I forgot to say mine didn't like start on a cold winters morning. Lots of cranking, even with lots of heater plugs. Not like the 300TDi Ive got now, no glow plug touch the starter and it bursts into life.
Martin
1996 Defender 90
As Siggy says wire them into the yellow battery. This means you can flatten your yellow top & still start off your red top.
I would personally fit an isolator switch to the winch. I remember reading, in oz people used to drag the winch cable over the roof of the vehicle and attach it to the tow bar. They then shorted out the control box so the cable spoolled in and cut the vehicle in half.
Martin
1996 Defender 90
My TD when I had it, had done over 120k that's plus winching (mechanical) for the water board.
It still pulled like a horse when I sold it, and it was fitted with a disco transfer box.
The only thing I found with it, was the temp always read just under the red.
Martin
1996 Defender 90