Idle problem with A/C running

[maceslin]

I have an 02 Explorer with 210K miles, 4.0 engine

When I have the A/C or defroster running and sitting at idle I noticed RPM dropping to about 450 when compressor kicked in. Tested IAC with results of 10.4 ohms which I believe is within specs. Just this past weekend with defoster running I noticed that RPM is dropping when running at 2000 RPM when compresor cycles (not sure if this was occuring before)

Engine seems to be running rough all the time, nothing noticeable on tach or when I hook up my computer but you just kind of feel it in the seat of your pants if you know what I mean.

Not sure if the two issues are related

Any sugestions on what to check to smooth out RPM with AC/deforser running? I hope it is not the PCM

Thanks for suggestions

Dave

 

[O.Madsen]

I experienced the same last week.. Idle got very low when applying various electric things. But especially the A/C. Measured the output from the alternator which was fine. Then i bought a new battery. Just a normal one within ford specs. It fixed the problem.

So maybe your battery is dying like mine was, if it is fairly old? Symptoms are spot on..

Ole

 

[maceslin]

Last night I changed the plugs and wires thinking that was the problem as they had about 100K on them. Gap was .06 while specs is .054

Did not fix the problem, have not checked the battey voltage but did not come up as red flag when I hooked up my computer. Battery not that old but will specifically check tonight

Not sure where to check next