Re: alfa-digest V8 #273 - Alfa Spider Heater Fan

[AlfaNeely@domain.elided]

In a message dated 12/06/2001 4:14:52 PM Central Standard Time, 
owner-alfa-digest@domain.elided writes:


> Date: Thu, 6 Dec 2001 17:41:48 -0800
> From: "john mccall" <jmccall001@domain.elided>
> Subject: Winter Help
> 
> Have a 78 Spider.  Installed new radio with no provblem except the heater
> blower fan quit.  When I checked the rocker switch, it fell apart.  The 
> Haynes
> Manual I have doesn't mention any how to on this.  I suspect the motor 
> burned
> out since a new switch. was installed.  Tips on trouble shooting and 
> replacing
> the fan so I can enjoy this car in winter?
> 
> Thanks,  John McCall
> 
> 

       This was all covered on the Digest a few months ago.  However, here 
goes again.
    Changing the heater fan in an Alfa spider is a pain.  If the car is air 
conditioned, the following will apply only to the extent that you can get 
around the air conditioning ducts.  The knee bolsters on later model spiders 
further complicate the matter.
    The last heater fan I changed was on my 82 Spider Veloce, which is not 
air conditioned.  When I built the car, I also left off the sides of the 
console.  I had intended to install a radio, but have found the engine sounds 
sufficient music.  If your Alfa has a console remove it, or at least the 
sides.
    The heater sits on top of the transmission tunnel.  The top bolts to the 
bottom of the air plenum that also holds the windshield wipers.  There are 
two drains, one on each end of the plenum; however, the other drain is into 
the heater itself.  It is rather like a large funnel on top of the heater.  
The problem is the fan is at the bottom of the heater box where all the water 
ends up.  It is a wonder the fan lasts any time at all.
    The black case of the heater is held together with spring clips - two you 
can get to and three on the firewall side.  You can get the clips off and 
remove the bottom of the heater box.  You can also work the bottom of the 
heater box back in place later and you could probably wedge something under 
the bottom to hold it in place.  However, you will not be able to get the 
clips back on to properly reassemble the heater without removing the whole 
thing from the car.
    Before removing the heater, test the fan.  Three wires come out of the 
heater box.  Beside the foot feed is a terminal block.  Run a jumper to each 
of the two wires on the block.  One is high speed, one is low.  If the heater 
switch is bad, bypassing it with a jumper should tell you that.
    First remove the defroster ducts from each side of the heater.  Leave the 
ducts in place and remove only the plastic ends.
    Two heater hoses come though the firewall.  One hose is on the passenger 
side.  The other and the heater on / off valve are located above the driver's 
right foot.  You have to remove both heater hoses.  Drain the radiator before 
you remove the hoses.  Also remove the cables connected to the water control 
valve and to the lever for the duct on the front of the heater.
    I find that putting your butt in the seat, your legs over the back of the 
seat and your head in the foot well is the best way.  At that point there is 
no room for your arms and you are going to drop a wrench or nut and washer 
and you are going to have to crawl out of the car to fetch them.
    There are four 5 mm bolts (8 mm socket) holding the heater at the top, 
two on each side.  The flange on the heater is slotted, so you only have to 
remove them completely on one side, probably the passenger side.  Since the 
bolts are so small and surely rusted, you are probably going to break off at 
least two of the four.
    With the defroster ducts, the two heater hoses, the control cables and 
the bolts at the top removed, the heater can be worked out.  There is not a 
lot of room to work, but it can be done.
    With the heater out, you can disassemble it.  The top is held on by the 
five spring clips mentioned earlier.  Note the way the linkage for the 
defroster flaps fits and how the defroster flaps move.  You will need to get 
everything back in correct orientation upon reassembly.  The bottom of the 
heater where the fan is located is held on by bolts. You cannot access the 
screw heads until you remove the clips and the top half.  You may be able to 
get the nuts off without holding the bolt with a Phillips screwdriver.
    The fan is held in place with two rubber pads.  These are forced by a 
detent to hold the fan in place. To remove it, pull.  And of course you have 
to remove the wires where they fit through a grommet.
    I have had occasional success getting the fan motor to run.  I have used 
WD-40 to lubricate the fan bearings.  I have cleaned up the commutator and 
brushes.  I have changed fan blades from motor to motor.  I have robbed 
motors from Alfa parts cars when none of the above worked.  There was a NOS 
fan for sale at convention last summer.  I should have bought it.
    While you have the heater core out, you could take it to a radiator shop. 
 They can clean and pressure test it.  Or you can just blow though it and 
hope it is not ready to spring a leak.
    There are various bits of foam rubber sealing the heater box.  These foam 
will have hardened and will crumble to the touch.  Buy some appropriate foam 
insulation at your local hardware store.  The kind with sticky backing will 
be needed at the top where the heater bolts to the body.
    For the bolts you broke off, I have drilled out the remaining portion.  I 
put in larger 6 mm bolts from the top side and tack welded the heads to the 
sheet metal.  This is hidden from view by the cowl vent so no body work is 
required.  A bit of rust preventative paint on the top would be good.
    Reassembly of the heater, as they say, is the reverse of the above.  
Well, that may not be entirely correct.
    You will discover four square bits of metal laying around where you took 
the heater apart.  The four little square metal bits have a hole in the 
middle.  These are the nuts for the defroster duct bolts.  I am sure you will 
not notice them fall out nor will you notice where they came from.  They fit 
back into slots in the middle of the case.  They are held in place with the 
upper half of the heater, which is held in place in its turn by the five 
spring clips.  The two bolts that attach the plastic defroster ducts screw 
into them.

Ciao,
Russ Neely
Oklahoma City

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