Upgrading To High Output Alternator

Installing a high output alternator with large 2 gauge wires to transfer the Amps to the battery. We have to install this with all the upgrades we did to the jeep like the 1800 watt stereo, 9,500 lbs winch, high-powered lights, and AC. This was just more than the stock alternator bear. In fact, a couple of times the load was so great the jeep stalled, not really something you want to happen. The upgraded alternator was needed, not only for battery life, but it will also keep you on the road instead of looking for jumper cables.

Picking The Right High Output Alternator

It is that hard to pick out the right high amp alternator to meet the load of all the goodies you installed in your ride. You don’t have to add up the applications’ amps using the juice, just the juice suckers you added. Start adding with 10% to 15% of the stock alternator Amps, it should be a good baseline to start from. Most factory alternators have a 10% to 15% power reserve, then just keep adding from there.

Our stock alternator in our jeep made 90 Amps new high output alternator makes 120 amps. So with the 10% to 15% reserve of the 90 Amp alternator, this would give us around 9 to 13 Amps to play with. Now adding in the 120 amp alternators 30 amps more than the factory alternator, we have 39 to 42 amps in reserve. While this is not enough to run the winch non-stop, there is a reserve in the battery to cover this, plus the added Amps would keep up better. We still have to watch it when winching, with a line pull of 9,500 lbs, at max weight the winch can consume 482 Amps. 

We didn’t get an alternator that would cover the max power consumption, we got this to keep up with normal usage, so don’t overspend on your alternator. With the 1800 watt stereo and lights cruising at 2,000 RPM, there is plenty of power to run this. Stereos may have spikes of power usage, but this is only when the bass is thumping, yet at RPM the battery voltage stays above 12.7 volts. Your battery charges with volts above 12.7, if you are dropping below this for long periods of time, you need more power. If you overtax your battery long enough, you may need a new battery or at minimum a jump start.

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What You Need To Install A High Amp Alternator

The install of an alternator is not hard, but there are a few tools you will need that you may not have. The only thing the most will need is a lug crimping tool and some heavy cable cutters. The heavy gauge cable is hard to cut and you aren’t going to get the cheap wire crimper to crimp the terminal lugs. When you’re ready to jump in most of the other tools are pretty standard, unless you have one of those fancy cars, you may be standing on your head trying to get to things.

Here is the list of all the tools we used to install our 120 Amp alternator. It May have gone a little big on the cable size, but we plan to replace the 4 gauge wire running to our amps.

Parts And Tools

• AWG Battery Cable Lug Crimping Tool 8-1/0 with Cable Cutter: https://amzn.to/3A78QSf
• AWG Copper Cable Lug Terminal with Heat Shrink Tubing: https://amzn.to/3idsqps
• CARTMAN Heavy Duty Jump Cable (2Gauge x 20Feet): https://amzn.to/3C2vHQG
• PA Performance Alternator 120 Amp: https://www.extremeterrain.com/paperf…
• Digital Multimeter: https://amzn.to/2THTsMk
• Milwaukee 18-Volt Drill and Impact Driver Kit: https://amzn.to/366BwxM
• Husky Mechanics Tool Set: https://amzn.to/3kuGUzD

Testing The Alternator Voltage

When the job is done it is fairly easy to test to make sure you have the Amps needed to run all your cool toys. Make sure you have a  multimeter for this part, I have a link above, sorry it is not to mine, mine is old, can’t buy it anymore. Then with the engine running get a baseline, it should read 14 volts or a little more. Then crank up all your toys, not the winch, and check to see if your power is staying above 12.7 volts, too easy right. If you have a winch, don’t use it as part of your test, it draws a ton of Amps!

Big Car Battery Cables Cheap

Now doing this project we know you want to save a little money, the alternate is expensive, and heavy-gauge cable ain’t cheap, or is it. We have found that you can almost spend half the money buying the gauge wire you need in the form of jumper camps. Don’t make sense, but jumper cable companies work really hard to keep their product cheap, they buy in bulk and you can reap the reward.

Jump To Video Topic:

• 00:00 Install High Output Alternator And 2 Gauge Wire
• 02:05 Tools Needed To Install Alternator And Heavy Gauge Wire
• 04:03 How To Remove An Alternator From A Jeep Wrangler
• 09:51 How To Car Create Amp And Alternator Wires On the Cheap
• 14:04 How To Install And Wire A High Output Alternator
• 16:47 How To Install The Engine Accessory Belt On A Jeep Wrangler
• 18:07 How To Test A Alternator With A multimeter
• 27:49 How To Load Test Alternator Using Multimeter
• 29:26 After Install Of Alternator And Future Projects
• 33:06 Install High Output Alternator And 2 Gauge Wire Bloopers And Outtakes