fan
TRANSCRIPT
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
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APPLYING TO:
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THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O
CX, BEHR heating unit, level 3 modification:
1. The heating fan motor (935) (Bosch CPB 12V 23.404) can be swapped by,i.e. a Bosch DPD 12V 3.26.7 double fan motor from a BMW5??. One of the shaftends (choose the correct one!), must be cut. Cut in the original plastic motorholder with a fixed diameter hole saw. Make a clamp and weld arms to the clampthat fits into the original screw holes. The fan is then pushed onto the shaft andthe motor and fan is placed within the fan housing..
2. The transistor regulator (658) might be upgraded by a MJ11033 (50Adarlington). Extra cooling fin should be added to the transistor. The resistorvalues at the fan control (278) which make up the ‘continuous’ fan speedregulation might be adjusted to fit the new transistor optimally.
3. (This part actually belongs to the level 2 modification)The plus supply lead to the fan motor should be replaced by a heavy onethrough a relay. The same applies to the ground lead, running from the fullspeed relay (745 pin 5), in the consol. Make it short.
4. (Optional:)Remove the consol side cover. Cut a rectangular hole (32x100mm (max)) in theright lower rear corner of the heating unit. The reduced resistant will give anincrease in the total flow. As a bonus - when the temperature is set to cold,some warm air will still come to the feet while cold air goes to the screen. To getfull effect to the front screen it must be possible to close the rectangular hole. Aspecial duct is under construction.
page 1
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 2
The new motor:Bosch DPD 12V 3.26.7 with the turbinfan mounted.The shaft, protruding left -down has tobe cut.The other motor is the original:Bosch CPB 12V 23.404.It is faced the opposite way of theDPD motor.
The new motor seen from above withthe clamp mounted.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 3
The original fan motor with the plastic'funnel' and the turbin fan mounted.The four screw holes can be seen atthe edge of the plastic. Four smallarms that are welded to the clampwhich are secured to the motor arefastened here
Top view.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 4
Below is an illustration of this clamp withthe screws and nuts indicated.The arms has uneven sizes due to the shape of the fan housing.
A clamp was made from 8x4mm ironand an old CX door hinge bolt cut intopieces and welded to the two halfs.
A little bolt and a nut to tighten it ontothe motor.Four small arms was welded to thisclamp.The arms rests on, and are screwedwith the original screws to the fanhousing and this holds the motor in a
steady grip.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 5
This is the original fan regulatortransistor and its cooling fin.It might be replaced by the MJ11033(50A darlington transistor.
The location is behind the shelf inthe passenger compartment. Boltetto the chassi above the floor mat.
At the picture to the right you cansee the added extra black coolingfin. It is hot here since the plasticconnector shield is often meltet.
The same thing is pictured here attop of the table. Though it is an oldand coarse picture you may see howthe fin is fastened.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 6
B Mv
3B33B1 3B2
V
278
3B1
By pulling out the central consol airduct you will see the resistor ladderthat is connected to the fan speedwheel on the left side as seen on thepicture to the left.
This ladder simulate a continuousvariable resistance as a control for thetransistor regulator.
The back of the printed circuit is seento the left along with a snippet of theschematics as you will find it in theelectric documentation, either inHaynes or the original Citroenworkshop manual.
By using the MJ11033 I think it is notnecessarily to do any change to theresistors.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 7
This transistor is close to a direct replacement for the original one and most likelymore powerful.It is probably necessary to replace the old one if a bigger motor is mounted.
I blew up my original by accident so I have not tested it.
To Peter Lohmann
From Knut Steinnes
CONCERNING:
ALL S2 CX S
BEHR Heater system:modifications
BULLETINTECHNICAL
CX 5
CONCERNING:
APPLYING TO:
ALL COUNTRIES
ALL COUNTRIES
THIS DOCUMENT IS TO BE FILED IN: BULLETIN BINDER: Heating System
10th Jan 2006
KNUT'sCUSTOMER SERVICES
AFTER EIGHT TECHNICAL DEPARTMENT
N 1O page 8
5N4
RJ
5N35N2
5N1 5N5
745
N GV
The Heating Fan Full Speed Relay(745) is located at the right side in thecenter consol. (Indicated by the redarrow) The schematics is encircled.
SInce the F.S.relay(745) has a ratherlong ground lead it is wise to replacethis lead from pin5 with a short heavierone to a nearby ground post.
With these arrangements you mayeasily gain 1 to 1.5 volt at the motorwhich makes a big difference.
B
Bl
4B2
J
JJ
J
J
F2
III 6
6B1
J Mv
III 6
6B1
J G
H H
Q
935
4B1
Mv
935, heater blower
+
BJ
R
F
A relay (R) with a heavy lead from battery+, with a fuse(F) might greatly reduce thevoltage loss. Control current to the relay istaken from the plus lead to the fan motor.
5N4
RJ
5N35N2
5N1 5N5
745
N GV
To Peter Lohmann
From Knut Steinnes