Hi David,
The SatNav and cameras won’t draw much current so I don’t imagine any issues using the cig lighter socket for them. The seat heater might be another matter though. Check the fuse rating for the cig socket and use the formulas below to calculate if the fuse is up to running all your gear. Is there any reason you can’t use the existing wiring/ switch for the replacement? If it’s because you can’t/ don’t want to get inside the seat then you can always connect your new pad to the existing wiring under the seat. That way the existing switch should still be ok. What you’ll have to check is the power required by the new pad and the fuse rating for the old pad.
Here’s how:
Power (Watts)= Voltage(Volts) x Current(Amps)
What you need to know is current. The voltage is 12V, the power should be marked on the pad or in the instructions. Let’s say for ease of calculation it’s 60W(Watts). The formula is:
Current = Power divided by Voltage,
so,
C = 60/12 = 5 Amps. That’s the current the pad will draw so the fuse needs to be at least that, preferably 7.5A or 10A otherwise you could get nuisance blowing.
If you’ve no information on the power rating of the pad it’s not the end of the world but you’ll need a multimeter and a Google search on how to measure current. It’s easy once you know how and at 12V nobody’s going to get hurt.
Hope it all makes sense and helps.
Cheers,
Michael.
