Martin R Posted June 7, 2008 Share Posted June 7, 2008 Ive been tinkering again Ive thought for sometime it would be good to have a manual fan switch. Mostly for use on trackdays but im sure it will come in useful if we ever have a summer and im stuck in traffic. Ive had a nosey and this is how it works ( i think ) The fan is switched on via a relay due to the load currents. This is controlled by the MEMS ECU. The positive side of the relay coil is always live when the ignition is switched on. The ECU grounds the other side of the coil when the fan is required. After a question on SELOC as i could not find a car wiring colour code for the Lotus, it turns out the wire is Blue and slate Grey. A pic of the underneath of the relay box with the wire. The wire i wanted is the second one from the left on the top. Ive bought a switch and took the dashboard apart as well. It turns out the dummy switch ( the one to the right of the headlight switches etc ) has some connections on the back. Ive no idea what these are for. Another pic. I traced the Blue / Grey wire to see where it went to see if i could make the job easier. It turns out it runs in the centre console of the car. Obviously on the way to the ECU. I stripped off the tape on the loom with a craft knife. Another pic Im not wildly keen on cutting wires in cars. Ive therefore stripped the wire ready to solder another wire to it. Another pic. Next i tinned the stripped wire with solder. Attached the wire to go to the switch. Also retapped the section of the loom i had stripped, you can see the new wire coming out for the switch. I cable tied this along the existing wires till we got under the dash. The fun part was being upside down in the footwell trying to thread the new wire to the existing switches. One i had done this, i used the black off the dummy connector to one side of the switch and the new wire to the other side. A couple of connectors later. A small stick on label and we are done. Suprisingly it works. The switch missing in the final picture is my fog light switch. This is deceased i found whilst doing the job. Im going to order a new one. I may try and get the lights in the switch working at a later date but ive got to get the rest finished before Donington on Tuesday. It will have to keep for now. Link to comment Share on other sites More sharing options...
Steve J Posted June 7, 2008 Share Posted June 7, 2008 I think the wires/switch was left over from a rear screen heater in the Pugs? Link to comment Share on other sites More sharing options...
Martin R Posted June 7, 2008 Author Share Posted June 7, 2008 I think the wires/switch was left over from a rear screen heater in the Pugs? Ah, ive really no idea Steve but i would not be suprised. The black on the back of the connector should do for a ground wire though hopefully. Link to comment Share on other sites More sharing options...
MilesH Posted June 7, 2008 Share Posted June 7, 2008 Nice one Martin, I look forward to the next installement - and if I fail in my attempt to copy you I've not far to go to get your help! Link to comment Share on other sites More sharing options...
Martin R Posted June 8, 2008 Author Share Posted June 8, 2008 Nice one Martin, I look forward to the next installement - and if I fail in my attempt to copy you I've not far to go to get your help! Miles im not sure the Honda ECU works the same way. I would be suprised if it didnt though. If you flip the relay box upside down and check if you have 12v on the second wire from the left on the bottom with the ignition on. If you have it would suggest it does work the same. Link to comment Share on other sites More sharing options...
MilesH Posted June 8, 2008 Share Posted June 8, 2008 Nice one Martin, I look forward to the next installement - and if I fail in my attempt to copy you I've not far to go to get your help! Miles im not sure the Honda ECU works the same way. I would be suprised if it didnt though. If you flip the relay box upside down and check if you have 12v on the second wire from the left on the bottom with the ignition on. If you have it would suggest it does work the same. Will do.......(runs outside to check before the light fades!) Link to comment Share on other sites More sharing options...
Martin R Posted June 8, 2008 Author Share Posted June 8, 2008 Ive just updated the first post with the rest of the job. Except for putting the dash back together etc Link to comment Share on other sites More sharing options...
Mish Posted June 9, 2008 Share Posted June 9, 2008 I got new buttons off a Pug 106 last summer, Circa 50p each if I remember correctly ... A question from an idiot here ! ... you tapped the blue & grey wire off the loom in the centre console, what is the other cable you have coming out of the back of the button ? If I wanted to do this what exactly would I need to do the job ? Hamish Link to comment Share on other sites More sharing options...
Martin R Posted June 9, 2008 Author Share Posted June 9, 2008 The other wire is connected to the Black ( ground ) wire on the connector that was on the back of the dummy switch. To do the job you need a suitable switch a length of wire and a few connectors. Also a soldering iron and a bit of solder and black tape HTH Link to comment Share on other sites More sharing options...
insanity Posted June 9, 2008 Share Posted June 9, 2008 Brilliant How To... and ideal for the Wiki - fancy adding it? (If not, I could mark the thread and do it when I have some spare time!) baz Link to comment Share on other sites More sharing options...
Phil.S Posted June 9, 2008 Share Posted June 9, 2008 Good write up Martin. This a job I also have on the cards Link to comment Share on other sites More sharing options...
Martin R Posted June 9, 2008 Author Share Posted June 9, 2008 Brilliant How To... and ideal for the Wiki - fancy adding it? (If not, I could mark the thread and do it when I have some spare time!) baz Please do, im better with a socket or spanner than a computer. Link to comment Share on other sites More sharing options...
insanity Posted June 9, 2008 Share Posted June 9, 2008 Please do, im better with a socket or spanner than a computer. The exact opposite of me... ha ha!! Anyway, I was bored, so it's up: http://www.midlandslotus.co.uk/wiki/index....nual_Fan_Switch I tried to keep it the same. All pictures have been uploaded to the wiki, this is so it doesn't rely on your photobucket account - hope this is ok! baz Link to comment Share on other sites More sharing options...
Martin R Posted June 9, 2008 Author Share Posted June 9, 2008 Excellent thanks for that. Get your Wiki skills ready for the winter. I feel a few jobs coming on Link to comment Share on other sites More sharing options...
Mish Posted June 10, 2008 Share Posted June 10, 2008 Cool ! I now have a full weekend of 'CAR' can't wait !! h Link to comment Share on other sites More sharing options...
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