Parking heater with Webasto remote in the Lotus Elise ECE

Before I owned the Lotue Elise ECE, I drove a Landrover Defender, it was fitted with a parking heater which is very nice in winter. Especially when it’s freezing and you want to pre heat your car interior. Pre heating your EV while it’s loading won’t affect your EV’s range. My EV has no parking heater, so I wondered if I could use the already installed MES-DEA RM4 as parking heater. Due my experience with the Webasto parking heaters I knew that de remote option, which is sold separately, could be used as standalone remote. I used the Webasto Telestart HTM100 because it is able to display the actual temperature in the car on the remote.
In my EV the MES-DEA heater is controlled by an on/off switch on the dash. It’s only working when the ignition is switched on. since I don´t want to leave the key in the ignition over night, in needed an other solution. I connected the control wire from the MES-DEA directly to +12 volt to see if the heater would fire up, it did. I installed a relay which is controlled by the Webasto remote, when it’s active it disables the original switch and connects the control wire from the MES-DEA to +12 volt.  To get the heat in to the car the interior fan needs to be switched on, I used a relay to connect the interior fan directly to +12 volt.

25-10-2015 Update: see part II