More efficient alternator/power usage


Nez'sRanger

Member
Joined
Oct 6, 2018
Messages
86
Reaction score
14
Points
8
Location
Los Angeles, CA
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9L V6
Transmission
Manual
I have an 89 2.9 ranger. I notice that the alternator struggles to handle both my headlights and my heater on full blast. I intend to convert to full LEDs to reduce power use (and cause they're brighter and cooler).
I would like to know if there are any higher efficiency/newer alternators that I could fit on my 2.9?

While I'm on the topic of power consumption, are there any blower motors that suck less juice that would bolt on (little to no mods)?

My goal is largely fuel efficiency and lower strain on my engine. My 89 is practically my daughter, so anything to make her last longer! Haha!
 


Rock Auto 5% Discount Code: 248EE46702D889 Expires: October 1, 2019

snoranger

Well-known member
Supporting Member
ASE Certified Tech
Joined
Nov 25, 2007
Messages
4,033
Reaction score
351
Points
83
Location
Jackson, NJ
Vehicle Year
'79,'94,'02,'17
Make / Model
All Fords
My credo
I didn't ask for your life story, just answer the question!
The cheapest way for the blower motor to consume less power is also the easiest...

Reach down and turn the knob to a slower speed. :icon_rofl:

Seriously, the Ranger HVAC system has never let me down. It's way more powerful then that little cab needs. On my '90 supercab, once the engine was warmed up I'd leave it set to high temp, turn the blower off and open the back window. It would pull enough air through the heater that I didn't even need the blower running. (Obviously this didn't work too well in stop and go traffic, but worked great on the highway.)
 

kimcrwbr1

New member
Joined
Dec 6, 2009
Messages
5,990
Reaction score
34
Points
0
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
Do a good diagnostic on the charging system. The tech library has the proper procedure for testing it sounds like you have a issue that needs addressed. One good upgrade is run a 8g wire from the alternator housing directly to battery neg especially in colder weather. If your not running extra high amp draw accys the stock system should be just fine.
 

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,474
Reaction score
915
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
The cheapest way for the blower motor to consume less power is also the easiest...

Reach down and turn the knob to a slower speed. :icon_rofl:

Seriously, the Ranger HVAC system has never let me down. It's way more powerful then that little cab needs. On my '90 supercab, once the engine was warmed up I'd leave it set to high temp, turn the blower off and open the back window. It would pull enough air through the heater that I didn't even need the blower running. (Obviously this didn't work too well in stop and go traffic, but worked great on the highway.)
Profile says he's in LA, the highway is stop and go traffic.


It sounds to me like what you really need is just a new alternator. Those are some pretty classic symptoms of one that is old and weak and ready to be replaced.
 

snoranger

Well-known member
Supporting Member
ASE Certified Tech
Joined
Nov 25, 2007
Messages
4,033
Reaction score
351
Points
83
Location
Jackson, NJ
Vehicle Year
'79,'94,'02,'17
Make / Model
All Fords
My credo
I didn't ask for your life story, just answer the question!

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,474
Reaction score
915
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
I probably should have read that.
I was originally going to say that the truck was just objecting to being stuck in LA where it can't get going, but I figured that would be unhelpful.

Now that I think about it though, that may be a contributing factor. Low RPM alternators don't make full output.
 

RonD

Well-known member
Joined
Jun 2, 2012
Messages
13,293
Reaction score
285
Points
83
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
An Alternator has 3 Fields in its outer case, these 3 Fields generate AC voltage as the rotor is spun by the engine.
Each Field has 2 diodes that change the AC Volts to DC volts for use in the DC Voltage vehicle system.

A Field can fail or one of its diodes, this cuts alternators AMPs by 1/3

Common sign of this is dimming head lights at idle, no that is not suppose to happen, lol
No auto maker specs in an alternator that can't maintain vehicles full AMP load(everything on) at idle RPMs, i.e. 600-700 RPMs

Now if you add extra electrics then you need to change alternator to a high rated AMP unit


Alternators amp rating is when engine is at or above 1,500 RPMs, at warm engine idle, 650rpms, it will only have about 60% of its rating
So an alternator rated at 80 amps has about 45amps available at warm engine idle
If a Field fails.....................well dimming head lights, lol, but they get brighter as RPMs go up :)
 
Last edited:

Nez'sRanger

Member
Joined
Oct 6, 2018
Messages
86
Reaction score
14
Points
8
Location
Los Angeles, CA
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9L V6
Transmission
Manual
Thanks for the tips and advice!
I am planning on changing the alternator... Are there any units I can buy that have a greater power efficiency? I've read that most alternators have a 40% (or something) energy conversion efficiency. If possible, I'd like one that draws less power from my engine, but still makes the electricity I need for largely stock electronics. I know the power gain won't be noticable alone, but with the nickel and diming I'm doing, I'm hoping it will all add up in the long run. Same with the heater blower.
Thanks again!
 

Nez'sRanger

Member
Joined
Oct 6, 2018
Messages
86
Reaction score
14
Points
8
Location
Los Angeles, CA
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9L V6
Transmission
Manual
Even an alternator from a newer truck with a similar-sized engine?
 

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,474
Reaction score
915
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
The problem with the idea is that the 2.9 uses a fairly unique alternator. The 2.9 was the last Ford engine designed with a V-belt system, so anything newer is going to be designed for use in a serp system, which means that it will bolt down to a fixed point, rather than being able to be adjusted for belt tension like yours needs to be.

Here is a write up for installing a 130 amp unit from a T-bird 3.8 onto a 2.9. That's probably the best bang for your buck.
 

Nez'sRanger

Member
Joined
Oct 6, 2018
Messages
86
Reaction score
14
Points
8
Location
Los Angeles, CA
Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9L V6
Transmission
Manual
The problem with the idea is that the 2.9 uses a fairly unique alternator. The 2.9 was the last Ford engine designed with a V-belt system, so anything newer is going to be designed for use in a serp system, which means that it will bolt down to a fixed point, rather than being able to be adjusted for belt tension like yours needs to be.

Here is a write up for installing a 130 amp unit from a T-bird 3.8 onto a 2.9. That's probably the best bang for your buck.
V belts... Makes sense. Thanks for the cool bit of info! Guess I'll be sticking with a new/rebuilt oem alternator.

Definitely an idea on the 3.8... maybe down the road if I want to add more electronic features...
 

adsm08

Well-known member
Supporting Member
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
31,474
Reaction score
915
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
Well part of an alternator's physical load is what percentage of it's rating it's putting out. The stronger the field the more power you get, but the harder it is to turn the armature too.
 

Denisefwd93

Well-known member
Joined
May 20, 2015
Messages
2,230
Reaction score
52
Points
48
Location
South East PA
Vehicle Year
1994
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Total Lift
stock, may get leveling springs in front "somday"
Tire Size
235
I could be wrong, but do permanent magnet motors like blower motors on cars and trucks, draw "more" as they age/ loose magnetization?
 

ericbphoto

Old Redneck just wingin' it.
Supporting Member
U.S. Military - Veteran
TRS 20th Anniversary
Joined
Feb 7, 2016
Messages
2,350
Reaction score
303
Points
83
Age
55
Location
Piedmont, SC
Vehicle Year
1993
Make / Model
Ford Ranger
Engine Size
3.0L
Transmission
Manual
2WD / 4WD
4WD
Total Lift
6"
Tire Size
35"
My credo
In theory, theory and practice are the same. In practice, they are different.
I could be wrong, but do permanent magnet motors like blower motors on cars and trucks, draw "more" as they age/ loose magnetization?
In theory, yes. If the magnets are losing their field strength, that would weaken the motor and in the process it would draw more current. But I believe we could consider that to be a very, very rare occurrence. It takes extreme heat, or extreme electrical field or as n extremely long time for those magnets to lose an appreciable amount of their strength. I've been an electrician for over 37 years and haven't encountered that or even heard of it yet.

This message composed solely of recycled electrons. Go green!
 

Denisefwd93

Well-known member
Joined
May 20, 2015
Messages
2,230
Reaction score
52
Points
48
Location
South East PA
Vehicle Year
1994
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Total Lift
stock, may get leveling springs in front "somday"
Tire Size
235
20 some yrs ago I had an electric radiator fan and a heater blower fan motor lose their magnetics. (GM Pontiacs) Really surprised me too.
 


Top