Chevy & GMC Vans

Just curious and won't go into any detail but would I need to run a second alt. if I were going to run a 550 watt AC unit ? It would only be on while driving.

That A/C unit will draw around 46 amps by itself. Since you run a carb'd engine, I would think a stock 105 amp alternator would be good since you will be driving with it. If you were sitting idling for longer periods I would look at swapping in a single high amp alternator. You could also add a second battery to make sure it doesn't pull the voltage down too much.

thanks for the info. I think the 140 amp alt might be the way to go but still not sure on wire size. This electric thing is not my cup of tea or Mint Julip that is.

if you are upgrading the alternator upgrade the wires going to the battery also. there are many posts about upgraging the "BIG 3"; the power wire going from the alternator to the battery, the ground wire going from the battery to the frame, and the ground wire going from the battery to the engine block.
I would recommend this upgrade to everyone, using at least 4ga. wire. I would add wire going to the alternator from the battery and keep the stock wire connected, current will go the path of the least resistance.
one more thing I did was add a ground wire from the case of the alternator(s) to the battery's ground. this way I am not relying just on the block ground for a good ground.

Yep,,did all these a couple of years ago. Think with a 140 amp. alt I'll be ok but just not sure on wire size from battery to invertor and invertor to ac unit.

Rebel wrote:just not sure on wire size from battery to invertor and invertor to ac unit.

depending on how far back the invertor is I would say at least 4ga. (remember to add your fuse at the battery too). the a/c unit has a regular 3 pronged cord correct?

no, it's not the regular 3 prong,,it's looks more like a three prong 220 plug but fits regular 110 recepticle. Very large,,first time I've ever seen one.

Rebel wrote:no, it's not the regular 3 prong,,it's looks more like a three prong 220 plug but fits regular 110 recepticle. Very large,,first time I've ever seen one.

is it just the plug and no wires?
if so 8 ga. wires should be fine.

No, plug is attached to wires that run to AC unit.
Thanks for all the info,,really appreciate it.

The plug on the end of the A/C unit is probably one of the new arc fault interrupters. Our A/C units here at work all have them now. They have a test and reset button just like a GFCI does.

That's exactly right,,forgot about the reset button on the plug.

Just a reminder Larry,its better to have the inverter closer to the batt and run a longer A.C cord than the other way around
oh yea, take lotsa pics

Just a reminder Larry,its better to have the inverter closer to the batt and run a longer A.C cord than the other way around

Good point Keith. Thanks for the electrical help you guys. It's not one of my things for sure. I've got the plan in my head as far as fab work. Will do on the pics.
Got to lay 179 feet of shoemolding in the house and after that, think Susan may let me back in the garage.

Hey Larry,

You don't need AC you're too cool already. How you been guy? How are you feeling?

I like to run 2 guage welding ground cable for everything HD including my big three.

The fine strands and the fat diameter make it a great conductor,no matter how long the length is, make sure that you solder the ends. (use a blow torch)