Blower Fan Blues Pt.2

mikeonb4c · Post by **mikeonb4c** » Mon Nov 26, 2007 10:38 pm

Interesting this, given the debate about deleting threads etc. The thread called Blower Fan Blues is locked and its a shame as it has some excellent content and it would have been good to continue on it and thus avoid another new thread.

But to get to the point, I've been thinking that my front blower doesnt blast out air even though the fan is working fine on speeds 1-4. There is a slight buffeting noise from he system, and the fan motor seems to stop quickly when switched off (not that I have another Bongo to compare it with). I wonder if the fan is perhaps a little bit tight.

So I took the intake cowl off and spun the fan motor. It wasnt especially tight but neither did it keep spinning after being given a flick. Has anyone got a view on how free running the blower fan motor ought to be? Jefferson, in his Blower Fan Blues postings, reckoned that having oiled the fan motor and cleaned out the matrix, the system really chucked out a lot of air. I would describe mine as being as good as that though it is quite adequate.

Also, I think I can see how to remove the unit, but if anyone has an idiots blow-by-blow guide I'd be grateful. The Bongo workshop manual doesnt seem to say anything about removing the blower fan (in fact I suspect there is quite a lot it doesn't say!).

All input gratefully received. Thanks chums

Great to have another little job to do - I'd get bored and spend £ on diesel driving it about if not

Mike

missfixit70 · Post by **missfixit70** » Mon Nov 26, 2007 11:04 pm

I was sure I'd remembered seeing a blow by blow ( no pun intended - honest

) of the fan removal by someone not long after I'd done mine, but couldn't find anything when I just had a quick look. Pruned?

It is definitely not a difficult job though as i did it within a couple of hours with no rushing about or any real info on the fan bit itself, unfortunately I didn't think to take any photos as I was doing it & my memory of the specifics is cack, sounds like it needs doing though, before it gets terminal.

waycar8 · Post by **waycar8** » Mon Nov 26, 2007 11:06 pm

hi mike the fan isnt that powerfull anyway, when you turn the motor by hand it doesnt spin freely like a wheel, you should be able to get a around 4 ish revolosions when you give it a spin by hand, when i replaced mine after my repaired one burnt owt, that was the same sort of spin, then when i got the replacement that was the same

, but its worked fine since i replaced it.

i checked a few different bongos front heater controls for my own peice of mind and they were all kicking out the same sort of air speed.

francophile1947 · Post by **francophile1947** » Mon Nov 26, 2007 11:34 pm

missfixit70 wrote:I was sure I'd remembered seeing a blow by blow ( no pun intended - honest ) of the fan removal by someone not long after I'd done mine, but couldn't find anything when I just had a quick look. Pruned?
It is definitely not a difficult job though as i did it within a couple of hours with no rushing about or any real info on the fan bit itself, unfortunately I didn't think to take any photos as I was doing it & my memory of the specifics is cack, sounds like it needs doing though, before it gets terminal.

Highly unlikely it's been pruned - Techie Stuff still has postings from 2004

mikeonb4c · Post by **mikeonb4c** » Tue Nov 27, 2007 12:36 am

Thanks Wayne (and MissF). Maybe mine is just showing standard behaviour then. Mind you, it doesn't sound like a difficult job and might make an interesting little exercise, but at least I'm persuaded it probably isn't something to fret about. Must say that - esp. in conjunction with the aircon/demist - it does its job OK

brorabongo · Post by **brorabongo** » Tue Nov 27, 2007 12:59 am

From what I can remember, which is not a lot. I disconnected the motor, and removed motor complete in it's ducting, I'm sure though it meant all of the large square ducting was removed by the end, and all by undoing a few nuts/screws. Nothing drastic, to worry about. I do remember that that was my first job on my then newly purchased "dream machine"

I chicking out of sorting the bearing, and just got a replacement from an online breakers, along with a resistor.

Whilst you have all the ducting out, it will be a good chance to check out the air con rad for dirt etc

missfixit70 · Post by **missfixit70** » Tue Nov 27, 2007 1:13 am

Good opportunity to give the ducting a damn good clean too, goes a long way to eliminating any smells too. I definitely noticed a huge improvement in fan output after rebuilding & regreasing mine

mikeonb4c · Post by **mikeonb4c** » Tue Nov 27, 2007 9:35 am

Brora - yep that seems to fit with what I saw under the bonnet last night (a couple of nuts and 3 screws). Oh dear, all sounding a bit double entendre this

MissF - v interesting to hear someone else confirm fan efficiency was improved. From what you say, it sounds like you did have a go at stripping and relubricating the bearing. Is that right? Did you find it straightforward? What kind of oil should I use if so (I've got light oil like 3 in 1 / cycle chain oil handy - would that do?)

Thanks for all the tips. useful information this (please don't delete the thread Mr Moderator if you are reading this in 6 months time

)

Shad · Post by **Shad** » Tue Nov 27, 2007 10:59 am

Hello Mike,

My fan gave up the ghost last year and I repaired it a couple of months ago. I followed the BF excellent fact sheet step by step and saved a fortune. My bearings had completely siezed and the resistor pack soldered connections had broken too. All repaired and back to good working order. I used pushbike-bearing grease as I had this handy, it seems to have done the trick.

A man of your abilities would have no problems doing any of this, but I'm around on Saturday so can pop round to show you what I did when I return your oil can then if you fancy.

Cheers, Shad.

Rhod · Post by **Rhod** » Tue Nov 27, 2007 1:18 pm

I just replaced my fan & it's pretty straightforward - took maybe 30 minutes to do the whole job after I'd worked it out.

I'm writing from memory, but the way that worked for me was roughly:

1) Remove 2 push-clips at front of "wide-mouthed" ducting & pull ducting off.

2) Disconnect fan electrical connector.

3) Unbolt fuse box & lay to one side

4) Undo 2 nuts (horizontal) behind fuse box which hold ducting on

5) undo 3 screws (vertical) holding the fan housing/ducting - 1 on right, 2 on left.

6) undo 2 nuts (horizontal) at the rear right holding the fan housing/ducting to the rear bulkhead.

7) Lift & manoeuver the plastic ducting/fan housing assembly out of the bonnet space

8. undo 3 screws on the underside of the fan housing to extract the fan.

Think that's it - I might have missed a screw or bolt out but it's all self explanatory. Don't think it makes any difference which order you unbolt it in really.

Rhod

Rhod · Post by **Rhod** » Wed Nov 28, 2007 3:54 pm

I'd definitely welcome a description of how to overhaul the fan motor itself. I gave up on mine when it refused to come apart in the way I expected it to due to the amount of resistance. I'd still like to refurbish it against future problems with the replacement though.

Post by **Ian** » Fri Dec 14, 2007 12:22 pm

mikeonb4c wrote:...so we really should see if some of the excellent advice above could be incorporated in the factsheet to give The Complete Guide to Fan Overhaul. I wonder if our poor overworked BongoMeister (and I'm not being sarcastic here) might put it on a wish list

Sorry, only just spotted this. If someone out there wants to write a guide, I'd be only too pleased to publish it as a fact sheet.

waycar8 · Post by **waycar8** » Fri Dec 14, 2007 9:53 pm

i am sure their was a fact sheet already on how to strip the motor

mikeonb4c · Post by **mikeonb4c** » Sat Dec 15, 2007 12:50 pm

waycar8 wrote:i am sure their was a fact sheet already on how to strip the motor

Yea I thought that too. But looking at the factsheets, there seem to be two but only one of them refers to fixing a seized motor. - the one called 'Fan Speed Resistor'. It is well organised, with pics. and but has no specific advice on how to remove and dismantle the unit so would benefit from the splicing in of a little information (maybe from this thread). The other one is called 'Front Heater' and seems more of a cut n paste of info from threads. It mainly repeats what the other factsheet says.

If Ian is reading this, maybe the 'Front Heater' factsheet could be absorbed into the other factsheet? It is confusing having two. I'm not sure the 'Front Heater' one says anything not adequately covered by the 'Fan Speed Resistor' factsheet. The final factsheet would benefit from retitling, maybe to 'Front Heater Fan and Resistor: Removal and Repair'. It would be a very useful factsheet as the wonderful workshop manual seems to contain nothing on this subject at all

Again, if Ian is reading this, could I make a plea for the factsheet index page to have the listing left justified. I've done a lot of work producing both printed material and web based material and best practice is to avoid centre justification as it makes it much harder for the eye to run down a list and spot things. This in turns causes more people to miss seeing an entry. Also, maybe the index should be put into useful sections (engine cooling / heating / ventilation, electrical and battery, bodywork and trim, wheels / suspension / brakes, servicing, lighting, accessories etc.)

I'd be happy to do this work (time I did something) if noone else wants to. Bit (very) busy at present so if anyone else felt more able to that would be great, but I have basic HTML skills etc. so could do it. Advise me what to do if so Ian

Mike

Post by **Ian** » Sun Dec 16, 2007 2:11 pm

Mike, I'm not sure I agree that this should be amalgamated in to one fact sheet. I like to keep the fact sheets as concise as possible, and I think changing the fan speed resistor, and removal and maintenance of the heater motor/fan assembly, are 2 separate tasks and require 2 separate fact sheets. But I am open to persuasion.

If you (or anyone else!) want to go ahead and re-write the existing "Front Heater" fact sheet, then it should be written in Microsoft Word, and I can email you the original document for you to play around with. When it's done, I can format it to correct style etc. PM me for further details.

Good point about the left justification of the index, and I will make the change in next couple of days.

By the way, the reason the Workshop Manual does not cover the aircon or heating systems is that this was originally issued as a supplement by Mazda Japan. But there was little interest in getting it translated; see here
http://www.igmaynard.co.uk/bongo/forum/ ... hp?t=14818