Re: Sanden compressor clutch and other things

Posted by HH56 On 2013/10/21 12:36:43

The large battery is charged all the time as per usual but the small one can only be charged when the clutch is not engaged. I am hoping the clutch cycle off or rest time will be enough to keep it at a reasonable level while AC is running. The small battery can fall quite a bit before the voltage it contributes is too low to do much. If the reports of those running on 6v is correct, it could fall to 0 volts and not be missed. Of course, that doesn't do the battery much good so we'll see how it works out or how long it lasts. When the AC is off or when car is off and parked then it should recharge back to the same potential as the main battery minus a few hundred millivolts because of the charge current limit resistor.

The battery is just a small sealed rechargeable 12 ah lead acid unit similar to McMasters 7448K34. I picked mine up locally. There are larger capacity units in roughly the same size package and if needed, can go with one of those or even parallel this one. Will try small cheap and simple first.

I am planning to install it on the firewall where I have the mockup shown. In doing so I added another relay in the module to disconnect AC when ign is off. That signal plus the starter signal can probably be grabbed off the starter switch on carb -- but will investigate that farther. Those two wires plus the run to compressor can be in a single loom. Another two wires will need to go into the passenger compt for the AC power and clutch signal so another loom thru firewall in one of the existing grommets. The power to the entire assy will come off the starter solenoid terminal with ground wherever convenient. Anyway, that's todays plan. It can change tomorrow.

Debating on the alternator but probably will try keeping the generator for awhile and see how it does. Downside to this experiment is it will be some time before my car is anywhere close to being ready to test. Until that happens I can't say with certainty something overlooked or negative will not show up.