94 2.3L fusible link for alternator

Hi all, first post. My battery light came on in my ranger, kinda been expecting it as my bearing in alternator was getting loud. Popped in New alternator, but bait light on, and gauge showing 12v, confirmed with multimeter. Searching leads me to suspect the fusible link for alternator. Now just need to find it.

Am I correct in that it is the grey wire that plugs into the starter relay post on my driver inner fender? The other post was for a 94 w/ 3.0, wanted to make sure engine didn't affect wiring colors. Thanks

Welcome to TRS

Yes, 1994 used Grey fusible link connected to Battery Post on Starter Relay.
There may be more than 1 Grey Fusible links on that post.

If you have a volt meter, or 12v test light, you can test if an alternator fuse or fusible link is blown

Key OFF tests
B+ is the connection on the back of the alternator, Black/orange stripe wire, its connected to the Grey fusible link.
Test if it has 12volts at the alternator, if so fusible link is OK

Unplug 3 wire Voltage regulator connector
The Yellow wire is connected to a 15amp fuse in engine fuse box, fuse #20, 15amp
Yellow wire should also have 12volts, if not 15 amp fuse is blown.

Light Green/red stripe wire comes from the Battery Light, should be 0 volts, key OFF
Turn key on
Light green wire should now have 12volts, if not fuse in Cab Fuse box is blown, don't have a # for that one, should be 7.5 to 10amp fuse

Can I use an in line fuse to replace the fusable link, or well that be bad? And if so, what amp fuse should I use?

Thanks for response.

Fusible link would be better

Or get a Mega Fuse, 80-100amp

Problem with regular fuses on the B+ wire is that they will blow a few times a year because AMPs change so fast after startup so fuse heats up and separates(blows) when that happens, B+ wire goes from 0 amps to 50 amps in a second or two when engine starts up, then AMPs can spike now and then from voltage regulator fluctuations

Fusible links and Mega Fuses can absorb the heat, up to a point, before they "blow" which is why they are used for this circuit

Fusible links or mega fuses usually "blow" because B+ wire shorts to Ground or alternator does internally, so full Battery AMPs(400+) blow the fuse not the alternator AMPs

I have an inline megafuse for amplifier....what amp megafuse would be safe?

Thanks Ron

80 or 100amp

Thanks Ron!! I'll let u all know what I find...

Damn.....have 80A mega fuse, but no holder....what size inline fuse would work until I pick one up?

Nvm.. .bought the correct holder at walmart.

Ok....replaced it....getting 12v @ b+ now....but still not charging.....bum alternator?
Got to ch3ck 3 wire harness next I guess.....

Yes, check yellow wire, it should also have 12v

RonD said:

Yes, check yellow wire, it should also have 12v

Click to expand...

i have an 04 ranger 3.0 if that fuse link blew on mine would it cause my truck to kill the battery in a coupke mins of running while the alternator is giving 13.5-14 volts


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Wsljr2208 said:

i have an 04 ranger 3.0 if that fuse link blew on mine would it cause my truck to kill the battery in a coupke mins of running while the alternator is giving 13.5-14 volts


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Click to expand...

???

Car batteries have 12.3-13.0volts
Alternators output 13.5-14.9 volts

If alternator is not connected to battery, fusible link blown, then system wide voltage would show 12v, battery voltage, so under 13v, engine off or running
This would not effect running engine until battery voltage drop under 10v usually, which would take a few hours in the daytime, with headlights on then not that long, maybe 45min/hour, depends on how old battery is

It is "safe" to fast charge a car battery at 2.0-2.3volts above its current battery voltage, but only for about 10 min max.
Then you need to drop to a maintenance charge, 1.0-1.3volts above current battery voltage.

That's what voltage regulator in the alternator does
Just after starting engine(takes 60-75amps) battery is drained
Voltage regulator will run its voltage above 14volts to fast charge battery in case restart is needed, but that should only last a few minutes, 10min. max or battery fluids can start to evaporate, even sealed batterys.

Then voltage regulator drops to under 14volts, 13.5-13.8v usually, this keeps battery charged but won't "cook it".

Car batteries can fail out of the blue, there are about 50 plates inside a car battery, if any get shorted then battery is self draining.
Shorting can occur from over charging or draining battery too low.

But in general the plates inside start to lose functional area each time they are used normally, i.e. starting the engine, when enough area is lost then not enough AMPs can be stored, so battery can't deliver the 60-75amps needed to start the engine
And you get the "click, click, click" of starter relay opening and closing because there are not enough AMPs to get starter motor turning.
i.e. starter relay closes, start motor is connected to battery, draws 60amps, battery doesn't have 60amps so battery voltage drop below 8volts and relay OPENS, which cuts connection to starter motor and voltage pops back up to 12v and relay closes again, click, click, click, ect......

5-7 years is life expectancy of car batteries, but if they are over charged or drained too low then expected life is less

would it be possible for 2 old batt and 1 newish batt it hasnt been used just sitting in garage for 2 years to all have gone bad dead cells or anything else that can happen

RonD said:

Yes, check yellow wire, it should also have 12v

Click to expand...

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Wasn't able to do anything else, had to pack....at beach for few days. Will check yellow when I get back...