Z31 Alternator Upgrade

If you are thinking about swapping in a larger alternator into your Z car, here is a little background on what is needed to do this install.

Reasons to swap the alternator

The #1 reason: The Maxima alternator outputs 90 amps compared to the Z31's stock 70 amps. People have swapped in many different Nissan model alternators, from the Maxima we are talking about here to the 350Z and even Nissan Titian Alternators.

Extra electrical power for high-wattage stereo systems.
Supports the use of electric fans instead of the stock clutch fan.
Improved capacity for other modern electrical accessories and upgrades.

If you’re adding electrical upgrades to your Z31, the Maxima alternator swap is a tried-and-true solution for reliable power as it was the first one done. Other model alternators will be very similar but the adjusting bracket and mounting bracket may need modifiation or replacement to fit correctly.

Items Needed

1990-1991 Maxima Stock Replacement Alternator AutoZone Part #14661 DURALAST — $87.96
10mm socket
12mm socket
14mm socket
Ratchet
12mm open/box wrench
10mm open/box wrench
Breaker bar
Grinder
Alternator belt (Non-turbo V-belt) Advance Auto Part #17371
Alternator belt (Turbo serpentine belt) Advance Auto Part #5040410
Jack and jack stands

Removal

Disconnect the negative battery cable.
Remove the 4 nuts holding the fan & clutch onto the fan pulley (10mm open wrench).
Be careful not to drop the lock washers.
Remove the 10mm bolt holding the fan shroud to the air filter support.
Pop the fan side of the shroud off the radiator side and remove the fan and shroud together.
Put 2 of the fan’s nuts back on the studs to keep the pulley from falling off the water pump.
Jack up the car and support it with jack stands.
If your car still has the splash shield, remove it by taking out the 10mm bolts or Phillips head screws (varies by year).
Remove the four 14mm sway bar-to-body bolts and let the sway bar hang from the end links.
Remove to drop swaybar. Two bolts per side. Sway bar lowered out of the way.
Remove the alternator drive belt by loosening the tensioner nut (12mm) and then the locking bolt (12mm).
Turbo Models 84-86 Non Turbo
Remove the top bolt holding the lower alternator bracket to the motor for extra clearance.
From the rear of the alternator, remove the one retaining bolt and unplug the connector.
On the front of the alternator, remove the remaining retaining bolt. Turn the alternator around for access to the last bolt holding the wiring.

Differences between the two

If you have a non-turbo Z31: The Maxima alternator uses a ribbed (serpentine) belt, while the stock alternator uses a V-belt. You have two main options:

Option 1: Swap to the ribbed belt setup by changing the crankshaft pulley (to a turbo model) and installing the appropriate serpentine belt.
Option 2: Reuse your V-belt pulley by enlarging its center hole to fit the Maxima alternator shaft, and add a spacer for proper alignment.

After this, the Maxima alternator will bolt in directly to non-turbo Z31s.

If you have a turbo Z31: You may need to grind away a small section of the inside of the alternator tensioner bracket, since the Maxima alternator housing is slightly larger. This is the only modification needed—otherwise, it's a direct swap.

Pro Tip: Other Nissan alternators—including units from the 350Z, Quest, and Titan—can be adapted for use in the Z31. However, you’ll need to modify the alternator bracket and adjuster to fit, and higher-output models may require additional custom work. Always test-fit and check clearances before final installation.

Sources Used

Thumper300zx
Work Done To SecaDriver's 88 turbo