home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Symposium > article composition

Reply
 
Thread Tools Display Modes
Old 01-16-2016, 12:09 PM   #1
nordmaschine
forced instruction
 
nordmaschine's Avatar
 
Join Date: Feb 2012
Location: The Balkans, BiH
Default PWM blower

The N/A 940 I have has MCC heater/AC, and the day it came it was missing blower speed control knob completely, and had a random pull pot switch besides defroster switch, acting as a on/off toggle for single (highest) speed.
I didn't have a spare 940 MCC control unit to swap in so I left it like that for a couple of years...
This winter it has been my daily driver and the sound of fan constantly sqeeling on 5 leaves a lot to be desired.

I just don't care enough to go around JY's tring to find MCC control unit, and don't find it worth those 40-ish $. Even then, it could turn out that someone was stupid and ripped blower switch apart because resistors burned out, so I'd be back to square one.


So, here is 3$ and 30 minutes solution for dead switches and burned resistors, idiotproof, I believe.


What you need is this PWM controller:
http://www.ebay.com/itm/1PC-New-PWM-...sAAOSwkNZUdDqc

(or any other, this was just cheapest one I could find on ebay at given moment)

- couple of feet of 12-ish AWG wire, preferably in red and black insulation.

- a couple of insulated spade terminals and snap on splices

- electrical insulstion tape

- ZIP TIES!


I already had hole for controller drilled here, so I left it there:


I also had ignition + from ignition switch that someone before brought to the pot switch, so I used it on Power + terminal of the controller. Wire that was leaving the pot I taped back over itself, it won't be used. I guess you don't have a pot anyway, so a snap-on splice from ignition switch works here. Or from the cigarette lighter, or whatever...

For "Power -" on the controller, I took an insulsted female spade, plugged it into ground distribution block in passenger footwell behind the ECU.

This is a good time to remove glovebox too, since it's a lot easier to fish wires around and work around motor that way...



Here are the wires that go into the fan. white-black is ground, white-red is power. I cut them (you don't hsve to, JY pigtail connector which I felt too lazy to go in the attic and find, would be great here) a coulpe inches from the connector and crimped (it the picture they were just tied together for testing) according extension wires to "Motor -" and "Motor +" terminals on the controller. Other side (that goes from the resistor pack, which you don't need any more) I've taped back over themselves...

Fix wires with zip-ties so they don't hang loosely around and put glovebox back into place and that's it - variable speed blower motor and no more resistors.
__________________
Will race for food.
- '94 965 - BMW M50B25 engine and Getrag 260 transmission - burried in the garage.
- '90 744 turbo 16 valve - d̶a̶i̶l̶y̶ ̶d̶r̶i̶v̶e̶r̶ garden decoration
Quote:
Originally Posted by Kjets On a Plane View Post
Whiteblocks
Quote:
Originally Posted by AdmiralSenn View Post
I think I might be too stupid to own a car.
nordmaschine is offline   Reply With Quote
Old 01-18-2016, 03:45 PM   #2
volvo?
Board Member
 
Join Date: Nov 2009
Location: MOLALLA OR
Default

How many amps does the heater blower pull? I would think more than 3. On my car ('90 245) it's on its own 25A circuit.
__________________
Quote:
Originally Posted by spruill242 View Post
That's the creep I'm talking about! It sneeks up on you and then you're crapping your pants.
volvo? is online now   Reply With Quote
Old 01-19-2016, 07:19 AM   #3
nordmaschine
forced instruction
 
nordmaschine's Avatar
 
Join Date: Feb 2012
Location: The Balkans, BiH
Default

I would think so too. Much more than 3A, probably. Didn't remember to measure.
However, this has been working for the past few days around 12h a day and still hasn't melted, so I guess it's okay. Let's see how long till it granades.
nordmaschine is offline   Reply With Quote
Old 01-19-2016, 07:49 AM   #4
JW240
Your current user title
 
JW240's Avatar
 
Join Date: Aug 2004
Location: The Netherlands, Europe
Default

Nice idea, have been thinking of this as well for my 240. Maybe after I fix the other issues
__________________
240 | 1991 | 302 KKm | B230F+T | Cossie T3 60/63 | M90 | Toyo R1R/Polaris
Amazon/121 | 1968 | finished 2018+?
760 | 1984 | B6284T swap | 2x13T | finished 201?

JW240 is offline   Reply With Quote
Old 01-19-2016, 03:50 PM   #5
nordmaschine
forced instruction
 
nordmaschine's Avatar
 
Join Date: Feb 2012
Location: The Balkans, BiH
Default

Till you fix that, I'll probably be able to assess whether this is going to work as a permanent fix. If not, there are tougher controllers for not much more - this one is ultra ghetto. But it survived another 12h of abuse, I'm getting confident.

Also, if I ever find enough time and will, I might pull the heater controlls out and fix this in place of stock switch, using stock knob for ultra stealth. If it ever happens, I')) take a pic or two and that should complete the "article"...
nordmaschine is offline   Reply With Quote
Old 01-25-2016, 04:07 AM   #6
Karl Buchka
Never go full retard.
 
Karl Buchka's Avatar
 
Join Date: Mar 2007
Location: Los Angeles
Default

I did some preliminary work on a project like this for 240s a few years ago. At least for a 240 you need to be aware of the AC override on the fan control, so it's not completely obvious how to implement it cleanly.
Karl Buchka is offline   Reply With Quote
Old 01-25-2016, 10:51 AM   #7
JW240
Your current user title
 
JW240's Avatar
 
Join Date: Aug 2004
Location: The Netherlands, Europe
Default

I've been thinking if an 850/v70 fan motor+blades could be swapped in with some mods, maybe an option in my 240 (without A/C so same style squirrel cage fan). Maybe it'll even move some air instead of making noise only!
JW240 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 09:43 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2016, vBulletin Solutions, Inc.