Daf 105 experts?

I drive a 10 year old 105 and a few months back something went wrong with the heater and i could only get it to blow cold air. After several pleas and a couple of botch jobs the mechanics fit a new control valve. All went well but the control switch has gone slack again on cold .Not too bad in this weather but earlier morning and no sun its freezing Yesterday afternoon the mechanic removed a big part of the dash and forced the valve switch up half way to get some heat in. The switch cant be moved now so the window down when its hot window up and a coat when its cold. Any suggestions on why the control switch wont change the control valve position ?

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It can still be a problem on much newer DAFs, it is the control valve or occasionally the valve can be okay and the system has air in it.

The control valve works of a cable up position hot and down cold ,yoy can move it manualy withiut the cable but it is extremely stiff the valve is brand new virtually

Ramone, is the cable moving ok when detached from the valve, if it is then you know the stiffness is in the valve lever, you have already said you can move the valve lever manually without the cable and its stiff but have you actually removed the cable. Reason is if you move a valve lever with the cable attached at the valve end then you are also trying to move the whole length of the inner cable and the lever in the cab which will even with a working set up be harder to move then if done from the cab. Sounds to me there could be a problem with the cab control lever rather than at the valve end especially with you saying it is slack in the cold position which could mean when the lever is moved in the cab it isn’t moving the cable along its length. These problems are difficult to solve blind on the internet without seeing what’s going on. Sometimes obstructions under the dash can stop something operating yet when the dash is lifted the obstruction is freed and all looks ok until the dash is refitted, I’ve tended when coming across problems like this to look back at any history, has someone when the problem first showed itself done a ‘bodge’ job, sometimes just a misplaced cable tie or putting back the wrong panel screw/pin can make things work ok for a few times then its back to square one or worse. Under dash jobs are really a pain in the ■■■■ and only a Fitter that’s determined to get to the bottom of a fault will eventually sort it. Franky.

Thanks for the reply Franky , the heater valve has a small lever which in the up position is hot and down is cold , the lever is really stiff and the mechanic struggled to move it at all , he prised it to the middle position which took some doing. He then said he would look at it later which translated means put up with it . Graham mentioned it could be air locked so i might mention that but i doubt they will be interested. I was hoping someone had a quick fix

I know what you mean Ramone if the workshop staff have little interest, persuading them to sort a niggling fault is like pulling teeth, by what you say it may just be the valve it isn’t the first time I’ve fitted a new part and the problem has remained, you then go on another tack to find another faulty area then go in a full circle back to discover the new part was duff, extremely annoying and time consuming especially if the Gaffer is pushing to get the vehicle out the door and its usually the Gaffer rather than the Fitter that decides the driver can live with it. Like I say as long as the cable moves freely when detached from the valve then it must be the valve, the lever shouldn’t be hard to move. Hope you get it done before Winter arrives! Franky.

I’ve got a quick fix
Swan vesta

Sent while in furlough