My son disconnected the heater hoses from the heater core on his 20000 Xterra 3.3L went out of town for a few days and now does not remember which hose goes to which connection on the heater core all he has is a Haynes manual and it does not show or describe the connection. There appears to be a long hose and a shorter hose could someone be so helpful and tell me does the shorter hose connect to the upper or the lower connection of the heater core. Thanks in advance for your help I appreciate it.

If you feel back on the hoses, they go through a black clip/holder. The one on the top of the holder goes on the top hose. The one below on the bottom. They'll almost fall into place (or should). But really, it doesn't matter much as the heat is controlled by the mode doors. There's no internal 'one-direction' valve or the like on these.

Cyclemut thanks for your reply. He had decided to start replacing all his rubber hoses as he had time. He was going to replace the heater hoses so he also removed the clip/holder so I do not have that as a reference. But if I understand what you have said it does not matter which hose is connected to which inlet on the heater core if so then it will be however the hoses fit the best is that correct? Thanks again very much for your help I appreciate it.

That is correct. But, I just went out and checked under the hood of the wife's X and they were hooked up like this:

The back of the engine, where both hoses come out from, the upper hose goes to the upper heater core connector. The bottom one, goes to the bottom.

So yeah, they can go on either way, but that's how they're properly hooked up.

Glad to have you aboard rjac! Stick around, there's a bunch of us out here. Several Texas folks as well.

Longhorns fan?

Cyclemut thanks again for your time and trouble. Its all hooked up. Thanks for the welcome words. If you notice we were registered in 2003 but mostly lurk and dont post alot We have found a multitude of information on this forum. The forum is alot like GOD you only call when your in deep trouble. Yes we are Longhorn fans (that is inbred you can be deported if your not)also a Dallas Cowboys fan just not a fan of the owner, president and general manager Jerra(the jerk) Jones.

Yeah, we're Longhorns fans as well. Wife went to UT in Austin. After we were married, I had to go through a blood-letting process to be inducted or we couldn't stay married. Something about a Texas law. I dunno.

Now that I see it, you did register way back when. That there is some lurking power!