i've been thinking about this for a while, and have considered getting the eberspacher TP4 remote control. But for a factory unit, i don't really like the look of it (like a little radio). Also i have limited space under the rear seat to store a box with phone and pcb in it, and knowing me i'll never remember to charge the bloomin phone!
The few things i'd like my eber to do is;
1, remote start
2, manual overide from the driver seat
3, thermostat (inside D1LCC) to still function with both the above
4, clock/timer fitted and working
What i plan to do;
at the moment i just have this rheostat fitted
this works well, has a positive off and works in conjunction with the thermistor in the heater. But you have to physically turn it on and set the right temperature each time you want it on.
So, im going to get a mini timer like this
This will work in conjunction with the rheostat, meaning the rheostat can be left set at a certain temp as it will only 'work' when the timer is in a on period.
Next i will fit a 3 way switch up by the steering wheel, maybe like this
Then run 3 wires up to the switch from the timer at the back. Then splice in to the thin red wire in the loom that goes to the timer and connect it to the middle position on the switch. Cut the yellow (which is the power on wire) connect one end (timer) of the yellow wire to one of the outer connectors on the 3 way switch, and the other cut end of yellow wire (to heater) to the 3rd connector on 3 way switch. This should mean with the switch in say position one, the heater will work with the timer and rheotat.
And if your about to go for a drive and the van interior is cold, flick the switch to position 2 and the heater will fire up.
If i then want to fit some sort of remote control to the heater, i would fit and connect it under the dash to position 2 on the 3 way switch, which will then liven up the heater. Having that side of the controls under the dash should make it quite easy to put in a nice red led on the dash to confirm the remote has turned it on.
Hopefully that will give me what i want, won't be able to try any of it until next year as my van is away getting beauty treatments and a heart transplant
Hope that makes sense, if it sounds like it won't work, do say..
Time is a drug. Too much of it kills you
. I always forget to make a call from the phone every now and then - resulting in a new SIM card due to inactivity. 
