Product Summary
Many Engines, One Wire Alternator, Polished
- Designed to work as either a 1 or 3 wire operation
- Includes a single groove pulley that will accept a v-style belt
- Puts out 150 amp with 90 amps at idle, and 125 amps at cruising speed
- Case is hand buffed, polished, and high colored for beautiful polished finish
- Will fit GM vehicles from 1965-’85 with straight mount 6.61 inch bolt spacing
Powermaster 67293 GM 12SI 150 Amp Alternator, Polished details
Powermaster’s most popular GM alternator fits most models, 1965-’85 with straight mount 6.61 inch bolt spacing.
- Works as 1 or 3 wire operation
- Internally regulated
- Pulley included, single groove
- V-belt style
- 150 amp with 90 amps at idle, and 125 amps at cruising speed
- Hand buffed, polished, and high colored for beautiful polished finish
Powermaster Alternator FAQ’s (Link)
Charts
Warranties
Powermaster’s warranty is one year from the date of purchase on all street rod components, and 90 days for any component use for an off road or race application.
Powermaster will provide technical support regarding warranty claims and inquiries directly to the purchaser to help resolve any warranty claims or necessary technical support for warranty resolution. Component or components can be returned to Speedway Motors as long as the product is still under warranty.
All customer service inquiries pertaining to warranty and defect claims are to be handled by Speedway Motors if under one year street or 90 days race. If the product is out of warranty please contact Powermaster direct to discuss their repair and return program.
KEY SPECS |
|
---|---|
MFG. Part # | 67293 |
Brand | Powermaster |
One Wire Alternator | Yes |
Alternator Finish | Polished |
GENERAL |
|
Alternator Case Style | GM 12SI |
Alternator Amperage | 150 amp |
Voltage Required | 12-Volt |
Regulator Style | Internal |
Regulator Included | Yes |
Alternator Pulley Included | Yes |
Belt Type | V-Belt |
Belt Width | 0.375″ |
Alternator Brackets Included | No |
Overall Length | 6.25″ |
Sold in Quantity | Each |
Centerline of Holes | 6.61″ |
GTIN Code | 692209004462 |
Belt Included | No |
Pulley Style | V-belt |
Why Convert to A One Wire Alternator
A Simple Charging System Upgrade for Your Build Project
The one wire alternator has been around for several decades. Originally designed by GM for use in industrial and farm equipment, a clever hot rodder grabbed one and installed it on their ride and a simple and easy to use alternator upgrade was born. These original alternators were often a 10si Delco model (you can use our GM alternator guide to learn more) but today you can find direct fit one wire alternator conversion alternators for just about any engine or accessory drive system.
![One Wire Alternator](https://i0.wp.com/content.speedwaymotors.com/ArticleSectionImages/286082_ArticleSection_M_924b8069-e717-4267-b333-0cfc3224f8ef.jpg?ssl=1)
Speedway Motors offers one wire alternator options for most popular applications and we even offer accessory drive kits that include or accept one wire alternators if you need a complete serpentine drive solution for your project. Whatever you’re building or updating, if you’re looking for a GM 1-wire alternator conversion, a Ford 1-wire alternator conversion, or some other application, we have a 1-wire charging solution for you. Keep reading to learn about wiring 1-wire alternator applications and how easy a one wire alternator hook up is.
How To Wire a One Wire Alternator
The benefit of a one wire alternator conversion is the simplicity of its wiring needs. Unlike stock alternators that require additional wiring for the external or internal voltage regulator, the one-wire alternator variant simply needs a single wire from the alternator’s charging stud directly to the battery’s positive terminal, or a positive terminal junction connection, such as a starter solenoid on the fender or directly on the starter itself.
![One Wire Alternator Wiring Diagram](https://i0.wp.com/content.speedwaymotors.com/ArticleSectionImages/286083_ArticleSection_XXXXL_d2c9fb47-2aa1-4e4e-ad2f-da3caf3db764.jpg?ssl=1)
![Automotive Voltmeter Gauge](https://i0.wp.com/content.speedwaymotors.com/ArticleSectionImages/286084_ArticleSection_M_b8c4e385-d67c-4b12-a400-b30f330bc065.jpg?ssl=1)
If you’re converting a classic muscle car or hot rod that still has an external voltage regulator you disconnect the original wiring at the regulator. “It’s simple to hook up, you don’t need to use any of the original OE wires, and it has its own regulator built in, so it automatically regulates as needed,” Tuff Stuff’s Mike Stasko explains. Note: if the vehicle is equipped with an indicator light, the light will no longer be operative when converting to a 1-wire alternator. We recommend adding a voltmeter to your dash to monitor your charging system. One wire alternators are often used when a vehicle is being completely rewired, as most aftermarket wiring harnesses are configured for a 1-wire alternator to be used.
What Gauge Wire for One Wire Alternator Installation?
When we asked Tuff Stuff’s Mike Stasko about charge wire sizing this is what he had to say: “If you are going to add or use one of our higher amp alternators you have to use a larger diameter charge wire.” As such, the single charge wire that the typical one wire alternator conversion requires must be properly sized for the alternator’s maximum output capability. The larger the amp load the larger the wire diameter (smaller gauge size number) you must use. An 8 gauge wire will suffice for a standard 55-65 amp output, while 65-100 amp output should use a larger (numerically smaller) 6 gauge wire. Anything over 100 amps a 4 gauge wire must be used to provide enough support for the amperage output from the alternator.
![Two Gauge Battery Cable Set](https://i0.wp.com/content.speedwaymotors.com/ArticleSectionImages/286085_ArticleSection_M_89a234e8-a333-4173-91e8-b65db2b0cfc7.jpg?ssl=1)
These recommendations are considering a front mounted battery with a charge wire of seven feet or less in length. For trunk mounted battery setups, a 2-gauge wire should be the minimum to consider, with 1-0 wire used for alternators over 100 amps.
Does A One Wire Alternator Need to Be Grounded?
![Engine Accessory Ground Strap](https://i0.wp.com/content.speedwaymotors.com/ArticleSectionImages/286086_ArticleSection_M_b02c972c-644a-48c8-9d4b-17a825c84943.jpg?ssl=1)
It most certainly does, and in most cases the single wire alternator will ground through the alternator’s case to the mounting bracket/engine block. In some instances, paint, powder coat, or chrome finishes may hinder a quality ground connection. It certainly cannot hurt to add a ground strap from the alternator’s case to the vehicle’s frame and/or directly back to the battery’s negative terminal. This extra peace of mind will ensure your 1-wire alternator is properly grounded to function as it is intended.
Does A One Wire Alternator Need a Voltage Regulator?
The 1-wire alternator uses an internal voltage regulator that self-regulates the alternator’s output. There is no need for the traditional external voltage regulator found on many earlier generator and alternator charging systems found in early hot rods and cars up through the early 1970s. The self-sensing voltage regulator used in single wire alternators does not need a switched 12-volt exciter circuit wired to it like a 3- or 4-wire alternator with external regulator. This self-exciting voltage regulator only needs to see a certain engine rpm to connect the battery to the regulator and begin charging. This is often in the 1,200 rpm range.
If you have a carbureted engine with a high-idle cold start choke setting your 1-wire alternator should turn on immediately. However, in some applications where cold start idle is below the 1-wire alternator’s turn on threshold you may need to give a brief blip of the throttle to have the alternator “kick in” and begin charging. The good news is that once this happens there is no need to worry about the idle speed dropping below this turn on point and the alternator disconnecting or shutting down until the key is turned off. One exception to this is Tuff Stuff’s Silver Bullet line of heavy duty performance alternators rated to start charging at just 750 rpm.
Related to this initial charging rpm threshold will be the one wire alternator’s pulley ratio. Changing the pulley ratio on the alternator by slowing it down will generally keep a 1-wire alternator from charging. This can also produce a low voltage problem at engine idle speed depending on the amount of reduction. Alternators are usually designed to function at peak efficiency with a 3:1 pulley ratio. This is the recommended street pulley ratio and is used in most factory applications.
Will A Higher Amp Alternator Hurt My Car?
Having too low of an alternator output for the application will mean that your charging system will often use your battery’s reserve capacity to keep up with electrical demands. You should have enough charging system capacity that your battery is essentially used for starting the vehicle and for short term key-on engine-off electrical demands. We asked Tuff Stuff’s Mike Stasko to elaborate further: “You need to add up all the amperage and whatever that total is, typically you want 20 to 25 percent more amperage than what your total usage is.”