So had teh alt. tested, and tested fine, battery is fine. Belt is fine. sheck all connections all are tight and clean. grrrrrrr.

 

WELCOME TO MY WORLD !!!!!!!!!! I posted something a few weeks ago about this very same thing........I am going to be doing some more hunting to see if I can find the problem......let me know if you find it first...lol

 

Someone mentioned about a control switch that send a message to the cmputer that AC is on, and to ramp up the RPMs to compensate. I have noticed that the RPMs do not go up at all at idle when I turn the AC on, is that supposed to happen, and if so what do I need to check to make sure is working, or what needs replaced.

Thanks for all the help

 

On 99's on up its the Idle Air Control valve that helps maintain idle under loads. Not sure on your 97, Chris would know for sure. On mine its a pindle that either lets in more air or chokes it like on cold start ups. I know its not cold out right now, but how does it start up cold?

 

It has never had a problem starting up cold or hot. I do love that about this truck, always starts.

 

Hmmm well try adding another positive cable from the battery straight to the alternator. I did this and it helped alot since I have big electric fans. Voltage comes right back up to where its supposed to be. The factory puts like 10 gauge wire. Upgrade it to at least 4.

 

Thanks for the props Ruffneck....I think it is in the user interface...i.e. control panel deal...im still working on mine to get it figured out....kinda hard when its so HOT out.....lol

 

Well I have not replaced both the cable from battery to fuse box, and now cable with an in line fuse from battery to alternator. Seems to have helped so far. Volts are holding up with AC on. Though when I stopped and was at idle with lights and AC on Volts did drop until I upped the RPMs again and that upped the volts. But while running the truck with the AC on it seems to keep the volts up, though it was only like 60 degrees here today so we will see if it still holds up when it gets hot.

I am still thinking that it might have something to do with the RPMs not going up when AC is on. More work to be done I guess.

 

SO been runnin her hard the past few week, hunting and camping. Here are the results after replacing cables.

Voltage is holding steady while running with AC on. The only time it starts to drop is when I am stopped at a light with the AC on and Holding down the break. RPM's are about 500-600. I rev it up a bit and volts go back to normal.

Now the AC does not seem to get very cold, it blows cool, not cold like it used too.

 

How noticeable is it from a dead stop idle in traffic to when on the go at 45 mph and up? Does it feel colder when rolling?