Trumatic C4002 circulation fan

Fold the tabs back 20190607_155647.jpg
Look out for the notch in the cover that aligns with the bump on the rear end.
20190607_155748.jpg

One thought. Make sure that the brush braids are not so long that they will short on the motor casing.

When all back together connect to a 12v battery. White to pos black to neg.
My motor spun up and ran a treat
Happy days

M
 
As you say these carbon brushes can easily be filed down to make them smaller and agreed you need to watch out for any small springs before they disappear into the distance.

Another tip is using an old tooth brush to clean around the commutator.
 
As you say these carbon brushes can easily be filed down to make them smaller and agreed you need to watch out for any small springs before they disappear into the distance.

Another tip is using an old tooth brush to clean around the commutator.

That is a good tip. Also having a good worksurface and taking it steady. Truma uk were not a great deal of help. Their answer would probably have been to buy a complete new boiler. For the sake of 5 quid it is worthwhile having a go at new brushes.
 
Hello Martin P ! I have C 6002 EH model and fan not working... Whether that newer fan, 34020-61300 , worked well?
 
Well.
The fan worked well for a couple of trips , probably ten days use in all but we now have a circuit board fault. Whether it is linked to the old fan brushes burning out or the new fan compatability issues I couldnt currently say. Still looking for a fix for the circuit board. If you cant find the exact motor I would probably go the new brushes option. I am still looking to get our circuit board repaired but truma are very unhelpful about releasing circuit diagrams etc
 
There are firms which repair all makes of ECU,s perhaps one of them might look at your circuit board ?
 
Have the same problem and totally agree about Truma service support, they really want me to purchase a new unit. I'm going to see if i can find a company to do the overhaul of the motor
 
Martin!
Can you upload pictures from pcb boards on both sides? My friend is an electronics expert. He can look at them..
 
Just had my Truma circuit board back from being repaired. Found a guy who specialises in these. (And other boards). His name is Richard from A and R electronic development ltd. Various board repairs are at various prices but mine was £50 for a full diagnostic check then £100 for the repair. The repair is guaranteed for a month against the same fault recurring..
Richard is pretty knowledgeable about Truma stuff which I found a bit of a lifesaver
Should anybody else need a Truma circuit board repaired here are his contact details.
Www.arelectronics.co.uk
Rsol@arelectronics.co.uk
01543 579302

I will post follow up when fitted at the weekend
 
Further to previous posts.
The fan motor from the later model truma does not appear to be a straight swap.
After running for a couple of weeks worth of trips the Mosfet transistor on the board went again. The measured resistance of the two motors is different so presumably this is what took out the mosfet. Also a 1.6at slow blow glass fuse.
I have now refitted the old fan motor which I repaired with modified brushes as per my earlier post.
Mosfets to fit (I will post the id number later) are available on amazon for about 10 quid for 5. I had a practice soldering and de soldering on an old circuit board and it was a fairly straightforward job once I had the right tools, solder and flux etc
Now running again. All fingers crossed
 
Perhaps ought to say that this mosfet is of the normally open (off) type.
If it fails then it seems to go to permanently closed ( on) The result of this is that failure results in the fan motor running permanently. Even if the heater unit is switched completely off at the thermostat
 
Last edited:
Update
Now running ok
It would seem that the motor from the later model combi is not a straight swap.
Measuring the resistance of both motors to compare , the original gives a reading of 2.6 ohms and the later gives a reading of 1.6 ohms. ( DC motors are a bit more complicated than this but it gives a guide).
Using current is volts divided by ohms
The original motor would pull 4.6 amps
The later motor would pull 7.5 amps
As the MOSFETs are happy up to about 5 amps it seems likely that the latter motor is what caused my circuit board problem.

To summarize
If you have a fan motor problem and a direct motor replacement is not available then the best repair would be to try replacing the brushes as detailed above several posts back
 
Update
Now running ok
It would seem that the motor from the later model combi is not a straight swap.
Measuring the resistance of both motors to compare , the original gives a reading of 2.6 ohms and the later gives a reading of 1.6 ohms. ( DC motors are a bit more complicated than this but it gives a guide).
Using current is volts divided by ohms
The original motor would pull 4.6 amps
The later motor would pull 7.5 amps
As the MOSFETs are happy up to about 5 amps it seems likely that the latter motor is what caused my circuit board problem.

To summarize
If you have a fan motor problem and a direct motor replacement is not available then the best repair would be to try replacing the brushes as detailed above several posts back

Hello from Finland. I broke my C 6002 EH fan motor from my motorhome and replaced it with a newer model motor that damaged the circuit board mosfet. The problem is that the newer fan motor gives a voltage spike to the mosfet when it shuts down and breaks the mosfet (IRF4095). Mosfet breakage can be prevented by installing a 51v zener diode in the mosfet. Since then, the new fan motor has been operating normally without breaking the mosfet.
Zener.jpg
 
Hello from Finland. I broke my C 6002 EH fan motor from my motorhome and replaced it with a newer model motor that damaged the circuit board mosfet. The problem is that the newer fan motor gives a voltage spike to the mosfet when it shuts down and breaks the mosfet (IRF4095). Mosfet breakage can be prevented by installing a 51v zener diode in the mosfet. Since then, the new fan motor has been operating normally without breaking the mosfet.View attachment 90107
Hello,

please Toni M, save my soul. Just before holidayss, our fan broke up. Can You please tell which motor You bought, and i do not understand by the picture how did You connected/soldered diode.
Thanks for help.
 
Hello from Finland. I broke my C 6002 EH fan motor from my motorhome and replaced it with a newer model motor that damaged the circuit board mosfet. The problem is that the newer fan motor gives a voltage spike to the mosfet when it shuts down and breaks the mosfet (IRF4095). Mosfet breakage can be prevented by installing a 51v zener diode in the mosfet. Since then, the new fan motor has been operating normally without breaking the mosfet.View attachment 90107
That back emf can sneak up behind you!
 

Users who viewed this discussion (Total:0)

Back
Top