'89 Mi16 Blower Motor problem

[Peugeot_Rocket]

I am having some blower motor problems on my 1989 405 Mi16 US model. The fan speed dial will not control the blower motor. The previous owner wired up a toggle switch so that the blower motor can be turned on but only at its highest speed. Upon further inspection, I found that one of the toggle switch's wires are hooked up to the black wire on the blower motor and the other wire to a ground in the chassis.

I thought that maybe the fan speed dial was broken so I ordered a used climate control thing from a guy who parts out Peugeots. I put it in and I still could not control the blower motor at all using the fan dial. So I believe it is reasonable to rule out the control dial.

There is certainly power to the blower motor. It turned on after all and when putting a test light in the clip that plugs into the blower motor, where the red wire is the light comes on. There are three other wires coming into the clip but the test light does not come on for any of them even when rotating the fan speed dial.

Don't these wires control the fan speed? Shouldn't the test light come on? Is it possible that something is wrong with the wiring between the blower motor and the speed control or do you think the blower motor's electronics are bad?

Any help will be greatly appreciated!

[colinbrowne]

Originally Posted by Peugeot_Rocket

I am having some blower motor problems on my 1989 405 Mi16 US model. The fan speed dial will not control the blower motor. The previous owner wired up a toggle switch so that the blower motor can be turned on but only at its highest speed. Upon further inspection, I found that one of the toggle switch's wires are hooked up to the black wire on the blower motor and the other wire to a ground in the chassis.

I thought that maybe the fan speed dial was broken so I ordered a used climate control thing from a guy who parts out Peugeots. I put it in and I still could not control the blower motor at all using the fan dial. So I believe it is reasonable to rule out the control dial.

There is certainly power to the blower motor. It turned on after all and when putting a test light in the clip that plugs into the blower motor, where the red wire is the light comes on. There are three other wires coming into the clip but the test light does not come on for any of them even when rotating the fan speed dial.

Don't these wires control the fan speed? Shouldn't the test light come on? Is it possible that something is wrong with the wiring between the blower motor and the speed control or do you think the blower motor's electronics are bad?

Any help will be greatly appreciated!

ive just put a thread for a similar fault on a 307cc but i havent got a dial
just a display with up and down buttons mine dont use a resisor for the speeds it uses a semi conductor control on an heat sink fitted in the motor
body mine only plays up when its hot weather and the engine has to be running for the fan to work but has you described ive got power on the red
wire put the black to earth and the fan runs flat out i didnt use a buld but
a volt meter when i turned the speed up the voltage across the two small
wires on the semi conductor went down and viceaversa the wires you tested may not light a bulb has they may only be afeed and return not negative and
may be grounded by the electronics (yet for me to prove).

[Peugeot_Rocket]

Well I looked in my 405 electrical book that I have and it shows that the blower switch puts out .2 ohms for low and 2.18k for high. I tried using my ohm meter on the plug that goes into the blower motor and I can't get a reading on any of them. I tried getting a reading on the actual climate control module and I can't get one off any of the wires going into it either.

I'm not sure, maybe I'm using my volt meter wrong. It has an ohm setting but which ohm setting am I supposed to use?

According to the diagram I am looking at, the blower switch wires go straight to the blower motor. There is nothing in between that could be wrong.

Can anyone shed some light on how I am supposed to trouble shoot this.



EDIT: I just read this in my book:
"The blower switch in the climate control module acts as a variable resistor to increase or decrease the current flow from the blower motor to ground, which changes the blower motor's speed."

Ok, so how exactly do I test this without blindly buying a blower motor first?

[colinbrowne]

Originally Posted by Peugeot_Rocket

Well I looked in my 405 electrical book that I have and it shows that the blower switch puts out .2 ohms for low and 2.18k for high. I tried using my ohm meter on the plug that goes into the blower motor and I can't get a reading on any of them. I tried getting a reading on the actual climate control module and I can't get one off any of the wires going into it either.

I'm not sure, maybe I'm using my volt meter wrong. It has an ohm setting but which ohm setting am I supposed to use?

According to the diagram I am looking at, the blower switch wires go straight to the blower motor. There is nothing in between that could be wrong.

Can anyone shed some light on how I am supposed to trouble shoot this.



EDIT: I just read this in my book:
"The blower switch in the climate control module acts as a variable resistor to increase or decrease the current flow from the blower motor to ground, which changes the blower motor's speed."

Ok, so how exactly do I test this without blindly buying a blower motor first?

sorry ive only just got back ,you need to know if its a wire wound resistor
and the switch just selects parts of the resistor there are threads on here
on how to do it ,remove glove box unplug wires off heater motor then turn
motor i cant remember direction but it will turn and then you can remove it
then theres either a wire wound resistor in the housing or theres a semi coductor unit on an aluminium heat sink next to fan.

[PureJoe]

Originally Posted by Peugeot_Rocket

[...]
EDIT: I just read this in my book:
"The blower switch in the climate control module acts as a variable resistor to increase or decrease the current flow from the blower motor to ground, which changes the blower motor's speed."

Ok, so how exactly do I test this without blindly buying a blower motor first?

From your description, you need to

• take out the fuse that controls the heater.
• Fix the Ohm meter to either side of the blower switch and
• adjust the climate control module.

Set the Ohm meter at 2000 Ohm - it should run from around 0 when the blower's on minimum to around max - 2000.

[Peugeot_Rocket]

Sorry it took me so long to follow up on this. I have been super busy but I made some time to work on my Peugeot the other day.

The plug that goes into the back of the switch has 4 holes that wires go into. I wasn't sure exactly which terminals to touch and on which to put the negative and positive from the ohm meter. I ended up trying every combination possible. So, I put positive in the first terminal and then negative on every other terminal. Then, I moved the positive to the second terminal and touched the negative to every other terminal. I did that with all four and then switched tactics and put the negative on the first terminal and then touched the positive to every other terminal. I proceeded to move the negative to the second terminal and well, you get the idea.

Depending on the combination, I was able to get readings that were mostly in-line with what the manual said. When moving the dial I got as low as .2 ohm and as high as 1.9 ohm. So, I didn't quite reach the max ohms that I should but that does show the switch is changing the resistance. I should be getting a response from the motor.

So this effectively rules out my switch correct? Can I now reasonably conclude that my blower motors electronic component has failed? I took the motor to a guy in my area who specializes in small electric motors to see if he could test the electronic component for me. He said that the motor wasn't serviceable because the fan blade thing is pressed on and can't be removed.

So unless there is anything else I can do to diagnose this, should I just go ahead and order a new blower motor?

And since we are on the topic of blower motors, I'd like to know about the reliability of blower motors on the early 405 models. Do these commonly fail or are they in general very reliable? If they aren't prone to breakdown, perhaps I should just order a used blower motor?