floatingDust

My heater does not work, it just blows cold air in all different modes. I've tried turning a/c on and off, changing the temperature setting up and down in each mode, and whatever I try to do, the difference between max hi and low temp is maybe like 5 degrees different. A/C works just fine though, it has no problem blasting cold air.

Any ideas on what I can do to fix this, or where to start with troubleshooting? Thanks

floatingDust

I tried the holding the off button and pressing the rear window defroster 5 times diagnkstic thing, and i didnt get any code, everything just came on solid on my display, solid 88 and all the other hvac indications, not sure what that means, but my guess is its not an electrical problem or something with the climate control system. Any help would be appreciated.

vaprea

Check your coolant level, make sure its nice and full.

737 Jock

If the diagnostic showed no electrical control problems then the issue is mechanical. Hot coolant is not entering your heater core.

As posted above check your coolant level first. However low coolant may not be the cause, as coolant comes directly off the cylinder head and turbo straight to the heater core. If coolant was so low as to not enter the heater, then there would be major engine damage.

It is more likely that the heater inlet valve is not working or the heater valve cable is jammed/out of adjustment. The heater inlet valve meters the hot cylinder head/turbo coolant into the heater core. It is driven by a mechanical cable that runs from the air mix controller (under the dash) to the heater valve (under the hood).

Try having the heater valve cable checked and adjusted. If that doesn't work, the heater valve may need replaced.

floatingDust

Thanks I will definitely check it out. I took a quick look under the hood last night to try and find the heater inlet valve, and didn't see it in the dark, but I will take a look again.

737 Jock

It's tough to see. The heater valve is on the hose that comes off the cylinder head water outlet and runs to the firewall. It is just below and to the right of the brake booster reservoir.

The cable is on the front of it, and you should be able to see it move if you have someone run the temp up and down from inside. Do that with the engine OFF of course.

Renegade

I have the same issue. Was this ever resolved?

Poveiro

I had this problem the coolant was low and the heater was sending cold air, once in a wile some hot but most of the times cold only. No damage to the engine as I noticed right away as I was coming from the nord, later to find that was a small leak using a UV addictive to the coolant was a tube coming out of the thermostat corroded. ([b=left]Pipe, Heater[/b]19510-RWC-A00)

Max_NJ

Update on My issue. Had a service appointment last week and they said the freon was low but couldn't find the leak. System was recharged and was blowing really cold air for a few days on both sides, working as it should. I've noticed it not working as well now though so it's obviously still leaking. They added dye to the freon so they could find the leak. I'm going to wait until it gets a little worse to bring it back.