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| | | | Joined: Sep 2009 Posts: 433 'Bolter | | 'Bolter Joined: Sep 2009 Posts: 433 | What would be the fuse size for the heater on a 54 3100 6 Volt motor ?
Thanks again...
1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years
Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974
| | | | | Joined: Jun 2008 Posts: 1,388 Shop Shark | | Shop Shark Joined: Jun 2008 Posts: 1,388 | I use a 20amp, same as my other fuses. Maybe one day I'll burn up though? | | | | | Joined: Sep 2009 Posts: 433 'Bolter | | 'Bolter Joined: Sep 2009 Posts: 433 | Thanks Mr. Lang... I am having to rewire from the motor to the power source because the original wire was gone... I do not remember seeing a amp # on the motor when I cleaned it up... The 1929 - 1957 Chevrolet Master Parts & Accessories Catalog does not say anything about what specific size ( Amp. ) it used for the motor... All though the do have a list of fuses with part #'s, amps and lengths of the fuses but no mention as to where they go...
1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years
Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974
| | | | | Joined: May 2007 Posts: 289 Shop Shark | | Shop Shark Joined: May 2007 Posts: 289 | I am not sure about a '54 but all the earlier models had the fuse on the back side of the switch that was mounted on the underside of the dash. | | | | | Joined: Jan 2010 Posts: 4,263 Shop Shark | | Shop Shark Joined: Jan 2010 Posts: 4,263 | The fuse on the back of an NOS under dash switch I purchased is 14a ...pic... Someone may have placed an incorrect fuse in the holder, but that's what's there Good luck | | | | | Joined: Sep 2009 Posts: 433 'Bolter | | 'Bolter Joined: Sep 2009 Posts: 433 | Thanks again Gus...
I wired the fuse from the power source ( ignition switch ) to the new heater switch... I did it this way because the old heater switch showed signs of overheating ( melted looking )... That is why I needed to know the correct size fuse...
1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years
Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974
| | | | | Joined: Feb 2004 Posts: 29,771 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,771 | Fuses are rated to protect the size of wire that's being used. If the 14 amp fuse is correct, that's intended for approximately a #12 wire. You would need to measure the current draw of the motor in question, and add about a 50% overload capacity to the fuse, then use the right size wire to carry the current draw. The whole concept of a fuse is to interrupt the circuit before the wire can overheat to the point of damage. For instance, a 20 amp fuse on a #18 wire would allow a current flow sufficient to melt the insulation before the fuse would fail. A #18 wire works best with about a 7.5 amp fuse, maybe 10 amps max. As the accessory load and the wire size increases, the fuse size goes up to match it.
Edit: Dirty switch contacts or loose connections can result in localized overheating and damage, even if the wire and fuse size is correct.
Jerry
Last edited by Hotrod Lincoln; 11/23/2011 5:53 PM.
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| | | | | Joined: Sep 2009 Posts: 433 'Bolter | | 'Bolter Joined: Sep 2009 Posts: 433 | Thanks Jerry,
You are right about the dirt, it did see its fair share of very dusty roads...
1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years
Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974
| | | | | Joined: Aug 2009 Posts: 295 Shop Shark | | Shop Shark Joined: Aug 2009 Posts: 295 | Jerry said
"You would need to measure the current draw of the motor in question, and add about a 50% overload capacity to the fuse, then use the right size wire to carry the current draw".
Jerry is 100% correct - so correct this should be posted as a standard reply. On a small motor ie truck heater motor I go along with the 150% to allow for startng current since in many truck cases teh fuse has a multiple role ie fault current, motor starting current and motor overload protection.
Dan Bentler
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