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  1. How do I hook up a one wire alternator?
     
  2. When to use a one wire alternator?
     
  3. I noticed that my Powermaster one wire alternator has to be revved up to get the alternator to come on. Why?
     
  4. Will aftermarket underdrive pulleys (power pulleys) affect the output of the alternator?
     
  5. How do I hookup a one wire alternator if my stock alternator was an externally regulated alternator? What do I do with the regulator and wiring harness?
     
  6. My dash light does not work after I installed my one wire alternator. How do I get my dash light to work?
     
  7. I noticed that my voltage gauge reads 13.6+ going down the road, but when I am at a stop or just idling, the voltage drops to 12.5V. Why?
     
  8. Will a higher amp alternator hurt my battery or charging system?
     
  9. How can I hook my one-wire alternator up as a three-wire alternator?
     
  10. I noticed the Proof of Performance tag rates the output at 2400 RPMs. Is this engine RPMs?
     
  11. My stock Ford alternator had two wiring harnesses that plugged into it. How do I hook up this one wire Ford upgrade alternator? What do I do with the two wiring harnesses?
     
  12. Is there any modification I need to do to my wiring to install a high amp alternator?
     
  13. The pulley on my stock alternator had only 4 or 5 grooves (serpentine) and this high amp alternator has 6 grooves (serpentine). Can I still use this alternator? Will it mess up my belt(s)?
     
  14. The Powermaster high amp alternator is bigger than my stock alternator - will I be able to install it?
     
  15. The stock wiring harness on my '96 - '99 Chevy/ GM truck will not plug into the 200 amp upgrade alternator. It is oval shaped and the plug on the alternator is square. What do I do?

How do I hook up a one wire alternator?

Simply run a charge wire from the battery terminal on the alternator to the positive terminal on the battery. The onw-wire regulator is a self-exciting regulator, meaning that it has sensing ciruitry for alternator rotation. As the alternator starts to spin, this circuitry connects the internal voltage regulator to the battery and turns the alternator on. When the alternator comes to a complete stop, this same circuitry turns the alternator off.

 When to use a one wire alternator?

Powermaster early style Delco alternators will work either way - as a one wire or OEM style. The main difference between a one wire and an OEM is the method used to energize or turn on the alternator. An alternator using the OEM style is turned on with the ignition switch. The one wire design is energized with a special sensing cicuit built into the internal voltage regulator. This circuit senses the rotation of the alternators rotor. The rotor must turn at sufficient speed to trip the circuit, starting the charging process. This turn-on speed is affected by several things and is typically higher with certain high amperage alternators. Once this circuit is tripped, the alternator will charge at all speeds, even very low ones, until the alternators rotor comes to a complete stop. At that point, the circuit will shut off and wait for the process to be repeated. What this means for the consumer is that in some applications the engine must be revved to 1200 or 1400 RPMs to turn the one wire alternator on. If the wiring harness is available and this characteristic is annoying, then Powermaster alternators can be plugged in like the stock unit and operated with the ignition switch.

 I noticed that my Powermaster one wire alternator has to be "revved up" to get the alternator to come on. Why?

A one wire alternator has a turn on point (sometimes called cut in, which is typically 1200 engine RPMs). This is the speed where the internal sense circuitry connects the battery to the voltage regulator, thereby turning the alternator on. Once the voltage regulator turns on, the alternator will remain on and charging until the engine comes to a complete stop. If the engine idle speed and pulley ratio combination do not allow the alternator to come up to this point during starting, the engine will have to be revved up to turn the one wire alternator on. The sense circuitry in the one-wire regulator can be bypassed to excite the alternator as soon as the ignition switch is turned on. This is called three-wire operation. This means the alternator will not be dependent on reaching a certain turn on RPM.

Will aftermarket  underdrive  pulleys (power pulleys) affect the output of the  alternator?

YES, especially when using a one-wire alternator. Changing the pulley ratio of the alternator by slowing it down will generally keep the one wire regulator from cutting on. This may also produce a low voltage problem at engine idle speed, depending on the amount of reduction. Powermaster alternators are tested with a 3:1 pulley ratio in mind. This is the recommended street pulley ratio, and the ratio used in most OE applications.

 How do I hookup a one wire alternator if my stock alternator was an externally regulated alternator? What do I do with the regulator and wiring harness?

The only thing required to electronically hookup a one wire alternator is to run a charge wire from the battery terminal on the alternator to the positive terminal on the battery (or any positive battery source). The external regulator can be either totally removed from the firewall or left in place. If left in place, be sure to disconnect the wiring harness from the regulator. The wiring harness has to be disconnected from the regulator or the indicator light on the dash will remain on. NOTE: If the vehicle is equipped with an indicator light, the light will no longer be operative. Please see the following question.

My dash light does not work after I installed my one wire alternator. How do I get my dash light to work?

Some Powermaster alternators have an indicator light drive. The indicator light wire from the stock wiring harness has to be connected to this terminal of the one wire alternator. If the you had an OE externally regulated alternator, then use a conversion wiring harness (part # 150). If you had an internally regulated alternator with the two spade wiring harness connector, simply remove the black rubber cover on the side of the Powermaster alternator and plug the harness in. (PLEASE NOTE: This applies only to part #s 17294, 37294, etc. and not to part # 178021, etc.)

 I noticed that my voltage gauge reads 13.6+ going down the road, but when I am at a stop or just idling, the voltage drops to 12.5V. Why?

This could be caused by several things. First, the pulley ratio may cause the alternator to spin too slow for these driving conditions. Using underdrive or power pulleys on a street application can cause this problem because the pulley ratio becomes less than the typical street ratio of 3:1. If the pulley ratio IS 3:1, another possibility is that the alternator is too small or not powerful enough at slow speed for the amp load of the vehicle. Also, the charge wire could be too small or the ground path may have high resistance. The gauge could be out of calibration. Check the voltage directly at the alternator with electrical loads on to determine if the problem is the alternator or the path to the battery.

 Will a higher amp alternator hurt my battery or charging system?

No. A good rule of thumb is that more amps are not harmful, but more voltage is. If you look at electrical power like water, amperage is equivalent to the volume of water, and voltage is equivalent to water pressure. More amperage is like having a larger pool of water to draw from.

How can I hook my one-wire alternator up as a three-wire alternator?

Some Powermaster one wire alternators (i.e., pn/n's 17127, 17294, 37294, 47294, 8002, 58005) can be hooked up as a three wire ...IF the vehicle is equipped with the two spade GM or aftermarket wiring harness. The Powermaster one-wire alternators have a black plug cover on the side of the alternator. This can be removed and the GM or aftermarket two-spade wiring harness can be plugged in for three-wire operation. See your alternator instruction sheet for further details.

I noticed the Proof of Performance tag rates the output at 2400 RPMs. Is this engine RPMs?

No, this is alternator rotor speed. To determine the engine RPM's, calculate the pulley ratio. The typical street pulley ratio is 3:1. Therfore, 2400 alternator RPMs is 800 engine RPM's (2400/3=800).

My stock Ford alternator had two wiring harnesses that plugged into it. How do I hook up this one wire Ford upgrade alternator? What do I do with the two wiring harnesses?

The only thing required to hookup the one-wire alternator is a charge wire from the battery terminal on the alternator to the positive terminal of the battery. The two stock wiring harnesses simply need to be secured out of the way. See your instruction sheet for further details.

Is there any modification I need to do to my wiring to install a high amp alternator?

Powermaster recommends increasing the size of the charge wire from the alternator to the battery. Recommendation regarding the proper wire gauge can be found here.

The pulley on my stock alternator had only 4 or 5 grooves (serpentine) and this high amp alternator has 6 grooves (serpentine). Can I still use this alternator? Will it mess up my belt(s)?

No. There are several different serpentine pulleys available for late model alternators. Typically, the pulley off the stock alternator will fit on the Powermaster high amp alternator, if you prefer using the stock pulley. Powermaster high amp late model alternators come with a small, 6 groove serpentine pulley for a universal fit. If the stock alternator had a 4 or 5 groove pulley, the belt can still be used on the 6 groove pulley.

The Powermaster high amp alternator is bigger than my stock alternator - will I be able to install it?

If you have purchased a Powermaster alternator based on Powermasters application guide, then the alternator shold fit in the stock brackets (unless otherwise noted), even though it may be larger in diameter. Powermaster endeavors to provide upgrade alternators that are bolt-on replacements. In many cases, there is alarge size alternator that will work in the factory brackets.

The stock wiring harness on my '96 - '99 Chevy/ GM truck will not plug into the 200 amp upgrade alternator. It is oval shaped and the plug on the alternator is square. What do I do?

You will need a conversion wire harness adapter - part # 160.

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