Battery Cable Upgrades + Ford Starter Solenoid + Fusible Links = ARGH!!

[colokevin]

Recently I tried starting my '90 350 Suburban 1500 on a sub-zero morning. Cranked and cranked, but never started (worked fine the warm night before.) A few days later when it got warmer, it would still crank, but never start. In fact, I eventually had a "runaway" starter, so I pulled the battery cable to stop it. So now I have NO electrical anywhere (with battery reconnected obviously). No starter, no fuel pump, no lights, NADA. Fine, I probably blew a fusible link somewhere, so I decided to upgrade the entire battery cable system and do the Ford starter solenoid upgrade too. So I ripped out all the wiring between the battery, alternator, starter and junction block. (Interestingly, all 3 of the wires with stock fusible link have good continuity when I test them.) I'm a big fan of overkill, so I bought 4/0 welding wire to replace all of the battery cables, as well as several different size fusible links. I was intending to connect the fusible link end of the new cables to the battery (for easy access) and the other end to the 4/0 wire, then off to the solenoid, starter, etc. ***So how do I connect 4/0 wire to 12/14/16AWG fusible link? Just solder them together? Does it even make sense to do it that way?*** My thought was that my electrical load hasn't changed from stock, therefore I can use the same size fusible link as OEM. My goal with the overkill battery cables is to decrease wire resistance significantly to ensure I get full battery voltage to everything downstream in the truck. But will a relatively small fusible link cause a bottleneck with 4/0 cable, or is it insignificant because of its minimal length? I have a feeling I'm coming at this all wrong……? What is the "right" way to upgrade my battery cables, but still have protection?

 

[YOUNGBLOOD13]

Holy crap, no. The fusible link is for protection of the wiring it is connected to. Your starter and battery are not fused, too high amperage.
The fusible links go to main power feed and any other high current circuits you have. Check out MadElectrical, on Google I guess, Mark has some real solid tech info and sells all kinds of upgrades

 

[Blazooki]

think of the fusible link as a gate that all the electricity runs thru to get to into the truck from the battery/alternator. The starter, battery and alternator are a totally separate system loop and don't need, use or want the fusible link. They run in thier own little circle. All the fusible link is a type of fuse. You can change it to a regular pin type fuse or a circuit breaker if you want to (which is what I have) and is way easier to disconnect/reset/ know if its been tripped. Since you yanked it all, I'd do a 150 amp circuit breaker instead of the fusible link. check out a local car stereo store or amazon.

Since the truck was cranking over originally then you didn't have a power problem so its either spark and/or fuel related.

 

[ryoken]

what that guy said...


4 aught is way overkill for bat cable.. I run 2/0 marine and it's stooopid fat... 10 g to the junction block is fine from the starter and alt.....

 

[colokevin]

I'm following what you guys are saying, but I still don't understand how I should integrate the fusible links in my system. In the stock system, there are fusible links between: 1)junction block to starter, 2)junction block to firewall connection, and 3)firewall connection to alternator. Whether I use fusible links, fuses, or circuit breakers, I still want to protect those 3 locations, same as stock, right? Since I'm adding the Ford starter solenoid, here's how I was intending to run my wiring: 1)alternator to battery, 2)battery to ford solenoid, 3)solenoid to starter (1 wire feed plus the jumper), 4)solenoid to junction block, and 5)junction block to firewall connector. Which of these should I use a fusible link/fuse/CB? Also, why does the stock system not use a fusible link between the alternator and battery? --Thanks for the help; I'm obvious a newb on electrical systems.

 

[colokevin]

Here's how I plan on running my wiring and fusible links; hopefully someone can tell me if this seems OK or is unsafe:

1)Large gauge wire from POS battery to new Ford starter solenoid (no fusible link)
2)Large gauge wire from Ford solenoid to factory firewall junction block (no fusible link)
3)Stock wire from junction block to firewall connector (with stock fusible link)
4)Large gauge wire from Ford solenoid down to starter (with fusible link) with jumper from main starter terminal to start terminal
5)New wire from alternator to battery (no fusible link)
6)Stock wire from firewall connector to alternator (with stock fusible link)

YES/NO?
Am I correct that the 3 factory fusible links protect the wiring in case: 1)alternator fails, 2)starter fails, or 3)some ground fault on the way to the in-cab circuits??

 

[ryoken]

you don't need, or want, one on the main feed from the slave solenoid to the starter... cranking amp load will nuke that in short order....

 

[ryoken]

here's that main stuff on my K5 setup...... 1 cab breaker, that's it.... the 1,2 c circle is a marine switch..

 

[colokevin]

here's that main stuff on my K5 setup...... 1 cab breaker, that's it.... the 1,2 c circle is a marine switch..

Gotcha, so you go from batteries to marine switch to slave solenoid to starter without any CB or fusible link, then use a CB to protect the cab circuits. I want the CB as downstream as possible, between the firewall junction block and the firewall connector, right? What size CB to protect the cab circuits?

Any pro/con to running the alternator charging wire to the slave solenoid vs direct to the battery? Same/same?

 

[ryoken]

Gotcha, so you go from batteries to marine switch to slave solenoid to starter without any CB or fusible link, then use a CB to protect the cab circuits. I want the CB as downstream as possible, between the firewall junction block and the firewall connector, right? What size CB to protect the cab circuits?

Any pro/con to running the alternator charging wire to the slave solenoid vs direct to the battery? Same/same?

I like to keep 1 connection at the bats.. multiples add to corrosion issues... so yes, putting the alt wire to the bat post of the solenoid is preferable.. you'll notice mine is set up that way..

as far as a cb for cab protection, to be honest, it's been soooo long since I did mine, I forget what I spec'd it at..... you need to look at what your cab loads could be... I would say run it right before the jc by the brakes or right after....

keep in mind, circuits have start up amp draws, and constant amp draws... adding accessories like lights, etc all add to that #... iirc, I ran an 80 amp and never had an issue... like this one... your mileage may vary... a 60 would probably do you fine and will protect the 10 gauge better...

https://www.walmart.com/ip/Bussmann...0364&wl11=online&wl12=152501754&wl13=&veh=sem




just grabbed that link thru google... it always amazes me the stuff that you can order thru Wally World...

 

[ryoken]

I should postface that reply too... if I was gonna feed the stock bulkhead, I would run a 50 or 60 amp breaker up at the JC... you ARE limited by the 10 gauge feed to the bulkhead that you need to protect... now that I'm looking back at my setup a bit, my cab electrical eliminates the stock bulkhead and goes to the custom interior breaker setup, so the feed was upgraded to 6 gauge, thus I can run an 80 amp breaker... technically, 10 gauge can only handle 55 amps, so a 50 amp breaker would be ideal....

 

[nutt7]

I should postface that reply too... if I was gonna feed the stock bulkhead, I would run a 50 or 60 amp breaker up at the JC... you ARE limited by the 10 gauge feed to the bulkhead that you need to protect... now that I'm looking back at my setup a bit, my cab electrical eliminates the stock bulkhead and goes to the custom interior breaker setup, so the feed was upgraded to 6 gauge, thus I can run an 80 amp breaker... technically, 10 gauge can only handle 55 amps, so a 50 amp breaker would be ideal....

This. Always make sure your protection will blow before the wire. The main goal is to protect the wire. In terms of fusible links, the standard is four numbers smaller wire. If your wire is 10awg, your link should be 14awg. Main alt wire should go to the battery. If it has a smaller "sense" wire, put it where the biggest distribution point is. Remember to protect the wire! Any distributed wires should have its own protection.

 

[nutt7]