How to re-calibrate heating with Vida

[yoda960]

Hi Chaps

The heating in my 2004 V70 with the all singing all dancing climate doesn't work. The fans all work, the sensor is fluff free, sensor wires intact.

It's not worked since I had the car, it might have blown a tiny bit warm, but now it's not warm in the slightest.

Could this be a knackered sensor, or could it need re-calibrating with Vida?

I'm not very familiar with Vida, anyone have any hints where to look?

Many thanks!

[Tomoose]

I'd be looking at the thermostat to be honest.

[yoda960]

But it gets up to temp quickly as it should, to halfway on the dash....

[capt jack]

Does the top hose get nice and hot? If so then the stat is probably OK.

Next thing to check would be the servo motor that moves the flap that lets hot air into the cabin.

If that's working then perhaps the heater matrix is either blocked or maybe isn't getting any hoy water from the radiator / engine block?

Jack

[davebb]

Hi Take the rad cap off , when the car is cold, then run it until car is up to running temp with the heater on, then refit the cap, as it may be a air blockage ,
Dave

[yoda960]

Thanks chaps, it's deffo not an air lock. The car has been the same since i bought it, and I have changed coolant too, flushed it several times before too. I doubt an airlock could be that stubborn.

Where is this servo motor located? How do I test it?

Thanks for the advice

Originally Posted by capt jack

Does the top hose get nice and hot? If so then the stat is probably OK.

Next thing to check would be the servo motor that moves the flap that lets hot air into the cabin.

If that's working then perhaps the heater matrix is either blocked or maybe isn't getting any hoy water from the radiator / engine block?

Jack

[Tomoose]

Have you traced the heater pipes to the bulkhead? I hope the heater matrix hasn't been bypassed! Probably not but it's worth checking.

[capt jack]

You'll probably need a Haynes to help locate the servo motor, but in general terms, ECC systems have the heater matrix full of hot coolant all the time, unlike older systems in which the heater matrix is opened by means of a heater valve.

The servo motor opens and closes a small flip which either opens or cuts off the supply of warm air from around the matrix into the cabin.

Cars with simple non-auto systems will usually also have Boden cables - a bit like bike brake cables - which opens and close the directional flaps, but on ECC cars these flaps are opened and closed by means of servo motors.

Get the engine running and up to temp, turn the fan off and make sure that things are as quiet as possible. The operate each of the heater controls in turn. If the servos are all working properly then you should be able to hear them. Sometimes you'll hear a gentle clicking noise - this suggests that the motor is working but that the flap itself is stuck.This can happen when either the drive cog on the motor, or the driven cog on the flap has shed a tooth.

On some car's it's possible to remove the motor and flap, strip it all down and then reposition the cog with the broken tooth in such a way as to "miss" the break.

I've certainly done this on a p1 V70.

I don't know how accessible are the heater servo motors on a P2, but it's not too difficult on a P1. Then again, a matrix swap is easy on a P1, but a dashboard-out job on a P2 I believe.

The other thing to check is that there isn't some sort of motor reset function. On some cars with electrically-operated goodies if the battery is disconnected then some of the motorised widgets need to be re-programmed. This is certainly true of the window lift motors on Saabs and Nissans!

I can't be more helpful that that, but hopefully if the stat is good, the inlet and outlet matrix pipework is hot, and there's no airlock then perhaps this will help you to narrow down the options.

Cheers

Jack

[capt jack]

PS: Sometimes the motor is called the heater blender.

[oragex]

Inside the engine bay, are the two hoses going into the firewall hot to the touch? If yes the heater core is getting hot coolant. Try then looking at the left side of the dash board (undo the grey plastic cover), there is a double arm with metal rods which opens/closes the heat. It should move.

Finally, good to know the heater core matrix does break on these cars: it won't leak but the plastic separator walls inside will fail causing the surface not to get hot when the fluid passes through.