FORD HYBRID ALTERNATOR
INSTALLATION INSTRUCTIONS
©2016 Tuff Stuff Performance Accessories, 9004 Madison Ave. Cleveland, Ohio 44102 www.tuffstuffperformance.com
CAREFULLY READ THESE INSTRUCTIONS BEFORE ATTEMPTING ANY MODIFICATIONS!
Proper installation of this alternator is the responsibility of the installer. Improper modification or installation will
void your warranty and may result in vehicle damage or personal injury. If you have any installation questions,
refer to your factory shop manual or call our Tech Service personnel at 216-961-1800 from 7am to 4pm EDT.
ALL ALTERNATORS REQUIRES A GOOD GROUND
In order for an alternator to charge properly, an alternator must be
grounded to the engine block. If an alternator has paint or clear-
coat on the mounting surfaces, it may not be grounded and will not
charge. For these reasons, many Tuff Stuff alternators include a
grounding tab that should be used to ground the alternator.
Alt Rating Wire Size Alt Rating Wire Size
75 Amps 8 gauge 150 Amps 4 gauge
100 Amps 6 gauge 200 Amps 4 gauge
CORRECT WIRE SIZE IS CRITICAL
It is very important to use the correct wire size to connect the
alternator to the battery. A wire size too small can allow the wire to
overheat, melt the insulation and cause a fire or worse. Depending
upon the maximum output of the alternator, use the following chart
as a minimum wire size guide. Wire size is based on 4’ battery
cables. Trunk mounted batteries require heavier gauge battery
cables - contact Tech Service for recommendation.
ROTATION SPEED
Alternators spin at approximately 2.5 times that of crankshaft RPM,
so an engine at a 700 RPM idle would spin the alternator at 1,750
RPM. Note that the maximum RPM of any Tuff Stuff alternator
should not exceed 18,000 RPM’s (7,200 engine RPM’s). There is
no need to worry about use of an underdrive pulley system or an
ignition regulator turn on with Tuff Stuff alternators. All Tuff Stuff al-
ternators charge at very low engine RPM’s. No other manufacturer
in the industry has an alternator that produces more amps at low
RPM’s than Tuff Stuff.Also note that Tuff Stuff 1-wire alternators are
bi-directional and will charge when spun in either direction
ALTERNATOR INSTALLATION INSTRUCTIONS
1 - Disconnect the ground cable from the battery.
2 - Disconnect all wire connections from the alternator and label
wires for future replacement.
3 - Remove alternator belt(s).
4 - Loosen alternator mounting and tension arm bolts.
5 - Hold the alternator securely while removing the mounting bolts
and spacers. Remove old alternator.
6 - Install new alternator and replace all mounting bolts and
spacers. Do not fully tighten bolts.
7 - Replace drive belt(s) on pulleys. Adjust V-belt tension. V-belts
should have ½” to ¾” play as light pressure is applied at
midpoint between pulleys.
8 - Tighten all alternator and bracket bolts.
9 - If installing an alternator with OEM wiring connections,
reconnect alternator wires and battery ground cable. If
installing a 1-wire alternator, see wiring instructions at
upper right.
10 - Make sure battery is fully charged before starting engine.
11 - Reconnect the ground cable, start the engine and using a VOM
meter, verify that the alternator is charging at least 13.8 volts @
1,000 engine RPM’s.
1-WIRE ALTERNATORS
1-Wire alternators require only 1-wire to operate. Simply run
one wire from the alternator ‘battery’ terminal to the positive
terminal of the battery or to the starter solenoid main lug,
which is connected to the positive battery post. Make sure
that the battery is fully charged. Reconnect the ground
cable, start the engine and using a VOM meter, verify that
the alternator is charging at least 13.8 volts @ 1,000 engine
RPM’s.
One wire alternators eliminate the unsightly factory
wiring harness and simplifies installation by using
only one wire for charging.
Simply connect one wire from the positive
battery terminal to the positive alternator
terminal. It’s that easy!
THIS ALTERNATOR SHOULD NEVER EXCEED 18000 RPM’s!
Alternator bearings and components are not designed for extremely high RPM’s. Tuff Stuff strongly recommends that you
calculate your pulley ratio to determine if your alternator will operate within the safe RPM range.
To calculate your alternator pulley ratio, divide the engine crankshaft pulley diameter by the alternator pulley diameter.
Using the ratio that you calculated, multiply that number by the highest anticipated engine RPM to determine the
maximum alternator RPM.
If your max calculation is greater than 18000 alternator RPM’s, increase the alternator pulley diameter or decrease the
crank pulley diameter to compensate. If changing the alternator pulley is not possible, use an engine rev limiter to control
maximum engine RPM’s.
Excessive RPM’s can cause the alternator fan to flex and contact the drive belt. Besides being unsafe, it could cause
property damage and/or personal injury. Other factors that will substantially increase the likelihood of alternator fan-to-belt
contact include:
LOOSE OR WORN BELTS
Loose or worn belts allow for movement and deflection which will decrease the gap between the fan and belt and increase
the likelihood of contact.
INCORRECT BELTS
Tuff Stuff supplied V-belt pulleys are designed to accommodate a 3/8” wide V-belt. Wider belts will not fully seat into the
pulley groove and will increase the likelihood of belt-to-fan contact. If the application requires a wider belt, use the original
alternator pulley instead of the supplied pulley.
ALTERNATOR BRACKETS ALIGNMENT:
Loose, damaged or misaligned alternator brackets can reduce the clearance between the alternator fan and belt.
Proper installation of this alternator is the responsibility of the installer. Improper modification or installation will void your
warranty and may result in vehicle damage or personal injury. If you have any installation questions, refer to your factory
shop manual or call our Tech Service personnel at 216-961-1800 from 7am to 4pm EDT.
ALTERNATOR PULLEY RATIO
Crankshaft pulley diameter ÷ alt pulley diameter = alternator pulley ratio
Example
6.75 ÷ 2.25” = 3:1 alternator pulley ratio
MAXIMUM ALTERNATOR RPM
Alt pulley ratio X Max engine RPM = Max alternator RPM
Example
3 X 6000 max engine RPM = 18000 max alternator RPM = SAFE
3 X 7000 max engine RPM = 21000 max alternator rpm = UNSAFE
WARNING
LIMITED WARRANTY
All Tuff Stuff Performance Accessories products are covered by a one year Limited Warranty,
which may be read or downloaded at www.tuffstuffperformance.com.
rev 1/19
