HVAC heater hoses location and part numbers.

There are several coolant hoses on the driver's side with a couple going down to the exhaust heat recirculation system behind the catalytic converters.

If you just have coolant on the back passenger side it may be the coolant reservoir releasing pressure. Usually the engine is overheating and the coolant releases from under the reservoir cap.



Often the engine water pump may be failing or perhaps a head gasket failure.

There is also a big radiator hose and a small coolant hose on the front passenger side of the engine along with the reservoir on the passenger fender.

If it is losing coolant in any way, air can keep the heater from working. There are also air mixing servos inside the blower / ac / heater assembly inside the dash. Sometimes one of the servo doors fails and blocks off the heater core. Not likely in this case.

If gasket sealer was used the heater core could be blocked. This in itself would not cause coolant release but could reduce heater output.

Overall, find and fix the coolant leak or overheating release. Then fill with coolant and check the cabin heat.

 

How many miles on the car?

 

Is that a typo? I have never seen someone with that many miles on a Gen 3.