Mechman Alternator FAQ

General Installation Tips

Higher output alternators, like Mechman units, require more effort to spin under load, which places added strain on the alternator drive belt. To ensure optimal performance:

Verify the alternator pulley is perfectly aligned with other engine pulleys to avoid belt slipping.
V-belt setups should have no more than 3/8 inch belt deflection, and serpentine belts should place the tensioner in the middle of its range.
For vehicles with poor belt “wrap,” consider installing an additional idler pulley to increase belt contact with the alternator pulley.
Higher amperage alternators (240–370 amps) should use at least a 6-rib serpentine or dual-V belt setup to minimize belt slip.

Calculating Pulley Ratio

To calculate your pulley ratio, divide the diameter of your crankshaft pulley by the alternator pulley diameter. For example, a 6-inch crank pulley and a 2-inch alternator pulley result in a 3:1 ratio, spinning the alternator three times the engine speed. G series alternators can handle up to 18,000 RPM, while S and Elite series alternators are rated to 20,000 RPM.

Battery and Cable Recommendations

When installing a Mechman alternator, it’s crucial to use properly sized cables:

Run a correctly sized positive and ground cable directly from the alternator to the battery terminals.
Ensure ring terminals fit snugly on bolts or studs to avoid heat buildup or potential fire hazards.

For high-wattage systems, follow these battery recommendations:

2,000 watts: upgrade the main battery
3,500 watts: main battery + 1 rear battery
5,000 watts: main battery + 1–2 rear batteries
7,500 watts: main battery + 3–4 rear batteries, 2 alternators
10,000+ watts: main battery + 4–5 rear batteries, 2 alternators

Frequently Asked Questions

Q: Will a high-output alternator damage my vehicle or battery?

A: No, as long as the batteries are in good condition and you install correctly sized charge and ground cables, your vehicle won’t be affected.

Q: Will a higher output alternator work with a computer-controlled alternator system?

A: Yes. Mechman alternators are compatible with computer-controlled systems. Some setups may require specific cable routing, and instructions will be provided if necessary.

Q: Will a high-output alternator increase my vehicle’s charging voltage?

A: Typically, no. Most Mechman alternators maintain OEM voltage, preventing harm to the vehicle. If higher voltage is needed, contact support to custom order an alternator with adjustable voltage.

Q: Will a higher output alternator reduce my fuel economy?

A: Higher amperage alternators require more horsepower under heavy loads, which may slightly impact fuel economy. However, when the alternator isn’t under heavy load, it operates similarly to a standard alternator.

Q: Can a 2-pin GM regulator be used for external regulation?

A: No. The GM 2-pin is ECU-controlled and not compatible with external regulation. Contact support for guidance on external regulator options.

Q: Can you spin an alternator backward?

A: Yes, but efficiency drops by around 40% without special rotors or fans. Custom solutions are available for reverse installations to ensure cooling and durability.

Q: Can my alternator recharge a completely dead battery?

A: While an alternator can charge a very low battery, it’s not recommended, as this can shorten the alternator’s lifespan. Use a dedicated charger to bring the battery to a full charge before relying on the alternator.

* Popular GM Truck/SUV Belt Part Number Applications *

Mechman Alternator FAQ | Installation & Usage Tips | Big Jeff AudioUpdated 6 months ago