Dispatch Heater Fan Problem

Simonh04 · Post by **Simonh04** » 17 Nov 2008, 18:39

Hello there to all. I'm new to this so thanks to Google for finding your site and to any kind souls that reply.

My Dispatch is a 2003 model with a 1.9 DW8 (non turbo) engine, ever since I bought it just over a year ago the fan has had a mind of it's own, nothing drastic but the blower speed would at times change of its own accord.
Recently it just stopped completely, it did kick in again with the slider on full and after a good slap on the dash but I made the mistake of moving the speed slider and ever since its been dead.
The slider box has been dismantled and cleaned, I've played with the wires, even tried another motor albeit second hand, nothing has made any difference.
The cold isn't a problem but there is virtually no air movement even when travelling at speed so visibility can be poor and thats not safe for anyone!

I spent last night reading numerous posts about similar problems but am unsure as to how relevant the systems on Xantia's etc are.

Is it likely that my ignition switch could be the culprit?
Does the van have the same resistor pack as the cars?
If so where might it be hiding?
Does anyone know which relays are relevant to this vehicle and the blower motor?
Does anyone have access to a wiring diagram?

My local Dealers aren't bad but this info seems to be unavailable.

The control panel is a single unit with the cabled flow dampers and the speed control all in one, there aren't any definite speed slots or markings but the top cover is a pcb, there are around 7 (sorry it's been rebuilt and this is bit of a guess) small chips/processors on the pcb which I'm assuming are relevant to the various speed settings.

Any pointers would be much appreciated.

Post by **Peter.N.** » 18 Nov 2008, 00:09

If its the same blower unit as the Xantia, it has a two transistor regulator on the motor itself, these transistors are driven by the regulator PCB, they tend to go short or open circuit rusulting eventually in no fan operation. They are mounted on a metal bracket attached to the motor casing, you need to drill out a couple of rivits in each, unsolder the connections an fit the new ones using nuts an bolts. Suitable transistors are listed below my signature.

Clogzz · Post by **Clogzz** » 18 Nov 2008, 15:25

Welcome to our troubles, Simon.

It won’t be the ignition switch in this one.
Not sure about the Dispatch, but if the airflow is low at speed, you may have flow dampers not moving.
You should be able to see if the cables are moving the flaps from inside the all-in-one slider box.
Restricted airflow causes overheating of the resistors.
If the car has a pollen filter, it may still be the original one that’s turned a good black, and blocked by now.

Simonh04 · Post by **Simonh04** » 18 Nov 2008, 21:41

Thanks for the welcome & the reply Clogzz.
The cables and sliders move ok and heat used to move to the desired places but I'll check that they are moving at the cable ends just to make sure.
Not sure about a pollen filter being fitted but again worth investigating.
I did doubt by it's age that mine would be missing the relay mod at the ignition.
I'm thinking that this may take some serious concentration.

Cheers

Simonh04 · Post by **Simonh04** » 18 Nov 2008, 21:47

Thank Peter.N
It does have a sort of heat sink aluminium plate on the motor housing and it's likely that the transitors are there (on the reverse) out of view.
I shall look into that, your advice is much appreciated.

Cheers

Clogzz · Post by **Clogzz** » 19 Nov 2008, 11:23

If you have the transistorised blower, there is no resistor pack to regulate the speed.
Blower and transistor pictures:

Simonh04 · Post by **Simonh04** » 19 Nov 2008, 20:23

Thanks Clogzz, mine looks a little different to that in that the aluminiun part has spines or nipples if you like, probably just a variant on the heat sink idea.
The transistors aren't visible but could of course be on the reverse.
My question to you really is what's the nack in splitting the motor and blade away from the plastic case because I did look at that initially out of curiosity as much as anything else and it all seems pretty tight together.
Taking the fan blade off would give access but its pressed onto the shaft so tightly that it seems unlikely to budge and someone has warned me not try that approach.

Cheers

Clogzz · Post by **Clogzz** » 20 Nov 2008, 12:31

Hi Simon,

The recent vintage motors get parted from the casing by pushing in plastic lugs.
Some get accessed from around the outside, others trough the blades.
Trying to separate the blades from the shaft is indeed a risky job.

Pictures 9_5 and 9_17 on this Thai site that I can’t read

give an idea of where to explore:

http://www.citroenthai.org/diy/blower.html

I’ll try scabbing more relevant pictures from a French site, and post them if and when I find any.

Enjoy a good fiddle.

Post by **myglaren** » 20 Nov 2008, 17:12

Simon,
I saw one like that just last week and it may well still be for sale.
You would need to contact the seller direct and exchange photographs with him to be certain but it is definitely from an aircon Xantia, don't recall the year though.

I'll ask him if he still has it then PM his number to you.
Vehicle is located in County Durham.

Simonh04 · Post by **Simonh04** » 21 Nov 2008, 20:38

Hello all and thanks for your efforts and replies.
I have unfortunately had to bite the bullet and have bought a brand new fan through a good friend of who has his own small garage with a good discount structure at one of the major parts stockists.
I'm also going to admit that I didn't pay enough attention to the complete unit which does come apart quite easily, my previous experience of a 405 fan led me to assume otherwise.
Thanks in particular to Clogzz for the info and the link, I'm sure others will read this and be similarly appreciative.
A word of warning to others with the later models such as mine is that the heatsink with a surface similar to small cones or stalagmites is a sealed unit with no access to any components!
This is what has forced my hand into spending more money after visiting my friends garage. He has an old blower from a 405 which did spin albeit in reverse to the speed slider, slow was full and vice versa. That wouldn't have mattered but the case has the same shape but with mirror image fixing points meaning that it couldn't be secured.
Call me cynical but I think that they want us to buy new not repair things and are gradually making all parts throw away to promote their profits and shareholders dividends without regard for their customers.

Thanks again to all.

Post by **myglaren** » 21 Nov 2008, 21:07

Simonh04 wrote: Call me cynical but I think that they want us to buy new not repair things and are gradually making all parts throw away to promote their profits and shareholders dividends without regard for their customers.

Thanks again to all.

I'll let him know in case he is waiting for acall.

What you describe is `Value Engineering' and has its roots in TQM.

A statistical analysis of failure rates of various methods of constructing components leads to the ideal manufacturing process giving the best returns to the manufacturer and best value to the customer.

The idea is that a particular construction method will cost £x and will have the minimum failure rate so fewer failures = fewer returns/replacements and an overall lower replacement cost.

Bosch, as only one example, did a study of wiper motors and determined that a certain construction* gave the lowest manufacturing costs combined with the lowest failure rate, which translates for the customer that he pays the minimum for the part and it has the longest possible (statistical) useful life. If it fails it is cheaper to replace than to repair.

This premise does tend to fall flat on it's face when you bring competent DIY mechanics into the picture, but for the world in general, chuck it in the bin and bung a new one in is more cost effective for everyone concerned.

*which as it happens cannot be dismantled without destroying the damned thing