spillman Posted April 9, 2020 Report Share Posted April 9, 2020 Greetings one and all. I hope you are all coping well in these troubled times. I am taking the opportunity to "sort out" the Kenlowe fan on my 3A. The year before last it performed fine. Last year I noticed that it was not cutting in at all, even with elevated engine temperature, but it caused me no trouble and I sailed onthrough the season. With some time to spare (!) yesterday I used my multi meter to check the condition of the control unit, and decided it was busted! I connected power direct from the battery to the fan, to confirm the fan was OK. It worked fine. So I had a look online for a direct replacement for the control unit (Kenlowe Variomatic). Nothing available apart from generic units. In thinking the situation through I decided that a simple on/off switch connected to the fan would allow me to operate it when required, based on what the temperature gauge was showing, and do away with the control unit all together. Is there anything wrong this this folks? Today I set about doing the wiring. I found a spare live (with ignition off) connector as part of the loom under the carbs. I connected into this and fed a wire through to the dashboard, and connected to one side of the switch. I connected a wire to the other side of the switch, fed it down to the live cable to the fan, having disconnected it from the broken control unit. When I tested the fan direct before the job today, I had a wire direct from the battery positive terminal to the supply to the fan, and a wire direct from the negative terminal to the yellow wire (earth presumably) and the fan wizzed! However today, when I tried to connect the yellow wire to an earth point, the fan does not go. This includes the earth strap engine to chassis, and other earth ;locations which I would have expected to work. I find my self in a situation where a little knowledge is perhaps worse than no knowledge! Am I doing, or not doing, something stupid? I hope I have explained my predicament sufficiently well to make some sense. Your thought and comments, would be much appreciated. Many thanks John Quote Link to post Share on other sites
RogerH Posted April 9, 2020 Report Share Posted April 9, 2020 Hi John, did you make a drawing to scribble against. A;ways handy to see what you intend. But the basic layout would be - Battery, Fuse, Switch, fan, earth. simples. If the fan sucks instead of blows then swap its wires over. Roger Quote Link to post Share on other sites
RobH Posted April 9, 2020 Report Share Posted April 9, 2020 (edited) Well firstly it is worthwhile checking that the live connection you 'found' is capable of carrying the fan current John. Fans can be a bit power-hungry and take a lot of current particularly when starting up. Perhaps your connection came by way of a fuse which has now blown? The wire itself needs to be of a suitable size too. Your description sounds to make sense but as Roger says a sketch would make everything clear. Nothing wrong with manual switching. Simple and foolproof, but I would personally connect it by a separate fused circuit. Edited April 9, 2020 by RobH Quote Link to post Share on other sites
John McCormack Posted April 9, 2020 Report Share Posted April 9, 2020 I have had a manual switch electric fan on my daily driver TR2 for 44 years. I put one on the TR6 as well although it still has its engine driven fan and I haven't had to use the electric one yet, except to check it is working. You get used to knowing when the fan is needed. I have seen too many automatic switches fail and the driver is used to not monitoring the temperature and driving situation. Cooked engines have resulted. Quote Link to post Share on other sites
Ralph Whitaker Posted April 10, 2020 Report Share Posted April 10, 2020 Hi John, you say you found a wire under the carbs that was live with the ignition off??. Only wire I can think this must be is the live feed to the horns , everything else should be dead. Sounds like when you connected it it blew a fuse somewhere, does everything else still work? I would remove the wire you spliced in there, and take the feed to the fan switch either direct from the battery with an in line fuse, or from a spare terminal on the fuse box, again from the side that is live before it goes through the fuse, and again give it its own in line fuse. Hope this helps, Ralph. Quote Link to post Share on other sites
Ralph Whitaker Posted April 10, 2020 Report Share Posted April 10, 2020 Another thought, what`s wrong with using the existing power supply that supplied the Kenlowe fan, why search for another. Quote Link to post Share on other sites
spillman Posted April 11, 2020 Author Report Share Posted April 11, 2020 Hello Folks and Happy Easter! Many thanks to Roger, Jon, Rob and Ralph for your very useful contributions. Sorry I have not replied sooner, but have been working on and off on the problem most of yesterday....and I thought I had it fixed.......think again! I took onboard the various suggestions, and along the way managed to confuse myself a few times, until I realised belatedly that I was confusing myself in not allowing for the positive earth polarity. No wonder I was getting unexpected readings from the multi-meter. It was so bleedin' obvious I could not see it!! So everything, I thought was sorted out. I took a supply as suggested from the fuse/control box around to the fan supply, with a switch along the way. Took a return from the fan back to an earth (positive!!) back in fuse/control box. Whilst doing all this and testing as I went I never actually sat in the car, so could not see the ignition light. I just reached around and in, to operate the switch. However having finally got everything tidy wiring wise etc, I sat in the driver's seat, operated the switch and the ignition light come on not full on, but definitely glowing! I was using "spare" spade connectors in the box, but they do have connected empty spades which I used as appropriate. So, I have gone from being quite chuffed, to a little down hearted! (I am sure you know how it feels!!? (Incidentally when sorting things out, and checking the fan was running or not along the way, the fan ran when required, but not as fast as when it is fed direct from the battery. Might be worth mentioning?) I have a feeling it should be quite easy to sort out, but don't want to just keep trying things, so some firm guidance would be appreciated, if and when you have the time! Many thanks in advance folks, Have a great Easter and go easy on the chocolate! John Quote Link to post Share on other sites
RobH Posted April 11, 2020 Report Share Posted April 11, 2020 (edited) I'm a little confused about the location of the earth you are using in the "fuse/control box" - where exactly is that John? As standard the fuse box has no earth associated with it and although the dynamo control box does have an earth connection it probably isn't suitable to pass fan motor current through it so may be the source of the current flowing via the ignition bulb. it would be bestl to take the fan earth directly to a good solid point on the body, such as under a mounting bolt close to the battery. If you are taking a separately-fused power feed from the existing fuse box then the best point would be one where the two brown wires connect (A1). Normally that just feeds the horns so isn't doing much most of the time. (The supply to the other fuse - white wires- comes via the ignition switch so it isn't a good idea to use that one as the extra load will burn the ignition switch contacts.) Edited April 11, 2020 by RobH Quote Link to post Share on other sites
spillman Posted April 11, 2020 Author Report Share Posted April 11, 2020 Rob, many thanks. You have clarified where I was going wrong. I will do what you advise tomorrow, and am totally confident all will be well! I do feel rather inadequate, but a good learning experience! Cheers John Quote Link to post Share on other sites
spillman Posted April 12, 2020 Author Report Share Posted April 12, 2020 Morning All. Happy Easter. The fan is now running full tilt, controlled by the switch as per Rob’s final directions. Rob much appreciated. One feels a little stupid, having realised now how simple the job is/was. As mentioned previously it was a good learning experience, and I won’t forget in future that the car is positive earth. Thanks again everybody, and enjoy Easter. Stay safe John Quote Link to post Share on other sites
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