BIGJIM13

Guys
have a 93 auto with the c68 a/c - blower motor has been working on and off, so replaced the blower motor...still working on and off, mostly off....
there are no high / low replays for the c68..
is it all controlled by the head control....or are there any replaceable parts to get the blower to come on?
Thanks

SunCr

On the left side of the Evaporator Case is a Blower Module. Low Voltage signals, via the Programmer, come in on the Tan or Brown wire. The Module amplifies them and feeds the Blower. Blower 1 should have an input of 2.5 volts and output of 4; Blower 10 6 volts with an output of 12. The module shares ground with the Blower Motor, so you might check that first for an intermittent. You might also check the Blower Connector since they can draw quite a bit of amps and loose terminals will drop volts and melt wires. Otherwise, check the Module voltages and if the input is there and it isn't running, replace the Module (any Dealer or NAPA has a stocking number). If there isn't an input, the Programmer would be suspect, particularly if everything else - compressor and vent postion - is working. Just be sure to do your electrical checks in manual mode. Auto can/will vary blower speed.

If the Module checks out, the better way to check out the Programmer is with a bi-directional scanner as the Dash Controls communicate with the Programmer over serial data lines. With that, you can bypass the Controls using the CCM link and see what and what doesn't work.

BIGJIM13

Thanks for the reply
can you tell me what the Blower Module looks like? cannot seem to find anything?
Thanks

jfb

I would also unplug the blower motor and jump 12v to the motor to see if it will run. These motors have brushes in them and they don't last forever. The blower control module is located on top of the evaporator housing toward the front and center of the car and is recessed into the evaporator housing and has a socket that a plug from the wiring harness plugs into.

BIGJIM13

Thanks
blower motor was replaced last week, original one only lasted for 14 years, will look for the blower control module! when you say jump 12v to the motor, is it ok to just run a wire directly from the battery?
Thanks

BIGJIM13

Ok - made some progress took out the blower control module - its the module with the medal fins on it right? and this controls the blower motor speed??? Does anyone know what the large square module is that is attached to the right side of the blower motor housing, the number on it is
10177912 04073?
Thanks

jfb

It is ok to use your car battery to supply power to the blower motor to see if it is running ok. There are two controls for the a/c heater blower. One is manual (C60) and it uses a dash switch and a power resistor mounted on the left side of the evaporator housing to control the heater blower speed. The other controller (C68) is electronic and digital and it uses a blower control module also located on the left side of the evaporator housing.

BIGJIM13

Thanks - I have the c68..so is it the opinion that if the fuse is good and if I jump the motor and its good - then the fault is in the blower control module and needs to be replaced? it there a way to check the blower control module before buying a new one?

Thanks guys - great forum!!

BIGJIM13

SO if I finally get the blower motor to start blowing - after hitting everything with a hammer - then after a while the volume reduces all by itself, is that an indication that the blower motor control module is bad or on its way out?
Thanks

jfb

I don't advocate hitting things with a hammer to make them work! If you tap on the control module and can make the blower work, I would assume that you have a poor connection to the module, or the module has some kind of problem. The motor and the module are not the only components that are suspect, the control head in the dash is also suspect and can be worked on by yourself for typical problems they have. You can remove the control head and use some electrical contact cleaner on a Q tip and wipe the pins on the socket on the rear of the controller and try it again. If you still have trouble, take the control head apart and wipe the circuit board fingers and the spring contacts that make connection to the top of the circuit board and reassemble and give it a try. You can ask, but I don't believe any parts places can test the motor control module.

BIGJIM13

Thanks
but over the years I have found that the hammer technique works quite well!!!!
anyway I have removed the control head and use some electrical contact cleaner on a Q tip and wipe the pins on the socket on the rear of the controller, reinstalled - no work.....went out later and blower came on...
later would not work....would everyones best guess be that it is a bad
blower motor control module??

jfb

It could be, but you haven't gone far enough with cleaning ALL of the connections in your a/c heating control head. You only cleaned the connector pins, there is a row of gold plated fingers on the end of the circuit board inside and also a number of V shaped springs that make connection to the top of the board. All those connections need to be cleaned with electrical contact cleaner.

BIGJIM13

Thanks - cleaned all gold plated fingers on the end of the circuit board also.....we must have differnet control heads, there are no V shaped springs in my unit.....took everything apart down to the end...
mine is a c68 - anyway, thanks for the comments!