Bongo front fans not working

[ShaunMc]

We've been trying to fix the front fans in our van after reading other posts about it on here however without much luck so far. The heaters are working as far as we can tell, but there is no air from the front vents.

Our Bongo is a 1996 2.5 TD.

First noticed that the fan fuse (near the battery) looked like it might have gone so replaced this. Also have replaced the fan resistor as old one had gone (2 contacts had come undone). After replacing this, the rear fan/heaters, started working, but not the front.

We then took the fan motor apart, cleaned out the bearings and re-assembled. Tested the fan motor by connecting to an external battery so know that the motor works. Think the problem is the negative wire that the fan motor plugs into, the live wire is getting power but not the negative (checked with a multimeter). Have tried to trace this wire but can't find where it goes to, can anyone help?

Assume there must be another fuse gone somewhere that we are missing (have tried all the fuses in the main box above the fan motor, the box behind the battery and the fuses inside below the steering wheel).

Would be great to hear if anyone has had a similar problem or has any other suggestions!

[windywatson]

Worse case is to just replace the wire yourself. If it is the earth that is missing as you suggest. Then make up a length of wire & if your worried about it requiring a fuse fit the wire with an in line fuse & connect to nearest -ve point or to chassis. Job done & may take you less time than trying to trace the break in the negative wire.

Cheers

[ShaunMc]

Thanks windy - I think we tried that, but once the fan started it wouldn't shut off (but only tested this for a few seconds). Will try again this weekend, lack of light and cold makes working on it midweek tricky!

[cmm303]

http://www.g8dhe.net/bwm/bwmanualp.htm?1995/Page_80

Looks like the fan speed switch and resistor pack are on the earth side of the motor.

[ShaunMc]

Hi Chris, and thanks for that - that would make what we observed above make sense. I'm a bit clueless with electronics (and Japanese) - can you point me at the right bit of that diagram? Many thanks.

[cmm303]

No worries Shaun. I've been there, still am! These diagrams, perhaps initially a little overwhelming, are very useful so worth working your way around them. Their index is at http://www.g8dhe.net/bwm

To your question re the front heater diagram. I haven't worked in this area so spouting a bit theoretical from the diag.
I've assumed you have the manual heater controls (levers and a knob). If you have the auto climate control then we are looking at the wrong diag.!
The circle within a rectangle marked with a big M is a motor, and I'm assuming this is the heater fan
The top wire to this motor comes from the 12v supply via a 30A fuse and relay contact, so must be the supply!
Therefore the bottom wire to the motor must be ground. This goes through the boxes to its right in the diag (resistor pack and switch) and thence down to earth points 6 & 7 (blue circles at the bottom of the diagram)

To find out wire colours click on the red and blue "CC" box at the very bottom of the screen, below the diagram. It brings up a translation of the japanese colour abbreviations.

I hope this helps.

[ShaunMc]

Chris and Windy, thanks a million for the help - we've fixed the fan *kind of*.

With the help of the wiring diagram, we began chasing the connection between the back of the controls and the resistor pack - as a result, we saw that the same 2 pins had blown again on the resistor pack.

What I think has happened is we replaced the resistor pack, but tried running the fan again before we'd fixed the rusted bearing on the bottom of the fan heater, and it's blown exactly the same way again. One messy solder later, and we've not got the fan working on full whack, but not the lower settings, which is likely still damage to the resistor pack, so we've got another replacement.

One further query - we disconnected a 'spring' from the recirculation diverter housing, but can't remember how this attached. It doesnt matter so much, the diverter is still working, but wondering if anyone has any idea how this hooks back in? Photo of the spring below - pointing at it with the screwdriver:



Thanks again for the tips!