2000 Jimmy Instrument Cluster and Heating and AC

First I have an issue where I will be driving down the road and my speedometer will get stuck and be off for a while along with the rpm meter. I have no idea what is causing this. Also my heating and ac unit is blowing out cold air the entire time and won't give me heat when I change the direction of the flow to the defrost it still blows out of the front vents the entire time. I can turn the power of the blower up and it still works just no heat and no control of direction.

Lack of heat can be caused by many things-- number one is laow raditor coolant-- have you been having to add coolant?

Do you have manual temp control (knob with blue and red) or automatic (digital readout) - in either case an electric actuator controls the temp door- which may be inop or stripped...yo should be able to see it by removing glove box.

The air flow direction is controlled by vacuum actuators- does your vacuum line underhood have breaks, cracks, unplugged?

Brookville Oh is less than 20 miles from me.....

I have a manual temp control, it actually has temps on it and you turn the dial to them. What exactly would I be looking for when i remove the glove box? I will check the tubes in the morning kinda late to do that now. Do you have any idea on the speedometer and rpm gauge sticking and working again? Thanks

Behind the glove box, you look for and electric actuator motor- it should rotate back and orth as you dial temp knob from cold to hot and back to cold?

Does it rotate freely? Is it moving the door?- check this by unscrewing actuator mounts and checking temp door movement.

RPM and Speed may be a factor of poor plug in connections of instrument cluster-- remove instrument cluster and reseat connector plug several times- see if it helps..

I did notice that the antifreeze had rust in it so I am going to flush the coolant out on Friday and put new in maybe that will solve my heat issue.

Today my tac worked fine but my speedometer was off by anywhere from 5-10 and got stuck multiple times thank god for my android phone with a speedo on it.

I'd flush through the heater core seperately- and see how it flows, and what comes out.

How exactly would I flush the heater coil out.

Uhook heater hoses at engine end of hoses- then plumb in a garden hose- and flush both directions and watch what comes out.

But, before you do this- see if both heater hoses are warm, hot, or cool after engine is warmed up-- also notice engine temp on gauge, is it up to normal temp- say 180-200 range?