maxi fuses (info needed)

[moparmat2000]

There has been some discussion on another thread about using maxi fuses to replace the fusible links in our cars such as the fusible link for the charging circuit, alternator direct to battery. As well as for the body harness.

I have looked all over the net and cannot seem to find a fusible link to fuse direct cross reference. My alternator is a 50A max output. It will be an 8 gage lead wire approx 8 foot run with a 12 gage fusible link. The body wiring is protected with a factory 16 gage link.

Obviously you want the link or fuse to pop before the wiring cooks. Is there a chart, or formula (chart preferred) to figure out what maxi fuses would be needed to replace the 12, and 16 gage fusible link wires so that these pop before i end up with a carbeque in case of a dead short to ground.

Thanks
Matt

 

[67Dart273]

Sure, size it to protect the 8ga wire, or if in doubt upsize the wire to no6. If the alternator is truly around 50A then I would think a 50A fuse "would do it." I've never really found a chart / reference to what the old fuse links "were" and worse, a comparison to third party fuse links vs OEM

 

[moparmat2000]

Thank you. I am mocking up all my electrical, and mechanical stuff i might have issues with before i pull it back apart to finish the body and paint. I want everything layed out and modified to
suit now so i can just assemble it when the time comes.

I talked about fusible links but the maxifuses seem like a better idea. Since it is all being mocked up, im not sure about the max amp draw on the body end. There is one 16 gage fusible link at the firewall in the batt hot circuit that goes to the amp gage and alternator. It protects the stock 12 gage wiring.

I dont intend to add anything to this car other than maybe an electric engine fan, on a relay, and headlamp relays. Its a radio delete car, i may just keep it this way. With the headlamps using relays that drops the amperage in the lighting circuit.

Any idea on a maxi fuse to replace a 16 gage fusible link??

Thanks
Matt

 

[txstang84]

Hey Matt, this might be of some assistance...

http://www.engineeringtoolbox.com/wire-gauges-d_419.html

 

[emsvitil]

Try this:

http://www.powerstream.com/wire-fusing-currents.htm

 

[blown71duster]

Here is a source for fuses replacing fusible links.

http://minimopar.net/electrical-links.html

I would say a 40 amp fuse and add relays anywhere you can .

 

[Pete in NH]

I would use a 50 amp Maxi-Fuse on the 50 amp alternator circuit. That one is easy, you want to fuse at the maximum current you expect in the circuit. Basing current protection on wire size is a bit misleading in this case. You are using #8 wire to minimize voltage drop and losses but, the maximum expected current in the circuit is still the 50 amp alternator output.

I would replace the body wiring fusible link with another 50 amp Maxi-Fuse. 50 amps is around the capacity of the 16 gauge fusible link. I say around because there are several variables that determine when a given link will melt. Because of these variables I don't think you can actually come up with an accurate chart of fusible link melting points and I too have never seen one. You can however, find information on the maxi-Fuses in terms of percentage of over load and melting time.

The nice thing about Maxi-Fuses is they are readily available if you need one. I've even seen them in large hardware stores.

 

[blown71duster]

Here is another source of information about wiring amperage capacity taken from an article that Ron Francis wiring did.