simon28

Heater blower

7 posts in this topic

Hope you guys can help me with my issue

 

My heater blower stop working at any speed.

Here is a list of what I did so far

 

1- Check fuse = OK (try another one also)

2- Check voltage when blower motor disconnect = 12.5VDC

2- Check continuity on the resistor pack = Looks good to me (no open circuit)

3- Remove blower motor and add some lube (Penetran + WD40) on both end of the shaft

   - draw 16amp at start and 9amp running

4- Did the same amp test with a brand new 451 blower

   - Draw 15amp at start and 8amp running

I think my 16 years old blower is OK

5- Mesure Voltage when connected to the blower motor = 0VDC even with the switch to speed 4

CHeck again with motor disconnected = 12.5VDC.....

6- Try to connect the 451 blower... same result = Not turning and 0VDC when switch turn on to speed 4

7- Try to use a relay to supply the blower direct from the battery and still using the original switch (1 speed only) = Nothing

   - Even closing the relay (coil) have the voltage to drop to 0VDC

 

My result so far

1- Blower motor is good

2- Switch is good

3- Resistor pack is good (I Gues)

4- Something cannot supply any amperage to the blower motor connector?

 

What it can be?

Thanks a lot for your help

Simon

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youre going to have to trace back that circuit and find the bad connection

 

 

 

or possibly the speed module...i have no idea what smart used for speed controls ..i never had problems with mine

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It looks to me that your switch is faulty.

 

7- Try to use a relay to supply the blower direct from the battery and still using the original switch (1 speed only) = Nothing

   - Even closing the relay (coil) have the voltage to drop to 0VDC

 

Most common fault is resistor pack  and mine failed about 15 years ago.  I solder repaired resistor pack and it has been good ever since.  I have also repaired faulty blower switches on 450 Smarts not belonging to me.  

 

I suggest you use a test lamp when fault finding as much quicker.

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I bought a new car just to have a heater. Old 2008 chevy Impala.

 

This will give me time to properly fix the heater on the smart. I have connected the blower directly to the battery. It run at full speed.

In traffic, the blower cool down too much the engine coolant so I loose all my heat....

I will fix this issue this spring with more time to spend on this little car.

Thanks for your reply

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Block off the rad completely but make sure you only drive it this way when below lets say 10 degrees celcius.....I find it works good....it also allows engine temps to heat up quicker. IF the blower runs at full power when using 12 volts it must be your switch not being restricted voltage wise.....no..?  That toaster wire inside the heater box faulty?  OR wiring from it bad..?

 

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Checking the circuits is done with an important consumer (control lamp)!
Some circuits may appear good to the measuring instrument, but when a significant current passes through them, they are no longer good.
There is an imperfect contact somewhere... at the resistors, at the switch, etc.
Possible at and at SAM. At SAM - through N11-1 (2.5mm2 black-red)

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Also, take rear lights off car completely and open up the unit....I found the tracks for each wire to be corroded and in one case broken.  Beware they can be brittle....but they also can be repaired if you have soldering skills....also the plastic can be brittle so do this in a warm area or soak them well in hot water to help with cracking the  lenses or body of the light clips etc.....it's not hard so to speak just take your time.

 

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