Front heater / electrical problem?

[Four Oaks Bookworm]

Front heater has been very 'weak and weedy' for a long time, only really effective on no 4 setting (It's the old style heater, not the climate control). Rear heater better but still not full strength.

Last week front heater packed up altogether, not blowing at all. Rear heater actually functioning better/stronger now.

Have changed 30A fuse for front heater, no difference.

Don't know if these two things are also related/significant, but:
- replaced alternator belts last month as one failed
- front electric windows were also slow to rise, now much quicker after heater stopped working

Any advice welcome, thanks!

[g8dhe]

Have you looked at the thermal fuses in the block in the centre, these tend to pop if the motor is having problems and drawing excess current.

They heat up with excessive current, melt the solder and pop open, just use a soldering iron without any extra solder to melt the existing solder and stick the tabs back down again.

[Four Oaks Bookworm]

Thanks, where do i find this (techie idiot here..) is it with the under-bonnte fuses, or behind the switch panel on the dash?

[g8dhe]

Its where the probes are located in the picture below, there is a protection cap that needs unscrewing first;

[Ian]

If a new fan speed resistor is required (also known as rheostat) there are 2 types depending on the type of aircon/heating you have. See bottom of this page: https://bongoland.co.uk/product-category/electrics/

[Bongoplotter]

Thanks for the advice. Motor has now been replaced and there is a small amount of air when on windscreen setting, but nothing from the other directions; feet, face etc. even though it sounds as though the motor is working. The replacement motor is second hand, so is it likely to just be a dud, or is it the way it has been fitted? (Electric mirrors were fine before the motor change, and now they are not working )Any advice much appreciated, thank you.

[g8dhe]

Does the speed of the motor vary as you change the speed setting ?
Have you checked that the control disks in each footwell are all correct ?

Can't see that the electric mirrors should be associated with any problems involving the wiring or controls.

[Bongoplotter]

Thanks, the speed does vary, but minimally. It’s all very weak. There is no movement on the passenger side mechanism, but there is on the driver's side now that I've pushed the silver ring at the end of the cable into place. It was loose, as in the photo. Thanks very much for your advice. I guess both sides should work together?

[g8dhe]

Passenger side varies the amount of air passing thru the heating matrix, drivers side moves the vanes to direct the air to the different locations.
You should find that the speed controls vary the motor speed quite a bit. Have you checked the state of the fan itself and of the control resistor ?
see here for the fan http://www.g8dhe.net/bongo_images/air_fan_cleaning/
and here for the position of the control resistors and the thermal fuses that protect them, under a protecting cap

[Bongoplotter]

Thank you g8dhe. The old motor was sitting in water so making the drain hole bigger, as you suggest would clearly help. A clean-up also sounds like a good plan. Thermal fuses have been checked and are ok. Please forgive my total techie ignorance, but what is most likely to be the reason for the passenger side mechanism not moving? Really appreciate your advice, thank you.

[g8dhe]

The passenger side heat control on your manual system is controlled by a Bowden cable (bike brake cable type) running from the slider on the panel down to the arm that turns the vane inside the air box. So as you move the slider the arm should move turning the vane internally.
Controls
http://www.lushprojects.com/bongopartsm ... 1of02.html

airbox
http://www.lushprojects.com/bongopartsm ... mgno=.html

[JulesMartin]

If you slip the ring end of the cable off of the lever of the heater box on the passenger side and check to see if when moving the heater control the top slider on the heater panel from left to right that the cable inner also moves in and out of the outer cable. Next check to make sure that the outer cable is secured against the heater box casing. It may be as simple as the retaining clip has fallen off. if all this works then before you put the ring part of the cable back on the lever, with your fingers see if the lever going into the heater box moves easily. when I replaced the bulbs in my heater control I managed to get that cable trapped and jammed somehow. it may be possible that the same has happened with yours. Another check just in case the matrix is blocked is to get the van up to full running temperature and under the bonnet behind the heater unit you will just be able to see two hoses going through the bulkhead on the passenger side. reach down carefully and check that both are hot one will be slightly hotter than the other showing the matrix is doing its job. I've purchased a hand held digital temperature gauge which has a lazer beam in it. you just point it at the thing you want to check its temperature and it will give you a read out on its display. Really useful with bongos for checking various areas of the cooling system.
133273788997 | eBay

[Bongoplotter]

Thank you!!
Will have a good look tomorrow

[Four Oaks Bookworm]

Thanks for all your advice (Mr Bongoplotter here..). We've checked all the cable linkages (all fine), all the fuses/relays (also fine), and replaced the heater motor itself.

The power from the blower is still pretty weak, but it immediately goes up to proper strength when you select the slider to 'recirculate'. Another related issue is that when you move the lower slider to change the direction of the air (from R to L, so from windscreen to feet), the slider jams and won't return to 'windscreen' unless you manually move the large plastic control disk to the left of the driver's footwell. The cables on both sides move freely when they aren't attached, so does this suggest
- a problem with the spindle on the control disks, or the disks themselves?
- a blockage in the ducting when not set to recirculation

thanks!

[g8dhe]

Can't say I have heard of problems with the vanes inside the airbox before but your description suggests that this might be the problem if the cables move freely themselves when disconnected from the disk. Does the disk move reasonably smoothly when its free or is there much friction at points?
The fact that the air flow improves on re-circulate also makes me suspect that the vanes in the airbox might be the problem, but again not heard this problem mentioned before on the forum.
The details, as such they are, of the vanes is shown here http://www.lushprojects.com/bongopartsm ... mgno=.html