front fan stopped working

[mvanderh]

When driving the bongo this morning everything worked fine. Later on today I started up and found that the heater/cooler fan was only working at one speed (low), and later on it did not work at all anymore. The aircon still works, you can hear it going on, but there is no air coming out of the streamers. No matter what setting, what speed, nothing comes out.
The back heater/cooling unit still works fantastic.
Help?

[mikeonb4c]

When driving the bongo this morning everything worked fine. Later on today I started up and found that the heater/cooler fan was only working at one speed (low), and later on it did not work at all anymore. The aircon still works, you can hear it going on, but there is no air coming out of the streamers. No matter what setting, what speed, nothing comes out.
The back heater/cooling unit still works fantastic.
Help?

Could be the classic seized fan motor problem and its desoldered the resistor pack? Very fixable if so - have a search for advice on how to do the job.

[mvanderh]

any idea where i can find advice on the seized fan motor?

[mvanderh]

Since the fan was working at one low speed until I started jiggling the fan control knob, could it be that the knob 'disconnected' at the 'zero speed' option?
If so, how could I check if the knob is disconnected?

Any help greatly appreciated.

[g8dhe]

It could be but the most common problem is that;
Water overflows from the Window screen scuttle plate, because the drainage hole is blocked,
this water falls down over the air ducting and gets sucked into the fan housing,
the water settles at the lowest point which is the lower bearing of the fan motor and corrodes it,
the extra physical resistance causes the motor to draw excessive current,
there are thermal fuses connected to the speed resistors for the fan motor,
these thermal fuses "pop" open causing the motor to no longer work at that speed,
over time all the speeds pop and you no longer get air being blown thru the system!
Now join the club, go to the Factsheet pages and there is a full description on how to repair the corrosion, the thermal fuses and get it all working again!
Its a very common problem ....

[mvanderh]

I joined the club some time ago and looked at the factsheets, thanks.
So, it will be a case of replacing the resistor then.
Is there a chance the fan motor is damaged as well?

[wonkanoby]

chicken and egg situation

bad fan causes blowing of resistor in electronic one or solder joints in manual

[g8dhe]

No need to replace the resistor, the springs can be soldered back down again, try to use the original solder only rather than add any extra just heat them up with a soldering iron and hold them in place while they cool down with the tip of a small screwdriver.

The Fan motor is unlikely to be damaged but will need a clean and the corrosion removed, see the factsheet its detailed in there, you can also drill a larger drainage hole in the case as well to encourage the water to flow out.

[mvanderh]

Got the resistor out. How can I see if it is broken?

[g8dhe]

The springs will have sprung open on the sides!
http://www.igmaynard.co.uk/bongo/member ... sistor.pdf

[the1andonly]

Geoff
the reason for not adding solder?
original being SnPb most people today only having access to Pb free ie higher temperature joint?

[g8dhe]

The reason is I don't know what the exact formulation of that solder is!
Being in a heat sensitive position it might be a low temp solder, hence if you can get away without adding an extra I would, however if there isn't sufficient to create a good joint then adding some standard tin/lead solder should still be ok.

[mvanderh]

Dear all, some more advice required.

An update:
- I checked the fan itself, and it rotated freely;
- I then took out the resistor. Since I did not know what it had to look like if it was broken, I ordered a new one.
- When the new one arrived, it looks just like the old one, so I assume the old one had actually never broken.
- Anyway, I just put in the new resistor pack...and
No result, nothing coming out of the vents.....

So, that leads me to one of two conclusions:
- maybe a fuse has blown ( I never checked that..........)> Which fuse would it be for the front fan, and how do you see a fuse is broken?
- or there must be something wrong with the ventilator speed knob on the dash. I am saying this because if the fan motor would have seized, it would have blown the resistor pack (which I think it hasn't)?

Many thanks for all advice so far, a bit more needed though as you can see (and sorry if i am asking stupid questions)

[g8dhe]

Start with the Bongo Wiring Manual site, the Tabs at the top allow you to find the basics problems without getting into diagrams! Select "By fuse problem" then select the Air Con. the controls have two fuses and the front Fan has one fuse.
http://www.g8dhe.net/bwm

[mvanderh]

thanks.

What does a blown fuse look like?