Ticking every 10 seconds, causing engine to rev in idle, and on the road??

[twilitekiller]

In my 1993 Ford Explorer I noticed this over the summer last year, and it went away during the winter. Now that it's above freezing it does it again. In idle it will rev from under 1000 rpms to about 1500-2000 every 10 seconds or so. When I looked underneath the hood the one main belt you can see...whatever it goes around at the top right shuts on and off and it's in sync with the revving. I don't have the manual and would really like to know what it causing this. Thank you in advance for your time!

 

[KobeJ05]

In my 1993 Ford Explorer I noticed this over the summer last year, and it went away during the winter. Now that it's above freezing it does it again. In idle it will rev from under 1000 rpms to about 1500-2000 every 10 seconds or so. When I looked underneath the hood the one main belt you can see...whatever it goes around at the top right shuts on and off and it's in sync with the revving. I don't have the manual and would really like to know what it causing this. Thank you in advance for your time!

your A/C if thats what your talking about.
if your a/c or defrost is on you will hear it click.

 

[twilitekiller]

I haven't recharged my A/C but it does it when the A/C is on, Heat is on, or everything is off. And would that be the cause of my RPMs to increase?

 

[KobeJ05]

could be the mass air flow sensor or map semsor. probably need to be cleaned. im sure others will reply here with ideas. welcome to the forum

 

[twilitekiller]

I guess its time to get down and dirty! I've looked over other posts with similar problems, luckily nothing too major seems to be needing fixing.