82'C in the winter. So an in pipe stat would need to come on after 82' and go off some where lower than 82'. The complication comes in that the rad down pipe may/will run cooler than the top housing. However generally the rad fan is required when the car is stationary. After a few minutes the rad stops cooling so the down pipe gets as warm/hot as the rest of the system. It will cool quicker once on the move. I think I have the 86 on/ 81 off http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=7805 Cheers Roger. Had over looked the stat in the setup (dohhh, as Hommer would say). Mark Roger Quote Link to post Share on other sites
North London Mike Posted September 27, 2014 Report Share Posted September 27, 2014 Hi Mark In new money its 86 on and 76 off, works fine for me, sits bottom gauge at 185 most of the time Hope that helps Quote Link to post Share on other sites
stuart Posted September 27, 2014 Report Share Posted September 27, 2014 Although I used to have one like Andy's (bulb in the rad inlet, etc.) - which also never leaked, FWIW - the Kenlowe I bought a few years ago has a small rod-like sensor which sits between a couple of the radiator fins, completely outside of the actual cooling system. It seems to work well (although I also seem to be able to "kill" the Kenlowe brains relatively often - I'm on my third in about 6 years and I think it's just died again...). Tim I had the same problem with that type of sensor in a customers car, it went through 3 before Kenlowe Tech department admitted that they didnt think the electronics would stand up to the vibrations in a TR 4 cylinder engine bay. They sent me a Standard capillary bulb type which has run happily ever since.for the last ten years and umpteen thousand miles. Stuart. Quote Link to post Share on other sites
MRG1965 Posted September 27, 2014 Report Share Posted September 27, 2014 Thanks all. Had a play with the infrared temp tester and the downpipe got up to around 90 degrees at a point I'd like the temp gauge never to get to. So looks like 86 on is the one for me. But they are not that expensive so i can suck it and see. Thanks Mark Quote Link to post Share on other sites
Guest Posted September 27, 2014 Report Share Posted September 27, 2014 Pacet fan, guys, Pacet. Is the answer to all your problems. No oldfashioned capilary tube etc. The modern style sensor nicely fits into the special (Moss?) down pipe. Never had any problems with that. Menno Quote Link to post Share on other sites
peejay4A Posted September 27, 2014 Report Share Posted September 27, 2014 Or Revotec. Quote Link to post Share on other sites
Guest ntc Posted September 27, 2014 Report Share Posted September 27, 2014 I have news for you Menno but sorry chap a load of bulls!!!! I have never had the old Kenlow type ever leak or fail in over .... year's read Stuarts post Quote Link to post Share on other sites
Dave Satchwell Posted September 28, 2014 Report Share Posted September 28, 2014 After three attempts with replacement Kenlowe electronic boxes I have also now been supplied with the original type. Why are they still selling these devices which are clearly not up to the job, definitely one for Rogers list, All the best Dave Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.