Heater door rot

Heater Blend Door Rot

I've repaired several New Beetle heater blend doors with obvious success.

Last week the AC went out in my 03 Jetta. Today, I had to drive it to run several errands. Wow, the heat was horrible.

Anyway, I noticed bits of sponge coming out the center vent. So, no doubt it needs the blend door repairs. And, without the AC I could tell that there is a we bit of heater out-put.

So, here's my question, has anyone installed a coolant shut-off valve to the heater?......... and, maybe to include a push-pull control knob under the dash to operate it?

When I put the ALH in my Vanagon, all those hoses were removed, including the EGR cooler plumbing. The only "continuous" circulation is via the expansion tank and oil cooler/warmer. The coolant to the heater core has a shut-off valve. I've never experienced an over-heating issue with the set-up.

The primary reason I don't do a blend door fix on my Jetta is that I do not have the radio code ....... and, the radio and CD player work fine!

Thoughts?

You can easily get the radio code, call a dealer with the radio's serial number and VIN and they can look it up for you. Some dealer's might say there's a charge for that, if so just call another dealer and try again.

The only time I've ever needed to enter the radio code is if I swapped in a different radio. The radio seems to remember the car it was installed in and only demand the radio code if it's installed in a different car.

Yep -- provided the radio is in the same car it originally came from the factory in the ECU and radio should talk and it will re-authenticate itself. I had the same worries years ago and was told this would be the case, and it apparently is -- I've had the power off (battery out) for well more than a full day and never needed the code.

Most recently I changed out the battery in the car without a "tender" and, again, no problem.

The Radio and ECU don't always speak the same language. The Radio (original) in my 2000 Jetta went into Limp Mode when I was cleaning battery posts and cable ends. I had misplaced the code long ago. Almost to the day, a year later, the Radio began working properly.

My '02 has never asked for the radio code when I've replaced the battery or had it disconnected, so I'd wager the 03 is the same.

You should not need to enter a radio code on any CAN bus car.

There is supposed to be coolant flowing through that circuit of the engine always.

The temp blend door forces air up and past the heater core. If it gets full of holes, you will have no heat... the A/C (which ALWAYS has air flowing through the evaporator core) will work just fine. So if your A/C "quit", it isn't the temp door's fault.

The AC did quit, but the blend door foam has been blowing out the vents for some time. So, my intent was to deal with the entire set of issues as a project. But, if I could just valve off the heater circulation, I'd not worry about the blend doors.

I'm assuming the design of the heater box, etc., for the A4 Jetta and New Beetle is the same. If so the bottom blend door either diverts air up and away from the heater core or allows it to go straight thru over to the heater core, depending on the setting.

As for the coolant circulation, I understand the routing, but is it necessary? I see it being necessary to cool the exhaust for the EGR. As I said in the opening post, I eliminated all that plumbing and the plumbing for the heater uses the OE coolant flow valve for the heater core and never an over heating incident.

Well, this is something I plan to get into toward the end of Sept. We've leaving a week from tomorrow on at least a two week road trip to the northeast, with others. So, no time at the moment to be working on the Jetta.