Heating and Cooling - Heater Box Removal

The next thing to do is to remove the heater core. Generally, this tends to be a big pain. You see, removing the heater core involves crawling under the dashboard, usually half upside-down, with very littler room to maneuver, while unfastening nuts and bolts in very tight and hard to reach places. Being a contortionist is not a requirement, but it is very helpful.

On the GTV, the center console must be removed before reaching the heater core. Although this is not difficult, it adds to the amount of work needed to be done. The console contains switches for actuating the wipers, heater fan, and fog lights, as well as a cigarrette lighter. These have wiring that must be disconnected and labeled, making things a bit slower.

Plus, the shift lever sticks right through the middle of the console. Again, adding to the amount of work required.

So, to start, one removes the shifter knob. On this car, the knob is a simple slip-on knob. One then removes a few screws holding the center console in place. This allows the console to be moved around, providing access to the wiring underneath the console itself.

During this whole process, I jiggled the cigarrette lighter and the various switches, just to figure out how to proceed. To my surprise, smoke starting coming out from around the lighter wiring. Holy cow! I pretty much panicked - images of the car burning down my house flashed through my mind. After fumbling for the hood lever, finally finding it and popping the hood, then looking for an unfindable 10mm wrench (is that the right size for the battery terminals?), and realizing this was taking way too much time, I figured I'd try to disconnect the wiring from the lighter itself. With the heating element glowing red, I reached in (half expecting to burn my fingers,) found the wires, and disconnected the lighter plug. Smoke streamed for a few more seconds ("what else is burning?") but then it faded and stopped altogether.

Moral of the story: always disconnect the battery when working with the car!

So, I proceeded to disconnect the battery terminal, and caught my breath. Talk about dodging a potential bullet. This is a lesson that I keep forgetting, and keeps biting me in the butt!

I then detached the wiper, heater, and fog lamp switches from the console. This allowed me to keep everything connected (and functional) while freeing up the center console itself. I also removed the heater temperature control levers and cover plates, and pulled the console out of the way.

At this point, the shift lever sits by itself, covered by two rubber boot. One of the rubber boots is supposed to cover the transmission tunnel, while the other one rests above it. In my car, they were flipped - the lower boot sat on top of the top boot! Removing the boots just involves pulling them out of the shift lever.

On closer inspection, both boots were torn. The bottom one (which should have been on top) was covered in tranny fluid (which explains some of the odors inside the car.) These things will need to be thrown out and replaced.

Once all this is removed, one can tackle the heater box itself.

One starts by removing the two air ducts connecting the heater box to the defrost vents. Each air duct is attached to the heater box by two nuts. Removing them was trivial. So far, so good.














The next thing is to disconnect the heater box from the electrical wiring. Not a big deal, but it requires labeling the wires to make sure we can connect them correctly again.

Next, one disconnects the coolant hoses from the heater box itself. I had already bypassed them, so they were mostly empty, but a bit of coolant dripped from them, nonetheless. These will be replaced with fresh hoses when putting everything back together again.



Next, one needs to unfasten the four nuts that hold the heater box in place. These nuts fasten around four studs connected to the top inside of the dashboard. Needless to say, these things are buried deep within wiring, ducts, and other parts under the dash.

To gain better access, I found it useful to remove the heater valve. After removing the heater valve, access to the two studs on the driver side was tricky, but with some patience, the nuts came out OK.

The two studs on the passenger side were a bit more accessible, but still, unfastening them was slow, patient work.


Once the mounting nuts are removed, the box can be jiggled out of place. However, there is barely enough clearance to pull the box out from under the dashboard. I eventually removed the bottom part of the heater box (the actual heater fan, as it turned out.) This allowed me to remove the box in pieces. This worked OK for now, but in all honesty, I am not sure how I'll put this all together back in place.

Overall, the box looks old and a bit rusty, but very rebuildable. The plastic parts need a good cleaning, but there is no apparent damage to it. The flapper doors (which route air to the floor, or up to the defroster vents) are rusty, but the rubber edge trim on them feels flexible and without any cracks or damage. The box needs cleanup and maybe some paint, but overall, it looks in very good shape.

Another surprise, however: the fan is actually a six-bladed fan. For my model year, the fan should have been a cylindrical "squirrel box" fan. I am not sure how the wrong fan type got in there, or to which car it belongs. It looks like a fan from an older vintage GTV, but I do not know for sure.

After all this, I bagged and labeled all the parts, and put everything away. The car is still driveable, although the transmission boots are missing, allowing noise and air to come through the transmission tunnel.

Next up: Things to buy, parts to repair.

Heating and Cooling - Heater Bypass

So, first, I figured I'd bypass the heater system in order to keep the car running without having coolant sprayed all over my feet. This buys me time to then remove the heater system, restore it, and replace it at a nice, leisurely pace.














First, I got a 10-foot length of heater hose from International Auto Parts. At $2.95 per foot plus shipping/handling, this can be a bit of a pricey option, but I figured I'd get something that works with the car. The ID is 13mm, so looking back, I figure I could source this locally and save on shipping.

The heater core is bypassed by disconnecting it at two places:
1. At the top of the engine, towards the back
2. At the water pump.















In order to avoid spills, I emptied the coolant from the engine. Raise the car high enough to fit a clean 5-gallon paint bucket under the radiator drain spout, open the drain spout, and wait. To hurry things, open the radiator cap.

Once the engine is mostly empty, close the drain spout, then open the two bleeder screws - one on the water pump, the other at the top of the engine (near the thermostat.)

Then, disconnect the coolant hoses at the two spots - at the top/rear of the engine, and at the water pump. Then connect these two places directly with 3" length of coolant hose. Make sure to route the hose away from any moving parts. Since hot coolant will flow through this hose, make sure to keep it away from anything that does not like heat.

Tighten all the various hose clamps, and refill the cooling system. As you refill the cooling system, keep the air bleed screws open until coolant starts seeping out, then replace and tighten.

That's it - it is really that simple.

Test driving the car verified that the coolant ceased to leak inside the car. Good thing. The flip side is that the car gets awfully cold at night, and with winter approaching, this becomes a major issue. But I suspect the car will be parked for most of the winter anyways, and so I will not worry too much about this yet.

Next up: removing the heater core; a few surprises.

Heating and Cooling - Intro

Heating and cooling - part 1.

So, during one of my drives around town, I noticed a bit of water around my driving foot. Not to worry - it was raining, and I thought it was probably a minor rain-related leak. Upon further inspection when I got home, I realized this was not plain water, but actual engine coolant.

Engine coolant leaks inside the car are usually not a good thing.

You see, heater systems inside most cars work by circulating hot engine coolant inside a small radiator (a.k.a. heater core) inside the car itself. A fan blows air through it (heating the air), and then to the rest of the car. For the most part, this is a fairly straightforward thing to do, but after many years, heater cores will corrode and spring leaks. On occasion, the valve controlling the flow of hot coolant onto the core will also fail, also springing leaks. Plus, you have all these rubber hoses getting coolant to and from the heater core, and these tend to fail over time.

To address this, the only thing to do is to remove any leaky parts and replace and/or rebuild them.

The two most common failure points on GTVs such as mine are the heater core itself and the heater valve. The heater valve can be sourced fairly easily at Centerline and/or International Auto Parts. It costs about $40-$50, and replacing it is straightforward.

Dealing with the heater core is a bit more involved. First, removing it from the car involves removing the complete case around the heater core itself (which contains the blower fan and other related parts.) Once this is done, rebuilding the core requires specialized expertise, and about $150-$200 worth of repairs. Then there's the matter of putting it all together and making sure it all works.

Sigh...

On the plus side, now I know what Alfa my winter project would be.

I figured I'd address this problem in two parts:
1. bypass the heater system. This is very straight forward - one bypasses the heater system from the cooling circuit. This allows me to drive the car, but alas, the heater becomes useless.

2. repair the heater system itself. Basically, disassemble the whole thing, figure out what's broken and repair it. While at it, I will replace the associated rubber hoses and any wiring that seems worn or about to fail.

Over the next few posts, I'll describe my adventures doing this. I suspect this will take a few months, as the holidays are here and my free time will be somewhat limited. But if you are curious about this kind of work, here is an excellent Alfa BB thread explaining this whole repair:

http://www.alfabb.com/bb/forums/car-restoration/3922-heater-box-rebuild.html


Next: Heating and cooling - bypassing the heater.