My honda oddyssey 2000 EX has problem in rear heating system ?

You have a Blend Door Actuator that is not working as it should. They open and close to direct hot or cool air.

Dear An,
The vents that direct the air to certain areas of the cars or trucks are plastic, and over time, will warp, or stick, or break.
This applies to all cars & trucks.
A good rule of thumb is, 10 years of working correctly.
If you choose to fix this, or have it fixed, start with the under dash unit, in a ********* plastic box.
Open that up and see if everything is working properly.
Then go to the tubes or pipes that send the heat or cool to the rear.
This may requires taking the seats and the carpets out to access those tubes or pipes.
Understand a dealer may charge you many hundreds of dollars, or even a few thousand to do this, because it is "labor intensive".
God bless your efforts.

This model has a rear heat/cold blend door actuator. Its an electric motor that moves the duct door from hot to cold. When they wear out, they're usually stuck on the last setting

THE EXPANSION VALVE IN REAR UNIT IS STUCK CLOSED WILL NEED TO BE REPLACED

I assume your talking 3rd row seating A/C, Have the same car and had same problem. Unless you use 3rd row much, unplug it ( under passenger side wheel hump pocket ) this will stop the clicking and has no effect on A/C cooling front & middle row in Florida heat. There are actually 2 plugs, do both. Not the best, but the easiest & cheapest.
Ken

It sounds like a stuck gate/flap/door. This takes some time and effort as you may need to dig into the cars Heating/AC plumbing.

Sounds like the flapper valve for the rear heater/AC core is not doing its job to send the air through the AC core when called for.

Another clue of this is the fact that the air is coming out on the lower vents when it should be up high fro AC.

Have someone listen back by the fan inlet in the back usually on the right while you switch between AC and heat to see if they hear any noise or change in air flow.

Worst case is that the interior panel there has to be removed to service the assembly behind it.

You need to replace the driver side temperature door control actuator. While doing this... make sure you bolt the new one in AND THEN PLUG IT IN or it will spin and not line up in the right place... then there is a series of crazy steps to fix that problem.

I have the same problem with my 2002 Durango. After accessing the rear HVAC unit you will find that there is a rear electronic actuator that operates a plastic door inside the duct system. The door switches the rear system between heat and cold. I had two broken items, the white actuator connector has a tab that broke off and the door inside the duct has broken where this connector fits inside. I am still trying to find the parts on line. I do not know what the part numbers are for these two items. Hope that helps, it seems to be a typical problem with the older durango's.

2000 Honda Odyssey the middle seat belt is broken. The seatbelt won't retract. The end of the belt does not come out but the entire seatbelt will come out of the hole.
Any suggestions?