• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Alternator removal / installation


Vexarana

New Member
U.S. Military - Active
Joined
Jan 28, 2012
Messages
84
Reaction score
0
Points
0
Vehicle Year
1991
Make / Model
Ford
Transmission
Manual
Hey all,

So I am in the middle of an alternator swap because my old one does not support some audio upgrades I have done.

Problem is, nothing I could find online talks about the alternator that my truck has in it.

Here is a photo album of the old one and the new one.

The wires that are still connected are the problem, obviously. Not to mention that the new alternator (supposed to be a drop in) has different wires running to it. So that easy part is now hard as well.

Anyone know how the hell to get the old one out? Running new wires isn't THAT big a deal I suppose but everything I can find says that the side-plug alternators (this one?) and the rear plug alternators (new one) should be.. well, plugs. Not fixed.
 


Rock Auto 5% Discount Code: F9A1A579ACFAD1: October 1st, 2021

NGillespie10

New Member
Joined
Dec 17, 2015
Messages
4
Reaction score
0
Points
0
Vehicle Year
1995
Make / Model
Ford
Engine Size
3.0L
Transmission
Automatic
I just replaced the alternator on my '95 XLT 3.0L. Not sure if it's exactly the same, but based on the look of the alternator it seems very similar to what I replaced.

Loosen the serpentine belt and remove it from the alternator pulley.
Remove the three bolts holding the alternator in.
Disconnect any wires or plugs attached to it.

Not sure exactly what you were looking for, but it's one of the more basic replacements.
 

jeremysdad

New Member
ASE Certified Tech
Joined
Nov 19, 2014
Messages
354
Reaction score
3
Points
0
Vehicle Year
1993
Make / Model
Ford
Transmission
Manual
Last edited:

Vexarana

New Member
U.S. Military - Active
Joined
Jan 28, 2012
Messages
84
Reaction score
0
Points
0
Vehicle Year
1991
Make / Model
Ford
Transmission
Manual
The current alternator doesn't have a plug. I tried to look up the "part number" which is just one of the numbers off the barcode on it and it pulls nothing up. But yet it says Motorcraft. The thing that is killing me is that it ISN'T a plug. I have tried yanking, pulling, prying, and wiggling that thing and it is solid. I can't quite see inside it to see WTF is going on though. It doesn't look like the 95 / 130 Amp ones nor the old pre 90's rangers either.
 

pjtoledo

Well-Known Member
Supporting Member
U.S. Military - Veteran
Joined
Oct 5, 2007
Messages
3,347
Reaction score
972
Points
113
Location
Toledo Ohio
Vehicle Year
20002005199
Make / Model
Fords
Engine Size
3.0 2.3
My credo
get outta my way, I'm falling!
that round thing that's all chewed up is not a plug, its the hi current line terminal exiting the alternator, it doesn't come out.
 

Vexarana

New Member
U.S. Military - Active
Joined
Jan 28, 2012
Messages
84
Reaction score
0
Points
0
Vehicle Year
1991
Make / Model
Ford
Transmission
Manual
But on the newer alternators, it is a plug, right? Cause there were no wires to cut when we pulled the 130 amp one out.

So I need to get a harness for the new one? Does anyone know the P/N for it?
 

Big Jim M

New Member
Joined
Apr 18, 2008
Messages
2,728
Reaction score
28
Points
0
Age
84
Location
Austin
Vehicle Year
2002
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
What? Do you think that harness CAME with the alternator attached? Of course that is a PLUG! Any of my daughters could pull it out! Hell even my sister could.
Get real mean with it sonny.
Big Jim
 

Vexarana

New Member
U.S. Military - Active
Joined
Jan 28, 2012
Messages
84
Reaction score
0
Points
0
Vehicle Year
1991
Make / Model
Ford
Transmission
Manual
Unless it welded itself on there, it's not a plug. Regardless, I still need the plugs (or harness) for the new alternator. Can I cut and splice these wires or do I have to pull the whole thing? I'm not sure what wire does which because it doesn't match the wiring diagrams I have in my Haynes.
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
20,128
Reaction score
3,951
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Have a look here: http://www.therangerstation.com/tech_library/alternator.shtml

There are pictures of your 1991, and up alternators, 95 amp model and the 130 amp model.

The Ford alternator will have a terminal on the back or side with a nut, this is the B+ connection and uses the larger wire(s).
Then a 3 wire connector(that does unplug), this is for the internal voltage regulator
There will also be a single plugin on the alternator for a short wire coming off the 3 wire connector harness.

You do need to hit a wrecking yard or parts store with your new alternator in hand to get the correct connector, no part number will help.
Also get wire connectors to splice the new connector to your existing wires.
So yes you can cut the wires, but battery MUST BE DISCONNECTED!!!!!!!!!

The wiring is very easy.


As far as why you are doing this.
If you have installed a subwoofer that is causing an electrical issue then higher amp alternator won't really help that, won't hurt, it is just not the issue.
Subwoofers draw more watts than available when they produce a low frequency "note", this will cause dimming lights and odd electrical issue in cars/trucks.

Only solution are capacitors made for automotive used, and subwoofer use specifically.
Subwoofer doesn't need constant high watts, just has a high demand to make the sub-sonic "beats", and this is done by adding simple amp storage devices, capacitors.
Capacitor stores amps and then releases them when demand draws more amps than are available on incoming power wire.

Think of it as a water storage tank in your house, your incoming water from city is 1 gallon a minute, storage tank holds 30gal.
If you turn on all the taps in the house the use is 5gal a minute, without storage tank, taps would be down to a trickle in no time at all.
Storage tank would be empty in 6 minutes but would you have ALL the taps on for 6 minutes, no you wouldn't(and subwoofer isn't drawing max watts all the time either)
So say you drain 15 gallons of water out of storage tank and shut off the taps, 15 minutes later tank is full again, at 1 gallon a minute from water supply.
A larger alternator is like increasing the in coming water supply, so you double it to 2 gal a minute, or ever triple it to 3gal a minute................helps but won't solve the problem, of needing 5 gal a minute.
Larger storage tank would if there was a problem.

The capacitor stores amps until needed then refills when not needed.
A 1,000watt subwoofer running on 12volts power could need 83amps on a low bass note.
Even a 200amp alternator couldn't provide that unless engine was at 3,000+ RPMs at the time.
Alternators only provide rated max amps at high RPMs, they are usually about 1/2 at idle, and other systems in the truck are also using amps.
 
Last edited:

Big Jim M

New Member
Joined
Apr 18, 2008
Messages
2,728
Reaction score
28
Points
0
Age
84
Location
Austin
Vehicle Year
2002
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
So what you are saying

Have a look here: http://www.therangerstation.com/tech_library/alternator.shtml

There are pictures of your 1991, and up alternators, 95 amp model and the 130 amp model.

The Ford alternator will have a terminal on the back or side with a nut, this is the B+ connection and uses the larger wire(s).
Then a 3 wire connector(that does unplug), this is for the internal voltage regulator
There will also be a single plugin on the alternator for a short wire coming off the 3 wire connector harness.

You do need to hit a wrecking yard or parts store with your new alternator in hand to get the correct connector, no part number will help.
Also get wire connectors to splice the new connector to your existing wires.
So yes you can cut the wires, but battery MUST BE DISCONNECTED!!!!!!!!!

The wiring is very easy.


As far as why you are doing this.
If you have installed a subwoofer that is causing an electrical issue then higher amp alternator won't really help that, won't hurt, it is just not the issue.
Subwoofers draw more watts than available when they produce a low frequency "note", this will cause dimming lights and odd electrical issue in cars/trucks.

Only solution are capacitors made for automotive used, and subwoofer use specifically.
Subwoofer doesn't need constant high watts, just has a high demand to make the sub-sonic "beats", and this is done by adding simple amp storage devices, capacitors.
Capacitor stores amps and then releases them when demand draws more amps than are available on incoming power wire.

Think of it as a water storage tank in your house, your incoming water from city is 1 gallon a minute, storage tank holds 30gal.
If you turn on all the taps in the house the use is 5gal a minute, without storage tank, taps would be down to a trickle in no time at all.
Storage tank would be empty in 6 minutes but would you have ALL the taps on for 6 minutes, no you wouldn't(and subwoofer isn't drawing max watts all the time either)
So say you drain 15 gallons of water out of storage tank and shut off the taps, 15 minutes later tank is full again, at 1 gallon a minute from water supply.
A larger alternator is like increasing the in coming water supply, so you double it to 2 gal a minute, or ever triple it to 3gal a minute................helps but won't solve the problem, of needing 5 gal a minute.
Larger storage tank would if there was a problem.

The capacitor stores amps until needed then refills when not needed.
A 1,000watt subwoofer running on 12volts power could need 83amps on a low bass note.
Even a 200amp alternator couldn't provide that unless engine was at 3,000+ RPMs at the time.
Alternators only provide rated max amps at high RPMs, they are usually about 1/2 at idle, and other systems in the truck are also using amps.
A trip back to the audio store should cure his ailments with the aftermarket sound system. Simply installing the proper electric items to make the audio work as designed will solve the problem. AND leave the original alternator alone and it should be good.
Big Jim
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
20,128
Reaction score
3,951
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Oops forgot the wires.

B+ terminal, with nut on it, wire(s) goes to Battery positive, usually on the Starter Relay post with battery "+" cable, but can go to 60amp fuse in engine fuse box

The 3 wire plug-in will have A, S and I labels

"A" usually goes to the Fuse box in engine bay(yellow wire on most Fords), can be a 60amp fuse or 15amp on later models, the wire will have 12volts all the time, same as B+ wire, it can also hook to Starter relay.
B+ or "A" wires that are hooked to Starter Relay on fender will have Fusible Links in line, these are Slow Blow fuses that should NOT be bypassed.

"S" wire is the short loop wire(usually white wire) that will plug-in next to 3 wire connector, you will see a spade sticking out of alternator where S wire plugs in

"I" wire is the ON/OFF switch for alternator, usually a light green wire, it runs to the dash board and hooks to the Battery Light in the dash and if so equipped the Voltage Gauge in the dash.
"I" wire will only have 12volts when Key is On, this turns on the voltage regulator in the alternator.
If this wire had 12volts when engine was off the battery would drain fairly fast.
Battery light comes on when key is turned on, this is because alternator is not generating power so is a "ground", when engine starts alternator generates power so Battery light now has 12volts on each side, so bulb goes off.
If alternator quits generating power or it's power output drops below 12volts Battery light will come on
 

Patriot1776

New Member
Joined
Feb 5, 2011
Messages
42
Reaction score
1
Points
0
Location
Foothills of the Cascades
Vehicle Year
1992
Make / Model
Ford
Engine Size
4.0 OHV
Transmission
Automatic
RonD- you are a veritable encyclopedia of knowledge on the alternator issues. I wish I would have seen your explanation months ago. It could have saved me many headaches. When I couldn't figure out why my battery drained so fast when the truck was turned off, I finally brought it to a mechanic shop and had them fix it. I think I understand a mite better what they were trying to explain to me now that I've read your explanation.

Sent from my SM-G900V using Tapatalk
 

aspevacek

Member
Supporting Member
U.S. Military - Veteran
Joined
Jul 10, 2009
Messages
331
Reaction score
3
Points
18
Location
Harrisburg PA
Vehicle Year
97
Make / Model
Ford
Engine Size
4.0 OHV
Transmission
Automatic
Cap or a second battery (deep cycle) dedicated to the audio system would be the route to take for the issue, the second battery would create the need for an isolator to ensure a constant charge going to it.
 


Top