Fans

[helen&tony]

Hi
I check on the functioning of the rad. and scavenger fans from time to time, but I have been toying with the idea of making up a little indicator panel with LEDs on, to show when the fans are actually running as I'm driving, or sitting in traffic. I thought of the following indicators:-
1 for the rad fans on speed 1
1 for the rad fans on speed 2
1 for the scavenger fan
If made up on a neat panel, I'm sure it would help to know that another part of the cooling system is operating fully, considering the problems that can occur, and may help with a rapid diagnosis of a sudden "event"
Cheers
Helen

[nfn]

Helen, that sounds like a good idea. I'm not sure that my rad fan has ever gone to level 2, but it would be another useful piece of information to have. With all gauges -- TM2, low coolant, Mason, as well as a fan gauge, the bongo cockpit will start to resemble an aircraft cockpit!

[helen&tony]

Hi
Absolutely!!!...rows of switches doing nothing but switching LEDs on, labelled "Warp Drive", "Arm Photon Torpedoes", etc.
OOOOHHHH what fun
Cheers
Helen

[The Great Pretender]

And one for "am I getting paranoid".

[helen&tony]

Hi
TGP
Yes...I like it!!!
Actually, I wondered about the scavenger fan more than any other, as we had that much snow last winter, that it scooped into the engine bay via the fan....frozen snow isn't too good for the electrics when it just sits there for weeks, and I wondered whether some of the electrics would work again!!!....it also got that cold that the diesel froze. The other worry (only slight, mind you) is that I've never heard the rad fans on speed 2.....possibly a good thing!!!, but the rad fans only seem to operate when the air con. is operating???....The TM2 shows normal, and , guess what, the standard temp . gauge grins at me in it's usual normal mode
By the way, when I renewed the radiator, I took your tip and used 30% coolant for the summer, and when I put the rest of Flippa's 14 hoses on, I'll go for a 50% winter mix....hoping that this winter doesn't break the Bulgarian record of minus 38 C. ....paranoic, ? moi ?.....Yusssireeee
Cheers
Helen

[Aethelric]

Hi
TGP
Yes...I like it!!!
Actually, I wondered about the scavenger fan more than any other, as we had that much snow last winter, that it scooped into the engine bay via the fan....frozen snow isn't too good for the electrics when it just sits there for weeks, and I wondered whether some of the electrics would work again!!!....it also got that cold that the diesel froze. The other worry (only slight, mind you) is that I've never heard the rad fans on speed 2.....possibly a good thing!!!, but the rad fans only seem to operate when the air con. is operating???....The TM2 shows normal, and , guess what, the standard temp . gauge grins at me in it's usual normal mode
By the way, when I renewed the radiator, I took your tip and used 30% coolant for the summer, and when I put the rest of Flippa's 14 hoses on, I'll go for a 50% winter mix....hoping that this winter doesn't break the Bulgarian record of minus 38 C. ....paranoic, ? moi ?.....Yusssireeee
Cheers
Helen

Hi Helen, I believe the fans only come on at speed 2 when the cooling water is very hot. This is when the engine is working very hard over a long period. It can happen going up long steep hills at a fast speed. You probably would not hear the fans under such conditions Toddling around town. or moving through slow traffic, speed 1 is all thats ever needed.
Now for my guess at the logic behind this:- the fans operate regularly under normal running, particularly in slow moving traffic as otherwise there would be no airflow over the radiator, or for the a/c. So, for longevity of the fans, they are run at low (but adequate) power. The high speed is needed only occassionally, so even though the lifetime of the fans is reduced at high speed, the life is still comparable with the lifetime of all the other bits on the bongo.
So if all of your journeys are flat out, and uphill, the fans won't last indefinitely - but then neither will the engine!

Cheers

Dave

[helen&tony]

Hi Dave
Thanks...I'm more interested in WHEN they are actually working than anything else...I do a fair bit of hill driving, but not huge distances, and rarely go over 50 MPH, as I enjoy the scenery too much , so the Bongo doesn't get much of a workout....however, we may go touring next year, and we're getting the Bongo thoroughly "sorted out"
Cheers
Helen

[Grahame at work]

Hi Helen&Tony

I have such a display.

It is made up from an LED bar array with 5 LEDs in a line. I have mounted this into a switch blank such that the line of LEDs is vertical in the centre of the blank. Suitable series resistors are ‘potted’ into the void behind/inside the blank and these are wired out to the ECU terminations.
I have the bottom LED for the ‘stage 2’ fan, next is the stage 1 / AC fan, the middle is the scavenger fan, next presently unused and the top is connected to the terminal of the fan - stage 2 wiring.

Thus I have an indication of the ECU switching all three fans and also an indication when the radiator (offside) fan is rotating. I say rotating because the air flow past the blades when the fan is un-powered is sufficient to generate a voltage which turns on the LED on, albeit dimly (depending on speed!).

Some may think my arrangement is not acceptable because the LEDs are ON when the fans are not – the LEDs go out when the fans are driven. But I think its OK – could have arranged it the other way round but didn’t plan it well enough.

As a matter of interest since I fitted it I haven’t managed to get the stage 2 fan on yet – and I have tried several times – you need a long slow hill to do it.

Regards Grahame

PS I'll try posting a photo when I get home tonight

[helen&tony]

Hi Grahame
Interesting...perhaps you cold PM me some instructions....and photos..I haven't got access to wiring details
Cheers
Helen

[Grahame at work]

Ok Helen,

But I'm affraid I'm up to my eyes in last minute 'improvements' before the trip to Poland so it will be a couple of days while I get the info together. (hence no photo last night - still fitting an extension to my table support bar at 10pm )

Regards Grahame

[helen&tony]

Hi
Ta, Grahame....much appreciated when you have the time
Cheers
Helen

[Grahame at work]

Helen - I haven't forgotten -

just working up to clearing my work bench - it got totally trashed as I worked on joanie for Poland - no time to clear up after me

SO now we are back I'm trying to get round to all those little things I said I would do.

I'll be in touch soon.

regards Grahame

[helen&tony]

Hi Grahame
Many thanks....much appreciated
Cheers
Helen

[Lloydy]

Hi all,

Can anyone instruct me on how to check your fans are working? I can never hear mine and am wondering if they work?!

Secondly... What is the scavenger fan please?

Cheers,

Lloydy

[Grahame at work]

Hi Lloydy

Secondly... What is the scavenger fan please?

This is the fan mounted in front of the engine just forward of the passenger foot well - it is used to keep the engine bay from getting too hot. Only comes on while driving if its very hot outside and you are in slow traffic or it can come on after you have stopped, switched off and the heat from the engine builds up - it is controlled by a sensor mounted behind the hand break via the ECU.

Can anyone instruct me on how to check your fans are working? I can never hear mine and am wondering if they work?!

The 2 fans mounted on the back of the radiator come on together. At a 'low' speed when the A/C is switched on, although they run intermittently, and when the engine coolant gets above a certain temperature.
They come on at 'high' speed when the engine coolant gets very hot - 108 C and this should only happen when you are going very slowly up a very steep hill.
To check them out switch on the A/C (engine running) and note the noise & air flow (watch where you put your hands) and then disconnect the coolant temperature sensor which is above the starter in the side of the engine block just below the head, the connector is strapped to the bar behind the cable loom. When the sensor is disconnected the fans are driven at high speed and you should hear and feel a difference.
Check both fans are turning OK as one member had broken blades although the fan motor was turning.

Regards Grahame