Fuse issue

[Ramcharger90]

So I relocated the battery from the engine bay to a tool box on the bed. I ran three 2 awg wires one went to the frame, one went to the starter solenoid , one went from the top post of the alternator to the positive terminal on the battery. This one has a 60 amp fuse in between the alternator and the battery. This fuse popped today so I put another one in and it started to charge, then the gauge started to drop so I went to look and see if it popped again, it didn't so I ran the rpms up and this fuse exploded into a fire ball. It has never done this before I'm not sure where to start looking for an issue. I drove the truck literally 10 miles today before this happened. I have had a slow crank or crank stoppage issue for a lil bit but I figure I needed a high torque starter or 1/0 awg wires I already replaced the ground with a 1/0 awg wire but still the slow/no crank issue continues.

Already have
New battery
New starter solenoid
New starter
New alternator

 

[RonD]

Whats the amp rating for the alternator?

So the "wire" distance between battery and starter motor is?

And the engine is grounded to frame by a larger ground strap?
"....one went to the frame...."
Engine and trans sit on rubber mounts so they are NOT grounded to frame very well, so you have to have a larger ground strap from engine to frame for your setup
And alternator uses engine as its ground, so...................

You can just run the alternators B+ wire to starter solenoid's Battery positive wire
The 3rd wire all the way back to the battery means more resistance because alternator voltage has to travel to the battery and then BACK to starter solenoid to power the vehicles systems

Battery is only 12v but alternator puts out 13volts so battery is not even used when engine is running
So alternator is working overtime to get voltage to travel in 20+ feet of wire regardless of the gauge

So get rid of that 3rd wire
Use a fuse and wire from alternator B+ to starter solenoid
And add a ground strap <<< this could be why cranking is slow

When you are starting the engine, voltage runs from battery positive to starter motor, then OUT of starter motor back to battery negative, a "circuit"
Most starters need 60-70amps, and BOTH + and - must pass that 70amps out and back in to the battery
If either + or - can only pass say 40amps, then 40amps is all that can flow, so slow cranking

 

[Ramcharger90]

I have 3 separate grounds going from engine to frame.

The fuse issue has just started.

I was driving the truck for months this way, this started after I drove the mustang for 2 straight weeks and the ranger just sat in my garage. But if I dont need a wire going from the alternator to the battery then I will get rid of it. That alternator is newer. like last fall new... but that 60 amp fuse has been on the truck well over a year. The only thing that has changed in terms of wiring is the length of wires. And the addition of a kill switch near the battery.

The slow starting has been getting worse over time especially after the engine is warm.

Its more than likely a 130 amp alternator. I forget why we used that 60 amp fuse. There was a reason. I cant remember why though.

 

[RonD]

Pretty much all alternator amps are consumed by the vehicle electrics, the amps that go to battery to charge it are minimal

So yes just run B+ to the engine end of positive battery cable
You can use 2 smaller gauge wires each with 60amp fuse or larger gauge with 125amp or 150amp Mega fuse, they cost under $10 usually

Have you added any lights or ??? to electrical system?

Could be one of the longer Positive cables is starting to get internal corrosion, assuming you have looked at the ends so no surface corrosion.
This raises resistance so raises amp demand, higher temp of starter motor/engine when warmed up needs more amps as well, so could be the battery to starter solenoid wire that's the issue

Running Stock vehicle only uses maybe 45-50amps with all electrics on, so 60amp fuse on alternator should be fine
But if there was an issue, higher resistance in either positive cable, then 100+ amp alternator could have ramped up amps above 60 to compensate for it
So fuse blows now when it didn't before

 

[Ramcharger90]

 

[Ramcharger90]

Haven't added anything. just let the truck sit for 2 weeks in my garage. But I used it yesterday to pickup a 318 motor. Then after unloading it and fighting with it to crank that nonsense happened.

it was getting worse with the no crank slow crank.

 

[91stranger]

Why did you move the battery in the first place? Don't tell me it was so you could put a toolbox under the hood lol. IMO the ground in the last picture doesn't look very grounded.... I would scrape the paint off down to bare metal and then put the ground back on. Looks like it was just drilled into a painted frame so I don't know how much of a ground you are getting. What kind of wire connectors are you using? The good ones that have heat shrink or the cheap ones that can let in water? Just curious because of all the electrical tape.

 

[RonD]

Move the Alternator B+ connection to engine bay, that will solve the fuse blowing, assuming alternator is OK

Not sure on the slow cranking, try a load test
Disable spark or fuel, so no start
Put volt meter on engine bay battery cable and ground
Crank engine over and watch voltage, 9.5volts is barely OK, 9.8v-10.2volts is expected
If its low then could be amp restriction on + or - cables
OR
Starter motor is older, or has a problem and drawing too many amps now

 

[Ramcharger90]

Why did you move the battery in the first place? Don't tell me it was so you could put a toolbox under the hood lol. IMO the ground in the last picture doesn't look very grounded.... I would scrape the paint off down to bare metal and then put the ground back on. Looks like it was just drilled into a painted frame so I don't know how much of a ground you are getting. What kind of wire connectors are you using? The good ones that have heat shrink or the cheap ones that can let in water? Just curious because of all the electrical tape.

Heat shrink.

The paint was grind off behind the terminal.

And to make a cool air box. The truck was only getting hot air from the engine bay. And it would mess with the mass air flow sensor.

Not the picture of the finished results but gives you an idea.

 

[Ramcharger90]

Move the Alternator B+ connection to engine bay, that will solve the fuse blowing, assuming alternator is OK

Not sure on the slow cranking, try a load test
Disable spark or fuel, so no start
Put volt meter on engine bay battery cable and ground
Crank engine over and watch voltage, 9.5volts is barely OK, 9.8v-10.2volts is expected
If its low then could be amp restriction on + or - cables
OR
Starter motor is older, or has a problem and drawing too many amps now

It could be a bad alternator already, Rockauto cheap alternator what can I say.
Im gonna step up to 1/0 gauge cables and run the B+ cable to the 4 bar power block.
I dont really want that much voltage going to the starter solenoid.

 

[Curious Hound]

I dont really want that much voltage going to the starter solenoid.

You want full battery voltage going to the starter solenoid.

 

[Ramcharger90]

You want full battery voltage going to the starter solenoid.

On the hot side or the computer side of the solenoid? I will try it, I was under the impression that I needed the B+ cable of the alternator to the positive terminal on the battery.

Its an 98 explorer alternator in a 90 ranger. Using a 90 A9L so its a 4g alt on a 2g setup to my understanding.

 

[RonD]

On the hot side or the computer side of the solenoid? I will try it, I was under the impression that I needed the B+ cable of the alternator to the positive terminal on the battery.

Its an 98 explorer alternator in a 90 ranger. Using a 90 A9L so its a 4g alt on a 2g setup to my understanding.

Yes, you do want B+ to go to battery positive cable, but in this case in the engine bay not at battery's remote location, or its voltage has to travel 10ft back to battery and then 10ft more back to engine bay where its used by the vehicle


For many years a starter solenoid post was used as the 12volt distribution point for a vehicle
The larger Battery positive cable connected there, and then 3 to 6 other wires with it
Alternator B+ was one, usually via Fusible links
Engine Fuse box 12v wire was another
Cab fuse box 12v wire
Fuel pump fusible link
Main light switch fusible link
Power window fusible link

As time went by engine fuse box got more fuses and relays but the one starter solenoid post still distributed the 12volts, and just had Battery positive plus alternator B+ and one wire to feed the engine fuse box, which had 50 and 60 amp fuses for cab fuse box and ignition switch

But B+ was always hooked to battery positive thru a fusible link or mega fuse, like you said
Even when starter solenoid on inner fender was gone, there was usually still an inner fender mounted post for battery positive and 12v distribution

 

[Ramcharger90]

Yes, you do want B+ to go to battery positive cable, but in this case in the engine bay not at battery's remote location, or its voltage has to travel 10ft back to battery and then 10ft more back to engine bay where its used by the vehicle


For many years a starter solenoid post was used as the 12volt distribution point for a vehicle
The larger Battery positive cable connected there, and then 3 to 6 other wires with it
Alternator B+ was one, usually via Fusible links
Engine Fuse box 12v wire was another
Cab fuse box 12v wire
Fuel pump fusible link
Main light switch fusible link
Power window fusible link

As time went by engine fuse box got more fuses and relays but the one starter solenoid post still distributed the 12volts, and just had Battery positive plus alternator B+ and one wire to feed the engine fuse box, which had 50 and 60 amp fuses for cab fuse box and ignition switch

But B+ was always hooked to battery positive thru a fusible link or mega fuse, like you said
Even when starter solenoid on inner fender was gone, there was usually still an inner fender mounted post for battery positive and 12v distribution

So like this crude drawling?