Running dual compressors?

[Jayschevy]

I currently am running 1 compressor with a 5 gal tank on my truck and would like to add a second compressor. My question is if I add a 2nd compressor will I need to add anything else such as another battery or different alternator. My current alt I believe is a 55 or 60 amp alt and 1 compressor may pull up to 20 amps. Will my current alt be able to handle another compressor? What is everyone doing that have dual compressors?

Thanks

[king-918]

Not a bad idea to upgrade if your compressors pull 40amps out of a 60 amp system you will strain/ starve your electrical system. Oh yeah add another relay
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[Pro Performance]

Yeah, agreed, it would be a good idea to upgrade the alternator to have sufficient power when running. What compressor model do you have now? Are you planning to add the same model compressors?

Also, I would recommend another relay for the new compressor. When running dual compressors, each should be wired on it's own 40A relay.

We are an authorized VIAIR dealer. Let me know if we can help you out.

Travis

[Jayschevy]

so instead of running 2 batteries i should run a hi amp output alternator instead?

[Pro Performance]

Yes, it is more important to have the hi-amp alternator putting out the amperage you need for both compressors. This way, it won't have to rely on the batteries to take up the slack. You can run dual compressors on a single battery system.... the amp load will be on the alternator. Your truck should be running when the compressors are running in order to get correct voltage (13.8 charging voltage), and to not drain the batteries.

2 batteries is good to have, but I wouldn't say it is necessary.

[king-918]

You can run two batteries but they need to be charged to
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[Jayschevy]

Anyone know where I can get a hi amp alt for my 71 C10?

[Pro Performance]

I can get the Powermaster if you are interested. Runs about $150.

Another option would be the Summit Racing brand 100A alternators, which are on sale for $81. Not a bad deal.

http://www.summitracing.com/parts/SUM-811001/

[Jayschevy]

Originally Posted by Pro Performance

I can get the Powermaster if you are interested. Runs about $150.

Another option would be the Summit Racing brand 100A alternators, which are on sale for $81. Not a bad deal.

http://www.summitracing.com/parts/SUM-811001/

Whats the amperage on the Powermaster one?

[Jayschevy]

Also, if I run the 100A alts will I need to upgrade any wiring sizes?

[502ms]

Originally Posted by Pro Performance

Yeah, agreed, it would be a good idea to upgrade the alternator to have sufficient power when running. What compressor model do you have now? Are you planning to add the same model compressors?

Also, I would recommend another relay for the new compressor. When running dual compressors, each should be wired on it's own 40A relay.

We are an authorized VIAIR dealer. Let me know if we can help you out.

Travis

I have all of the above, but I have the 60A alternator. I have my compressors running on a switch that can be toggled on/off. If you ran two batteries, is an isolator needed for the charging of the second battery? I have two ViAir compressors as well.
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[Pro Performance]

The power master was a 100A. They make a 140A, but it costs $195.

You might want to upgrade the charging wire to the battery (or starter), depending on how yours is wired currently. Just make sure to run the correct gauge wire to the compressors. The longer the distance the larger gauge wire you need.

[502ms]

I have upgraded my wiring on whole truck with the Painless harness...so, same question
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[Pro Performance]

Originally Posted by 502ms

I have all of the above, but I have the 60A alternator. I have my compressors running on a switch that can be toggled on/off. If you ran two batteries, is an isolator needed for the charging of the second battery? I have two ViAir compressors as well.
Posted via Mobile Device

If the batteries are linked together, then they both should charge together, since they are acting as one system. As far as I know and my knowledge of running a 2 battery system.

[king-918]

In car stereo its called the BIG 3. upgrade battery, wires, and Alternator. if you isolate a battery it will still need to be charged. there is really no cheap way out. if you don't upgrade the weakest part will fail just a matter of time

[502ms]

Yes, I agree. Since I've updated all of the above, I need a more powerful alt...will do.
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[Jayschevy]

Originally Posted by Pro Performance

The power master was a 100A. They make a 140A, but it costs $195.

You might want to upgrade the charging wire to the battery (or starter), depending on how yours is wired currently. Just make sure to run the correct gauge wire to the compressors. The longer the distance the larger gauge wire you need.

Does both of these alternators have a internal regulator or do they need a external regulator? Just asking because my truck model uses an external regulator.

[Pro Performance]

They have an internal regulator.

[Jayschevy]

Originally Posted by Pro Performance

They have an internal regulator.

Do you have any with that use external regulation? If my current alt uses an external regulator how will I make the one with the internal regulator work?

[Pro Performance]

The 1-wire alternators are simpler for wiring. You just run 1-wire from the alternator to the starter post. This is considering you have your positive line off the battery going directly to the starter, which in most cases, it will. This is how it will charge the battery (through the starter post). It just has the one wire off the back, as the charging wire.

This is from the Powermaster site:
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.

[Jayschevy]

Looks like the 100A alt will handle what I have but I found someone selling a 140A alt at a great price way lower than the 100A one. My question is if I get the 140A alt, will the excess amps that I do not use hurt my electrical system?

[Pro Performance]

No, the higher amperage will not hurt it.

[Jayschevy]

Originally Posted by Pro Performance

No, the higher amperage will not hurt it.

Thanks,