kevofcov
Member Since: 06 Nov 2007
Location: Other end of M69
Posts: 533
  
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| Help with cab heater blower mod please |
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Hi
My car is a 56 auto hse in the best colour.
I have a Webasco timer fitted and it works great but as we all know it doesn't heat the cab, it only triggers the fuel burning heater to pre heat the engine before you get in.
I noticed a little while ago that the heater blower fan for the rear two seats receives hot coolant whilst the webasco is doing its thing. This planted the seed for an idea to heat the inside of the car before Doris gets on board first thing in the morning. This would get me many brownie points and i need them bad.
My intention was to power the rear blower using the 2nd vehicle battery through a multi pole relay (to isolate my mod from the cars Canbus electrics thingy) - all triggered by the webasco.
Bingo, it works.
However, the heat produced is only enough to make the rear two seats toast, the middle three ok but the front two certainly not worth the effort.
The logical next step is to do the same to the front heater blower instead and get the front seats toast. I think I read a thread from someone who was doing a similar project. Can anybody advise me on the following before I remove the dash with my blunt phillips-
1) Where is the front blower and is it hard to access the wiring?
2) When the car is 'asleep' will the warm air be directed into the cab when I blow it - are there any flap/valves that can foil me?
Thanks for any help
Kev
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 6th Dec 2008 3:33 pm |
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NoDo$h
Member Since: 02 May 2006
Location: Finding new and exciting ways to milk badgers.
Posts: 19689
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All the flaps shut down when the car goes to sleep and you'll need to find the bus code to defeat that. Good luck, as nobody has managed it yet I'm afraid (but don't let that stop you trying!). I know it's not considered "kind" to say no these days, but no. Just no, ok? And if it's not ok, still no.
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| 6th Dec 2008 6:26 pm |
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kevofcov
Member Since: 06 Nov 2007
Location: Other end of M69
Posts: 533
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Nodosh
thankyou for your reply.
I am afraid I will run out of talent long before I overcome the code thingies needed.
The rear blower was using 10amps anyway so I think I will end up using an aftermarket 12v ceramic (13amp) car interior heater mounted by the pedals.
Watch this space..............
Kev
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| 6th Dec 2008 8:40 pm |
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Carabraxis
Member Since: 30 Dec 2007
Location: Mansfield
Posts: 220
 
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Do we know what flaps shut?
If it only the ones to outside does that not effectivly mean that the fan would run on recirculate? Thus pushing air through the heat exchanger and into the cabin
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| 6th Dec 2008 9:11 pm |
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kevofcov
Member Since: 06 Nov 2007
Location: Other end of M69
Posts: 533
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The easiest thing may be to put 12v across the motor and see where the air goes. I'll have a fiddle later today when it gets warmer.
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| 7th Dec 2008 11:11 am |
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TazDaz
Member Since: 07 May 2007
Location: South East Essex
Posts: 2858
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kevofcov - don't think anyone's solved the interior heater but TenforCash has a solution for switching on the windscreen heater and the front seat heaters as well as the FBH. Maybe worth contacting him.
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| 7th Dec 2008 7:20 pm |
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stapldm
Member Since: 11 Sep 2006
Location: Swine Town
Posts: 2330
 
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KoC, hmmm, OK maybe that abbreviation is no good 
Ahem, KevofCov, I'm pleased to say you're trailblazing where I've wanted to go yet not had the time. Here's where my thoughts are without having been able to open up the dash yet.
To keep the amps down at the fan, I'd suggest using a dropper resistor out of the fan speed controller of a lesser car. These use a wound resistance wire, that is usually kept in the fans own airflow to keep its temperature down. I'd use a DPDT relay to switch this in though, to prevent volts being passed backwards into the D3 fan controllers PWM speed control circuit. With some extra effort you may find a make/model of car that uses PWM control built into a relay look alike, or alternatively some electronics mags have advertisers selling 10A PWM 12v motor speed controllers for ~£15. When I get around to doing this, I'll buy PWM - it's kinder on the motor at low speeds.
When it comes to the messing around with the flaps, like in humans, some care is required. I'm not sure if they're :
1) 3-wire servo (same as model aircraft type - position control is local to motor, PWM signal provided to command required position)
2) As above, but instead of 3rd wire being position input, it's a simple output based on a variable resistor mounted on the shaft - control is remote to the motor).
3) 2-wire servo (same as in cd/dvd lens position control - nightmare to control!)
4) 2-wire motor, micro-switch position detect (cam on shaft operates switches to determine set positions)
Obviously, all of these require different methods of proper control, however there can be a cheat. By applying 12v (assuming they are 12v!) to all these types, the flap may travel to 'another' position to that of its rest state.
Provisos:
This may require current limiting to prevent the motor cooking once it stalls.
Again, I'd suggest using a relay to isolate your own override from the original electronics.
Type 1) may get upset at being supplied voltage in reverse, the other types would relish it and give another possible position of the flaps.
Once the flaps are in their new position, you may find yourself getting hot 
If you find out what kind of flaps the d3 has, I'd love to know  Dr. Ian Malcolm:
"Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should."
Transgenic tomato anyone?
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| 7th Dec 2008 8:31 pm |
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beekeeper2003
Member Since: 10 Apr 2008
Location: Ripon
Posts: 17
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I know it is just a tad dearer but doesn't the Range Rover Vogue control system manage to overcome these problems ? Hopefully someone with access to the circuit diagram who also has some technical know how might manage to infigure it through or possibly it is SO different as to be impossible. Just a thought.
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| 7th Dec 2008 9:41 pm |
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kevofcov
Member Since: 06 Nov 2007
Location: Other end of M69
Posts: 533
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Just an update.
The 12v ceramic cab heater was pants and not worth the effort of removing the wrapper. I will be checking that it wasn't the battery or sumfin silly just in case.
Its my wifes car so I wont be able to look at her flaps till the weekend but I they are my last chuck of the dice.
regards
Koc
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| 10th Dec 2008 8:28 pm |
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Ent
Member Since: 12 Oct 2007
Location: In the cack
Posts: 6485
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kevofcov wrote: I wont be able to look at her flaps till the weekend but I they are my last chuck of the dice.
regards
Koc
Thats just tooooooooo easy  Club Exped trailer
Club Timed Climate
Club Flappy paddle steering wheel
Club 300bhp
Club Prospeed test pilot/lab rat
Club National Luna Stella conditioner
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| 10th Dec 2008 8:35 pm |
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kevofcov
Member Since: 06 Nov 2007
Location: Other end of M69
Posts: 533
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Sorry - but ya just gotta slip it in when you can.
Koc
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| 11th Dec 2008 9:42 am |
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