idle problem with my 96 Ram 1500

[jscheuffele]

Hey everyone, I'm pretty new to this, but I need some help. I just got a used 96 Dodge Ram 1500 V-6 manual pickup. While I drove it with the A/C off, it runs great. When I turn the A/C on, even to the lowest setting, the truck dies every time I stop or take my foot off the gas. I have changed out all of my plugs and wires and that didn't fix the problem. I thought that it might just be an idle problem, but I couldn't find the low-end idle adjustment screw for it. Does anyone have any solutions, or at least a picture of where the adjustment screw would be on this engine? Thanks for any help!

[Austin8214]

this may sound way off base but check your alternator output. You may also have a weak battery.

[jscheuffele]

I know the battery is strong, but how do I check the output of the alternator? I have a voltage meeter on it, and it checks out ok. It also starts right back up again once it dies. Thanks.

[Austin8214]

Originally Posted by jscheuffele

I know the battery is strong, but how do I check the output of the alternator? I have a voltage meeter on it, and it checks out ok. It also starts right back up again once it dies. Thanks.

You need to check it with a hand held multi meter. The one in the truck is not accurate to say the least. The alternator should be putting out 14volts to charge the battery properly. You can check this with the truck running and your ac on you should be getting 14 volts at your battery.

[scoutinkeith]

I'm not to familular with the V-6 engines, so this my not be much help,
but on the V-8 engines(5.2 and 5.9), there is an Idle Air Control(IAC) valve/actuator that sometimes gets cloged, and doesn't function properly.

again, on the V8's, when at idle, the throttle blades are compleatly closed, and the IAC is what controls the amount of air going to the engine. if it's stuck, and can't move freely, it may not be able to increase the idle enough to keep the engine running with the extra drag of the AC compressor.

[jscheuffele]

Originally Posted by scoutinkeith

I'm not to familular with the V-6 engines, so this my not be much help,
but on the V-8 engines(5.2 and 5.9), there is an Idle Air Control(IAC) valve/actuator that sometimes gets cloged, and doesn't function properly.

again, on the V8's, when at idle, the throttle blades are compleatly closed, and the IAC is what controls the amount of air going to the engine. if it's stuck, and can't move freely, it may not be able to increase the idle enough to keep the engine running with the extra drag of the AC compressor.

If there were a clogg in the IAC, would that show up on an OBD II diagnostic scan? I did one of those and it came up clean (no error codes). How else would I check to see if that were the problem? Thanks

[jscheuffele]

Originally Posted by Austin8214

You need to check it with a hand held multi meter. The one in the truck is not accurate to say the least. The alternator should be putting out 14volts to charge the battery properly. You can check this with the truck running and your ac on you should be getting 14 volts at your battery.

I checked the voltage with the A/C on and off and the readings came out to 13.65 V with it on, and 13.69 with it off. It's a little low, but is that low enough to cause the idle to drop and the truck to die?

[scoutinkeith]

Originally Posted by jscheuffele

If there were a clogg in the IAC, would that show up on an OBD II diagnostic scan? I did one of those and it came up clean (no error codes). How else would I check to see if that were the problem? Thanks

I'm not sure if it would show up or not. I kinda doubt it, since the IAC is NOT a sensor, it's just a little actuator and plunger.
as far as checking it, on the V-8 engines, the IAC is located on the back side of the Throttle Body, and can be removed by taking out two torx screws, and unplugging one electrical connection. you'll want to look for excessive buildup on the end of the plunger, as well as on the Throttle Body where the plunger seats. also, there is a little rubber O-ring that seals the IAC housing to the TB, be carefull not to drop it when you pull the IAC off.
once you have it off, just spray it, as well as the throttle body, with some carb/TB cleaner to remove any buildup, and reinstall. also, you'll want to disconnect the negative battery cable to reset the computer once you have the IAC reinstalled.

[Austin8214]

Originally Posted by jscheuffele

I checked the voltage with the A/C on and off and the readings came out to 13.65 V with it on, and 13.69 with it off. It's a little low, but is that low enough to cause the idle to drop and the truck to die?

13.6 should be fine. I would now check out the IAC as scoutinkeith suggested.

[jscheuffele]

Ok, I took off the IAC and looked inside... it looked pretty clean. I sprayed it with the cleaner and put it back together, after disconnecting and reconnecting the negative battery cable, I took it for a test run, and it did the same thing. Is there anything else that would be causing it? Thanks for your help!

[scoutinkeith]

dose the AC seem to be working correctly? my only other guess would be that the compressor isn't spinning freely enough, and bogging down the engine. however, if that were the case, I'd expect that the belt would squeel before the engine would die.

[jscheuffele]

The A/C works fine. There is a belt that squeels occasionally, but it squeels when the A/C is on and when it's off... and doesn't die right afterwards. It doesn't seem to have any direct connection to the idle problem... at least to me.

[jscheuffele]

I do have a leek in my power steering pump, that I need to fix. Could that, somehow, be the problem?

[89ltd]

The computer should compensate and bring the idle up via the iac valve when you turn the a/c on. I'll have to find a wiring diagram to see what tells the computer that the a/c is on.

[Slade901]

More than likely the ac compressor pulley is seizing up when the ac clutch engages when you turn on the AC.