Problem with AC/Idle

[zann20]

Hey guys I am in need of assistance, My truck has had a problem idling with the ac or defrost on and i have no idea why. The truck idles fine when ac is off but when the ac/defrost is on then the rpms fluctuate from 1000 to about 500 until i start to accelerate again. does anyone have any idea as to what the problem could be? also I am fairly new to working on cars so detailed steps would be appreciated. Thank you.

 

[kimcrwbr1]

Is the motor fuel injected? Maybe pull you IAC and clean it good both the valve and the inside of the throttle body, Open the throttle butterfly and clean good around the butterfly and venturi. It is easier to clean it if you pull the throttle body but allways install a new TB gasket. The computer controls engine idle it wouldnt hurt to clean the MAF senser with rubbing alcohol or electrical cleaner, do not use solvent. The TB you can clean with carb cleaner!

 

[kimcrwbr1]

IAC idle air control!

 

[Rearanger]

If your idle operates normally without A/C I think the problem might be with the A/C and not the IAC.

Check your compressor belt first to make sure it's tight. Might also be a problem with compressor clutch or even high/low pressure switch.

Are you getting good steady cold air? How old is the truck?

Since you don't seem to have many DIY skills it will be difficult to troubleshoot on your own.