Best place to install fuse

Peter J

Peter J

Well-known member
Today I purchased a "heavy duty" inline fuse holder with #12 wires. I also bought a pack of 30 amp. fuses. Where would be the best place to wire it in?

Thanks Guys,
Pete
 
If you have but one fuse to give, you want it as close to the hot post of the battery as possible. The setup that mounts on top of the starter motor switch makes a lot of sense. So, I would insert the inline fuse between the starter switch and the junction box. Since some of your wiring is probably not rated for 30 amps, be sure and don't use a slow-blow fuse--you want to minimize the chances that the insulation on a shorted skinny wire will be hot enough long enough to catch on fire.

Steve
 
I did what you are going to do. I resoldered the holder with the original harness wire to look better and I use a 20 amp fuse
 
I cut the yellow wire and soldered the holder "buttons" to the yellow wire. Looks better that way
 

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The reason I would not use a 20 amp fuse is that quite often after the car has been sitting for a week and I start it up the battery charging current draw pegs the ammeter at 20 amps. I am running a six-volt positive ground alternator. This current is flowing through the fuse. If it should blow before the battery reduces the draw back to zero the alternator would be disconnected from the battery and it could run wild doing damage to the ignition coil and any lights turned on. I run a 30 amp fuse.

Tom Endy
 
Tom Endy said:
If it should blow before the battery reduces the draw back to zero the alternator would be disconnected from the battery and it could run wild doing damage to the ignition coil and any lights turned on. I run a 30 amp fuse.
Click to expand...

If the Alt runs wild you have a defective Alt.
 
Just installed this one on mine, kind'a vintage looking and bolts on the motor side of the starter switch screws.

A11450SF-7248-xl.jpg
 
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Great! I sort of thought the pole on the starter would be the best place to wire from. That's what I want, if theirs trouble, I want the whole system shut down.
Thanks for the pics. as well. Lots of help.
Pete
 
I believe there was a discussion on the old Fordbarn about these types of fuse holders having problems. I think it was something along the lines of them shorting out and over heating. I think a better choice would be to mount a plastic holder on the inside of the firewall away from all the dirt and most of the vibration. You would not see it unless you looked up under the gas tank if it was mounted next to the terminal box.
 
Peter J said:
Great! I sort of thought the pole on the starter would be the best place to wire from. That's what I want, if theirs trouble, I want the whole system shut down.
Thanks for the pics. as well. Lots of help.
Pete
Click to expand...
The fuse as described on the starter is a must-have! But keep in mind that there is one part of the electrical system it does NOT protect: the starter switch and starter. If you have a malfunction in either of those items, you have a real problem. That's where the electrical system cut-off switch comes into play, and which should be installed in the ground wire for complete battery isolation.
 
When I first put my car on the road(1972)I had the fuse that is mounted on the starter switch, that day the holder failed, caused the generator to overvoltage and fail, I took it off, kept Henery's design.

A fuse at the starter will not totally protect the wiring while the engine is running ,the light wires are connected to the charging system, a short in the lights could blow the fuse, the generator (or alt) can still feed the light circuit ---perhaps the fuse should go in the lighting system feed, with a seperate fuse for anything you run off the terminal box (domelight?)

Sometimes I think that the modifications done to improve the car cause more problems than what they are designed to fix.
 
Kurt,
I agree in the KISS approach. I'll probably just go with the line to the starter and a good cut-off switch on the ground side of the battery. Regarding improvement mods. I also remember that ole Henry was also in the parts business to repair his cars when they broke down. To paraphrase him: "Let someone else build the cars, I'll sell the parts to repair them."
Pete
 
Just my OP! I would not put that fuse holder shown above in my car. If the base insulation was thicker and mounted independent of the wire terminals yes maybe. As it is, the terminal screws are going through the whole thing holding it together. It looks to be cheep insurance on your $15,000 car!
 
redmodelt: I disagree with you, I just replaced the other style offered by some vendors (rivited with a large bolt soldered on one end) after having it fail on me twice. In my opinion this is a better style. JMO
Paul in CT
 
Me bad, you are right. I over looked the rivets.
I still would not mount one on the starter. Where ever you mount I would want it protected from oil, dirt, water, etc. I have mounted two on the firewall inside next to the terminal box. The yellow wire should be long enought to take it off the terminal in the box and feed through for hook up. Then a short jumper goes back to the power terminal.
Just because these are the only ones carried by the parts suppliers does not mean you cant make your own, they are not that hard to make.
 
Jazzjr: BEWARE!! Those large nuts/bolt just soldered to fuse holder end, if not careful while tightening down it comes apart and VERY difficult to resolder without damaging fuseblock. Mine broke, resoldered, joint failed 5mi from home. Got the other style shown in an above post from Snyder's, it's the better of the two. JMO
Paul in CT
 
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