The Ford Barn

Cody_1948 · 08-20-2023, 06:28 PM

Hi Guys, I have a aftermarket headlight switch (older style) in my truck which is still 6v I have newer wiring kit I updated the truck with. I'm having hard time trying to find what amp fuse to use with the switch with the 6v system. The headlight switch is the only glass fuse I see in the whole truck. Been told glass fuses where never used in these trucks.

Any help would be great.

Thxs a million

Best Regards

Cody
Michigan

Sent from my Celero5G using Tapatalk

Bob C · 08-20-2023, 07:24 PM

They had circuit breakers.

koates · 08-21-2023, 04:37 AM

The fuse on your aftermarket switch would only power all of your lights so as long as all your lights are all factory original specs then a 20 amp fuse would be OK. If any bulbs are higher wattage than factory specs then the total current draw (amps) through the switch would have to be measured. Regards, Kevin.

BlueSpark · 08-21-2023, 04:34 PM

Yeah like Bob said you want a breaker. These were thermal, slow-blow types so a quick transient overload will not blow it and if it still does it will automatically reset when it cools off. This doesnt mean you will get the lights back necessarily but at least you have a chance before running off the road. They are still available I believe.

Bob C · 08-21-2023, 05:36 PM

You should have two breakers behind the instruments.

petehoovie · 08-21-2023, 05:47 PM

Sponsored Links (Register now to hide all advertisements)

Quote:

Originally Posted by Bob C

You should have two breakers behind the instruments.

52flthed · 08-21-2023, 07:58 PM

when we did my complete rewire we added a few in-line glass- period correct type buse fuses to certain accessories that really needed it. Like an engine compartment light for instance was one example. If that goes it'll catch fire. Ask me how i know. I would add that to certain accessories like a cigar lighter, heater, or additional lighting if you have any of that stuff. It could really save you.

koates · 08-21-2023, 08:07 PM

Yes, Yes we all know it should have circuit breakers as originally fitted but it has a new non original wiring kit fitted and all he wanted to know was the value of the fuse on the replacement headlight switch. Many cars had fuses and not circuit breakers. Circuit breakers are safer because if there is a short in the lighting circuit then the breaker contacts will open for a short period and then close again quickly when cooled and possibly give you lights again. Regards, Kevin.

rotorwrench · 08-21-2023, 08:29 PM

The wire gauge is what designates sizing of circuit protection. Breakers and fuses protect the conductor wire. 6-volt systems require larger gauge wire then 12-volt systems. You can use a lower rated fuse to protect a wired circuit but you can't use a higher rating than the wire requires or the wire could burn before the fuse.

I use the FAA advisory circular AC 43.13-1B chapter 11 to find fuse and circuit breaker ratings for the different American Wire Gauge sizes.

08-20-2023, 06:28 PM	#1
Cody_1948 Senior Member Join Date: Sep 2011 Location: MI Posts: 211	48-50 F1 headlight switch glass fuse help 6v Hi Guys, I have a aftermarket headlight switch (older style) in my truck which is still 6v I have newer wiring kit I updated the truck with. I'm having hard time trying to find what amp fuse to use with the switch with the 6v system. The headlight switch is the only glass fuse I see in the whole truck. Been told glass fuses where never used in these trucks. Any help would be great. Thxs a million Best Regards Cody Michigan Sent from my Celero5G using Tapatalk

08-20-2023, 07:24 PM	#2
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,754	Re: 48-50 F1 headlight switch glass fuse help 6v They had circuit breakers.

08-21-2023, 04:37 AM	#3
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: 48-50 F1 headlight switch glass fuse help 6v The fuse on your aftermarket switch would only power all of your lights so as long as all your lights are all factory original specs then a 20 amp fuse would be OK. If any bulbs are higher wattage than factory specs then the total current draw (amps) through the switch would have to be measured. Regards, Kevin.

08-21-2023, 04:34 PM	#4
BlueSpark Member Join Date: Feb 2023 Location: San Jose CA Posts: 61	Re: 48-50 F1 headlight switch glass fuse help 6v Yeah like Bob said you want a breaker. These were thermal, slow-blow types so a quick transient overload will not blow it and if it still does it will automatically reset when it cools off. This doesnt mean you will get the lights back necessarily but at least you have a chance before running off the road. They are still available I believe.

08-21-2023, 07:58 PM	#7
52flthed Senior Member Join Date: Oct 2019 Posts: 175	Re: 48-50 F1 headlight switch glass fuse help 6v when we did my complete rewire we added a few in-line glass- period correct type buse fuses to certain accessories that really needed it. Like an engine compartment light for instance was one example. If that goes it'll catch fire. Ask me how i know. I would add that to certain accessories like a cigar lighter, heater, or additional lighting if you have any of that stuff. It could really save you.

08-21-2023, 08:07 PM	#8
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: 48-50 F1 headlight switch glass fuse help 6v Yes, Yes we all know it should have circuit breakers as originally fitted but it has a new non original wiring kit fitted and all he wanted to know was the value of the fuse on the replacement headlight switch. Many cars had fuses and not circuit breakers. Circuit breakers are safer because if there is a short in the lighting circuit then the breaker contacts will open for a short period and then close again quickly when cooled and possibly give you lights again. Regards, Kevin.

08-21-2023, 08:29 PM	#9
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: 48-50 F1 headlight switch glass fuse help 6v The wire gauge is what designates sizing of circuit protection. Breakers and fuses protect the conductor wire. 6-volt systems require larger gauge wire then 12-volt systems. You can use a lower rated fuse to protect a wired circuit but you can't use a higher rating than the wire requires or the wire could burn before the fuse. I use the FAA advisory circular AC 43.13-1B chapter 11 to find fuse and circuit breaker ratings for the different American Wire Gauge sizes.