The Stovebolt Site Forums The Shop Area The Electrical Bay what amp fuses needed?

hi all, I have a '53 3100. it is now 12v with all standard bulbs, no LED lights. left and right tail lights, dual filament park lights. I have a signal stat 900 switch in it. I am putting an in-line fuse before the switch and I can't find info on what amp fuse to use, so what size fuse should I protect the blinker system with? also, being that it is now 12v, should I replace the 20 amp fuses for the tail and stop lights with 10 amp fuses? thanks in advance (design)!

I'm sure someone else will jump in here but I would think 20A would be fine all the way around providing your turn signal wiring is the same gage, or close to the same gage, as the rest of your fused wiring.

The fuse's job is to protect the wiring in the event of a short. A short is infinite amps so your wiring and fuses don't care what the voltage is.... only the amps. If your wiring was designed for 20A in a 6V system it will do 20A in a 12V system as well.

Best regards,
Les

Les is right. Use a 20amp on the turn signals & leave the others as is.

I read in the tech article, from cletis, about installing blinker kits. He mentions adding a 5 amp fuse to the more simple signal stat 700. He says to fuse the 900 as well but didn't mention an amperage. Perhaps a 5 amp as well?

As long as the fuse is sized to protect the smallest gauge wire used in the entire circuit you will be fine. How small are the wires on the turn signal unit?

18 Gauge wire = 5 amp

16 Gauge wire = 10 amp

14 Gauge wire = 15 amp

12 Gauge wire = 20 anp

10 gauge wire = 30 amp

Hope this helps,

Mike B

The wires don't have any identification on them, but they look like either 14 or 16g. Your wire size/amp chart is helpful, and fusing according to wire size is very logical.

Thanks, Mike B

That's exactly the information I was looking for next week

Lemmm117,

Use your wire strippers to confirm the wire gauge...

Mike B

It appears that the wires are 16g. One interesting thing to note is when installing this switch, the directions say CAUTION: power lead must be connected to a line which is hot when ignition is off for hazard warning signal to operate when motor is not running! I'd assume that often times people would hook it up to a power source that is only hot when the ignition is on, and that wouldn't work out too well if your broke down on the side of the road.

The flip side to that is that can accidently leave the truck parked with the blinkers going.

ALSO, you might want to wire in a relay for the headlights if one is not already installed.