108 cdi heater switch
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The switching is done in the control unit which that speed dial is attached to. Its possible to remove the switch but i dont know if its available to buy seperate
The switch looks like its made as part of it but carefull removal is possible, though there is not much that can be repaired in it. Worth checking if its sold alone though
Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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before you go to the expense of a new controller...... do you know anyone else with a 638 (ANY model)
if you do.....
remove the heater resistor block from both and swap the replacement for yours....... the resistor block is halfway between the left hand vent and the central console..... 2 screws on each end of a multiwire plug and socket... and it then pulls out of the heater air pipe.
I've been having problems with mine and a couple of others, all due to clogged pollen filters putting too much strain on the system.
the system works by switching 4 resistors in and out of circuit with the rotary control and a heat sensitive fuse.
it switches in the appropriate resistor or resistors and then adjusts with the rotary.
if one section isn't working or only no4 is working, it might be a blown resistor or resistors.
easy to check by substitution........ may or may not be the problem.... I've got 1 completely blown resistor pack, 1 part blown (working on 3 and 4) and 1 blown thermal fuse.....
only the fuse is fixable (no fan control at all) in an electronics shop (not merc) for about £1.... the blown resistors need a new resistor block from mb or scrap.
heater problems are rarely because of use or age... almost always a blocked pollen filter overloading it
if you do.....
remove the heater resistor block from both and swap the replacement for yours....... the resistor block is halfway between the left hand vent and the central console..... 2 screws on each end of a multiwire plug and socket... and it then pulls out of the heater air pipe.
I've been having problems with mine and a couple of others, all due to clogged pollen filters putting too much strain on the system.
the system works by switching 4 resistors in and out of circuit with the rotary control and a heat sensitive fuse.
it switches in the appropriate resistor or resistors and then adjusts with the rotary.
if one section isn't working or only no4 is working, it might be a blown resistor or resistors.
easy to check by substitution........ may or may not be the problem.... I've got 1 completely blown resistor pack, 1 part blown (working on 3 and 4) and 1 blown thermal fuse.....
only the fuse is fixable (no fan control at all) in an electronics shop (not merc) for about £1.... the blown resistors need a new resistor block from mb or scrap.
heater problems are rarely because of use or age... almost always a blocked pollen filter overloading it
Malcolm I don't suppose you have a cure for the sides of the windscreen fogging up ?
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Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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with upto 4 people carried, I've never had a problem provided the pollen filter is in good condition.... removing it will give much greater airflow but the wife has severe hayfever and I like to keep breathing.
in my old tranny, I got 2 cheap plug in fans (5 inch fans) and wired them together... NOT pos to pos, neg to neg but plug to pos, this fans neg to other fans pos, 2nd fan neg to 1st fans plug neg (hope that makes sense)... so the power is daisy chained and the 2 fans work as one but at slow speed.
the fans were in the middle and pointing at the corners of the screen.... worked a treat, even in long traffic jams..... I've just not had a problem with the 638
oh, and the reason for the double wiring..... they were too bloody noisy at full speed.
a couple of compter fans would be ideal.... they are 12v and pretty quiet.
in my old tranny, I got 2 cheap plug in fans (5 inch fans) and wired them together... NOT pos to pos, neg to neg but plug to pos, this fans neg to other fans pos, 2nd fan neg to 1st fans plug neg (hope that makes sense)... so the power is daisy chained and the 2 fans work as one but at slow speed.
the fans were in the middle and pointing at the corners of the screen.... worked a treat, even in long traffic jams..... I've just not had a problem with the 638
oh, and the reason for the double wiring..... they were too bloody noisy at full speed.
a couple of compter fans would be ideal.... they are 12v and pretty quiet.
Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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got it in the neck from the wife with the broken neck (I call it attention seeking)....
aparently I should admit to carrying an extending handle squeegee and sponge.... great with snow and ice, fantastic screen cleaner and able to smack someone in the back seats when totally wet and disgusting.... (the squeegee)
the poor clearing of the screen is due to a wassock of a designer who insisted on putting the speakers in the corners......... whereas if they were an inch further off the screen, the vents could go all the way to the corners.
the same designer did the same to a number of other models... they'll probably never change.
aparently I should admit to carrying an extending handle squeegee and sponge.... great with snow and ice, fantastic screen cleaner and able to smack someone in the back seats when totally wet and disgusting.... (the squeegee)
the poor clearing of the screen is due to a wassock of a designer who insisted on putting the speakers in the corners......... whereas if they were an inch further off the screen, the vents could go all the way to the corners.
the same designer did the same to a number of other models... they'll probably never change.
Well thanks to the wife for clearing that up ! Its a disaster having no air blowing up the sides. I often lose about 12" of visibility when it gets bad. Someone already removed the filter. So unless i blow my eyebrows off with speed set to max then i cant see properly. I may try a fan or go back to gluing fiddely bits to the dash
Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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I suppose the fact that I have a positive pressure system will help (internal air pressure is greater than external pressure) will help as air comes through a carbon filter (I have reactions like a "bubble boy" would suffer) and pump.
I still say I've never really had a problem on the 638, not even before my current system was installed....... if anyone wants the system and freedom from all pollutants, it only costs about £60 a month for the charcoal filters and I do very little mileage these days....
the "dead spot" caused by the speakers is absolutely ridiculous but can be found on several mercs and others.
I have decided to install 2 3inch clear computer fans to the "spare" van and mount them on a single spigot each over the central vents... that way they will keep the corners ventilated in winter and cool the driver in summer.
as to the squeegee and sponge..... its fantastic to clear frost, ice and snow and will remove condensation from the sides....... it doesn't work on front or rear screens as they are "double curved" i.e curve top to bottom and side to side, this means the edges of a squeegee touches but not the middle.... great on the outside but useless on the inside......... just don't tell the grandsprogs.
I still say I've never really had a problem on the 638, not even before my current system was installed....... if anyone wants the system and freedom from all pollutants, it only costs about £60 a month for the charcoal filters and I do very little mileage these days....
the "dead spot" caused by the speakers is absolutely ridiculous but can be found on several mercs and others.
I have decided to install 2 3inch clear computer fans to the "spare" van and mount them on a single spigot each over the central vents... that way they will keep the corners ventilated in winter and cool the driver in summer.
as to the squeegee and sponge..... its fantastic to clear frost, ice and snow and will remove condensation from the sides....... it doesn't work on front or rear screens as they are "double curved" i.e curve top to bottom and side to side, this means the edges of a squeegee touches but not the middle.... great on the outside but useless on the inside......... just don't tell the grandsprogs.
Bridging the plug on the back of the heater controls will allow testing of each speed
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Uzing a HEAVY piece of yire you can bridge the pinz and by doing that you are teting the circuit each coil of the pack . apologie keyboard got milk on it only half orking
Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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it is possible to do this by feel alone or get your head in th left hand footwell.
remove the covering under the dash / top of left hand footwell..... you only need detach the clips on the edge of the dash.
feel or look under the dash... on the extreme left is the fan (big lump) that is visible if the left hand vent is puuled out (not necessary to remove vent but it comes out easily if you pull the extreme top edge and bottom edge of the vent casing DO NOT PULL THE VANES)
there is a long fat tube ((about 4inch section tube) going from the fan to the central switch panel / gear lever.......
about the middle of the distance is a large bunch of wires into a plug / socket.... THIS is the resistor block
the connector can be taken apart
on each end (left end and gear lever end) of the part thats attached to the pipe is a screw... normally a pozidriv no2 screwhead but can be hex headed or hex head with pozidriv centre ( be careful... german pozidriv is often easier to undo with a philips screwdriver)
the resistor block then pulls out.
new heater resistor blocks are about £25 from merc (online from ciceley about £28)
I did my first by getting under the dash (no passenger seat) but others purely by "feel", standing with the door open
malcolm
remove the covering under the dash / top of left hand footwell..... you only need detach the clips on the edge of the dash.
feel or look under the dash... on the extreme left is the fan (big lump) that is visible if the left hand vent is puuled out (not necessary to remove vent but it comes out easily if you pull the extreme top edge and bottom edge of the vent casing DO NOT PULL THE VANES)
there is a long fat tube ((about 4inch section tube) going from the fan to the central switch panel / gear lever.......
about the middle of the distance is a large bunch of wires into a plug / socket.... THIS is the resistor block
the connector can be taken apart
on each end (left end and gear lever end) of the part thats attached to the pipe is a screw... normally a pozidriv no2 screwhead but can be hex headed or hex head with pozidriv centre ( be careful... german pozidriv is often easier to undo with a philips screwdriver)
the resistor block then pulls out.
new heater resistor blocks are about £25 from merc (online from ciceley about £28)
I did my first by getting under the dash (no passenger seat) but others purely by "feel", standing with the door open
malcolm
Vito 114 tourer 2015: Vito 108d 97: 108d 98: Traveliner 2003 ; Aixam; z1100; xbr500; z440 ++++
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I was just idly looking on tinternet and found these people at an excellent price.
by the way......
the cause of the problem is usually a blocked pollen filter although the pack can go phut with no outside help.....
the filter blocks
the airflow reduces
the resistors get hot (upto or over 200deg)
the thermal fuse blows
or
a resistor wire melts
by the way......
the cause of the problem is usually a blocked pollen filter although the pack can go phut with no outside help.....
the filter blocks
the airflow reduces
the resistors get hot (upto or over 200deg)
the thermal fuse blows
or
a resistor wire melts
Fixed missing speed 1 and 2 yesterday. removed the speed switch from the heating controls. Drilled a hole in the side to allow a screwdriver to support the switching plate then bent the end down to restore contact. All speed now fully working again.
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