johnwill Posted July 12, 2021 Report Share Posted July 12, 2021 (edited) Looking for help again.... I have a Kenlowe Fan, with also a manual switch. I'm not convinced it's wired correctly, but I have seen lots of advice on here about fitting a relay. So, can anyone advise the correct connections for the wiring to the relay please, or any isses with current set up? (I think something is wrong, as when i have the manual switch on, and turn the ignition swith off, the engine keeps running.....well, it did once, i've never done that since) The Power to the Thermo switch is taken from the Horn relay, The manual switch from the fuse box. Edited July 12, 2021 by johnwill Quote Link to post Share on other sites
RobH Posted July 12, 2021 Report Share Posted July 12, 2021 (edited) Yes connected like that the un-switched live from the horn circuit will go via the kenlowe unit and the manual switch to the rest of the car, so it will bypass the ignition switch. You can cure that by taking the manual switch feed from the same point on the horn relay (C2) rather than from the fuse box. As it stands the fan circuit is protected by the in-line horn fuse. As it is shown, your cooling fan will continue to run after the ignition is turned off, until the engine cools down. I assume you want to retain that. This is how to add a relay with the minimum of changes, which will take the load off the manual switch and the Kenlowe unit. The numbers are for a modern relay. (Rather than using the horn feed it would be better to have a separate fused connection though. There are a number of threads with suitable circuits if you do a search)) Edited July 12, 2021 by RobH Quote Link to post Share on other sites
johnwill Posted July 13, 2021 Author Report Share Posted July 13, 2021 17 hours ago, RobH said: Yes connected like that the un-switched live from the horn circuit will go via the kenlowe unit and the manual switch to the rest of the car, so it will bypass the ignition switch. You can cure that by taking the manual switch feed from the same point on the horn relay (C2) rather than from the fuse box. As it stands the fan circuit is protected by the in-line horn fuse. As it is shown, your cooling fan will continue to run after the ignition is turned off, until the engine cools down. I assume you want to retain that. This is how to add a relay with the minimum of changes, which will take the load off the manual switch and the Kenlowe unit. The numbers are for a modern relay. (Rather than using the horn feed it would be better to have a separate fused connection though. There are a number of threads with suitable circuits if you do a search)) Thanks Rob. Looking at your diagram, if I just take the red wire off the horn relay, and extend it to double up with the switch red to the fuse box, that will sort it? Would It be better to include an inline fuse as well in that case, or unnecessary? Quote Link to post Share on other sites
RobH Posted July 13, 2021 Report Share Posted July 13, 2021 If you do that the fan current is taken by the ignition switch which is not a good idea and rather defeats the idea of the relay John. That circuit was just a way of changing yours with minimum effort - it is protected by the in-line horn fuse which is a high-current circuit anyway. The best thing to do would be to re-hash it completely with a separate fused feed but it will take a while for me to draw it - though as I said there are circuits in previous threads. Quote Link to post Share on other sites
johnwill Posted July 13, 2021 Author Report Share Posted July 13, 2021 Just now, RobH said: If you do that the fan current is taken by the ignition switch which is not a good idea and rather defeats the idea of the relay John. That circuit was just a way of changing yours with minimum effort - it is protected by the in-line horn fuse which is a high-current circuit anyway. The best thing to do would be to re-hash it completely with a separate fused feed but it will take a while for me to draw it - though as I said there are circuits in previous threads. I’ll go search on here, see if I can find it thanks again John Quote Link to post Share on other sites
RobH Posted July 13, 2021 Report Share Posted July 13, 2021 (edited) I've just had a quick search and can't find anything useful. Murphy's law - I'm sure there is one. Hang on and I will draw it: This arrangement as shown will turn the fan off with the ignition. If you want the fan to stay on afterwards until the engine cools then just link 30 to 85 on the relay through a 5 A fuse and omit the green wire. The unswitched supply should really be taken from the downstream side of the ammeter, so the fan registers as a load. If you still have a dynamo then use A1 on the regulator box. (it also assumes your kenlowe switch is the electro-mechanical capillary bulb type which requires no power of its own) Edited July 13, 2021 by RobH Quote Link to post Share on other sites
Graham Harris Posted July 13, 2021 Report Share Posted July 13, 2021 This will fix it Quote Link to post Share on other sites
harlequin Posted July 13, 2021 Report Share Posted July 13, 2021 (edited) On my TR3 I found the simplest way was to have the manual and thermo switches toggling the relay earth rather then the live circuit George You beat me to it Graham Edited July 13, 2021 by harlequin Quote Link to post Share on other sites
johnwill Posted July 15, 2021 Author Report Share Posted July 15, 2021 On 7/12/2021 at 5:32 PM, RobH said: Yes connected like that the un-switched live from the horn circuit will go via the kenlowe unit and the manual switch to the rest of the car, so it will bypass the ignition switch. You can cure that by taking the manual switch feed from the same point on the horn relay (C2) rather than from the fuse box. As it stands the fan circuit is protected by the in-line horn fuse. As it is shown, your cooling fan will continue to run after the ignition is turned off, until the engine cools down. I assume you want to retain that. This is how to add a relay with the minimum of changes, which will take the load off the manual switch and the Kenlowe unit. The numbers are for a modern relay. (Rather than using the horn feed it would be better to have a separate fused connection though. There are a number of threads with suitable circuits if you do a search)) Rob, so least work is as above, but better route is as below? I think it follows both your's and Graham's suggestions. What size fuse in the main supply to pin 30? I have an Alternator, so no regulator box, and the fan does run on after ignition swtiched off. John Quote Link to post Share on other sites
RobH Posted July 15, 2021 Report Share Posted July 15, 2021 Yes that will do fine John. The feed to the horn relay (pin C2) is already fused - there will be an in-line fuse in the loom near the horn - so if you are intending to use that point as the feed there is no point in fitting another. If you use a separate feed though, a 25A fuse should suffice. Conventionally you ought not to use red as the wire colour from the relay to the switches - since they go to earth they ought to be black but I guess as long as you make a note of the new arrangement for future reference all will be well. Quote Link to post Share on other sites
johnwill Posted July 15, 2021 Author Report Share Posted July 15, 2021 46 minutes ago, RobH said: Yes that will do fine John. The feed to the horn relay (pin C2) is already fused - there will be an in-line fuse in the loom near the horn - so if you are intending to use that point as the feed there is no point in fitting another. If you use a separate feed though, a 25A fuse should suffice. Conventionally you ought not to use red as the wire colour from the relay to the switches - since they go to earth they ought to be black but I guess as long as you make a note of the new arrangement for future reference all will be well. Thanks Rob, and everyone else, for your help Quote Link to post Share on other sites
johnwill Posted July 25, 2021 Author Report Share Posted July 25, 2021 On 7/15/2021 at 7:49 PM, RobH said: Yes that will do fine John. The feed to the horn relay (pin C2) is already fused - there will be an in-line fuse in the loom near the horn - so if you are intending to use that point as the feed there is no point in fitting another. If you use a separate feed though, a 25A fuse should suffice. Conventionally you ought not to use red as the wire colour from the relay to the switches - since they go to earth they ought to be black but I guess as long as you make a note of the new arrangement for future reference all will be well. All done today following your suggestions. a question though I have a warning light on my switch that now still comes on, but very dim when I turn the fan on manually. Is this just a consequence of this being an earth route now, or something else? thanks john Quote Link to post Share on other sites
RobH Posted July 25, 2021 Report Share Posted July 25, 2021 (edited) Ah - you didn't show that lamp in your original diagram - it complicates things a bit. If the lamp is internal to the switch it will be wired expecting the switch to be in the live supply rather than the earth line, so now it isn't getting enough power to work because the current is coming via the relay coil. It might be possible to re-arrange things so the lamp works, but not possible if the earth connection for the lamp is made directly through the switch mounting arrangement. Do you know the switch details or do you have a picture of it? Is the lamp a conventional bulb or an LED? Edited July 25, 2021 by RobH Quote Link to post Share on other sites
james christie Posted July 25, 2021 Report Share Posted July 25, 2021 (edited) Sorry to come in a bit late on this thread I had some exchanges with Kenlowe in April about this very problem. My over ride switch has an incandescent bulb. Clearly they had to delve deep into their archives as I fitted my Kenlowe in the late 80s or early 90s Attached is the diagram they sent me and also the switch on my car that it refers to. james Edited July 25, 2021 by james christie Quote Link to post Share on other sites
RobH Posted July 25, 2021 Report Share Posted July 25, 2021 You can't really do anything if the lamp is an LED and the switch is in the earth line, as the 'fix' is to reverse the lamp polarity so it is wired to supply instead of to earth - but an LED only works one way round. It would be possible if the lamp is an incandescent bulb but again only if the lamp connection is made via a wire and not through the switch body : Quote Link to post Share on other sites
johnwill Posted July 25, 2021 Author Report Share Posted July 25, 2021 (edited) Just checked my online orders, and found it. DURITE 059705 SWITCH PUSH PULL SWITCH ON/OFF SINGLE POLE FITTED WITH 12 VOLT BULB FOR RED ILLUMINATION 2 X 6.3MM BLADE TERMINALS 13MM DIAMETER PANEL HOLE REQUIRED 10 AMP AT 12 VOLT DC RATING THE SWITCH CAN BE USED ON 6 VOLT 12 VOLT OR 24 VOLT (by changing the bulb) I think there is a clue in there.... Edited July 25, 2021 by johnwill Quote Link to post Share on other sites
james christie Posted July 25, 2021 Report Share Posted July 25, 2021 John , I have sent you a PM james Quote Link to post Share on other sites
RobH Posted July 25, 2021 Report Share Posted July 25, 2021 (edited) John - that Durite switch seems to connect the earthy side of the lamp through the switch mounting arrangement rather than through a separate wire. Unfortunately that means the alternative connection I showed in the post above will not work. Your options are either to fit an alternative type of illuminated switch with a separate connection, or to remove/ignore the lamp from the one you have and fit a separate warning lamp. Edited July 25, 2021 by RobH Quote Link to post Share on other sites
james christie Posted July 25, 2021 Report Share Posted July 25, 2021 Robh l am almost certain that this is so on the Kenlowe switch illustrated above. james Quote Link to post Share on other sites
johnwill Posted July 25, 2021 Author Report Share Posted July 25, 2021 1 hour ago, RobH said: John - that Durite switch seems to connect the earthy side of the lamp through the switch mounting arrangement rather than through a separate wire. Unfortunately that means the alternative connection I showed in the post above will not work. Your options are either to fit an alternative type of illuminated switch with a separate connection, or to remove/ignore the lamp from the one you have and fit a separate warning lamp. I assume I could just leave it as is, with a dim light? Quote Link to post Share on other sites
RobH Posted July 25, 2021 Report Share Posted July 25, 2021 Indeed you could. A light is probably a bit OTT considering the racket the fan usually makes. Quote Link to post Share on other sites
johnwill Posted July 25, 2021 Author Report Share Posted July 25, 2021 26 minutes ago, RobH said: Indeed you could. A light is probably a bit OTT considering the racket the fan usually makes. It seemed like a good idea at the time Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 27, 2021 Report Share Posted July 27, 2021 (edited) Consider yourself lucky. My original fan set up (windscreen wiper motor, Escort plastic fan, bit of Mecano, etc. Almost E Type!) with only a manual switch and no relay shewed the warning light bulb ‘on’ when switch on, and glowing with differing intensity when switched off but driving above 30 mph. The faster I went the brighter the light. My very own on board wind generator system. Peter W Edited July 27, 2021 by BlueTR3A-5EKT Quote Link to post Share on other sites
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