Wowed, how to figure out fuse to use.

That calculator will not work for you unless you know the "power" of whatever is hooked up. If you knew the current already you'd have your fuse size. kgerry hit the nail on the head with the relays.

With anything you are unsure of just start with a small fuse. Too small a fuse will not hurt anything, it will just blow if too much current is on the circuit (or a short). You can also put a DMM in series with any wires you have doubts with and check the draw. Start at the highest setting on your meter  (set to measure current of course) and work down. Some meters will have a seperate plug for higher current applications, if so use that first. However, if the wire you are testing is connected to something that is not operating or "on", you won't get the current reading you want.

Good Luck

Your welcome, and it is VERY wise of you to be concerned about the lack of fusing.

Imagine if you work on this "burnt toast" car and the next day something you had nothing to do with decides to lay against the exhaust manifold or gets pinched somewhere. Now I don't know about your customers but mine would surely blame me, which is why I will turn down ANY job that has unsafe wiring unless I am paid to fix the probelms first.

I live in a land of DIY'ers and almost twice a week see the infamous 4 gauge ran through the fender/doorjamb area, swinging next to the exhaust manifold, unfused of course. Then I get the old "it's fused in the back..isin't that ok??"

I say "sure it's ok, if you don't mind one day standing next to your vehicle on the side of the road while it's smoking and burning", then you will be saying "would you look at that, wow, I wonder why that happened? ".