samba-lee

Hi all,

What's this on my C2 varioram and how do I test whether it is working ok ? I presume it controls a flap which cuts off fresh air to the heating ? is this the thing that operated in when you reverse ? I guess it's a solenoid valve which controls vacuum to the vacuum diaphragm which pulls the lever of the flap ?

thanks in advance

Lee

IrocMan

The thing with a solenoid is indeed a valve that is activated (on/off) with a 12V signal.
The actuator on the right is simply activated using intake's vacuum. It pulls the rod when vacuum is applied.

It's pretty easy to test.
Valve : blow air in one of the pipes (use your mouth) it shouldn't pass (or the opposite). When applying 12V on the valve, state should change.
Actuator: if the valve does work, then this actuator needs a good hit of lubrication. These pieburg pieces are usually very strong and don't fail. It's just a matter of dust or rust that can be easily resolved.

Fergusond

observe position of arm exiting bottom of vacuum capsule, turn on ignition and the arm should be sucked into the capsule by about 6mm. Check the other two on top of the engine the same way.

samba-lee

Thanks, yeah, that makes sense. What does the pictures one do ? is it the one which shuts off when reversing ? and what do the other two do ?

thanks

Lee

samba-lee

Thanks, the other two up top activate when the ignition is turned on (then turn off when the engine starts - is this correct operation).

The one I pictured does not appear to do anything and I don't measure any voltage at the connector.

What does this one do ? and should activate when just the ignition is turned on ?

thanks

Lee

TheOtherEric

The point of these parts is to control a flap inside the plastic duct. I assume the flap closes when the engine is running so that pressurized air from the engine fan doesn’t simply blow out the air intake up above.

samba-lee

The solenoid valve appeared to be broken, so I replaced it with a new one #996-605-123-01 (Pelican website says it supersedes 993-605-123-00).

Now what happens is with ign on, nothing, but if I turn the heater control up then the rear blower starts and the solenoid activates causing the vacuum device to suck in and move the flap, and air is supplied to the heater box via the trumpet through the grill. Also when I select reverse gear the solenoid releases causing air to be supplied by the main engine cooling fan.

By all accounts this is the reverse of what should happen. ie the heaters are normally supplied by the main engine fan and the flap only activates to such in "clean" air from the trumpet when the car is in reverse and/or the temp on the duct gets high.

Has anyone seen this before? Is the solenoid somehow working or being controlled in reverse ? if so how could this be ?

thanks in advance.

Lee

brucec59

The action you see is correct. It keeps exhaust gasses from getting sucked into the heating system when you're going backwards.

TheOtherEric

THAT is the reason for this?!?! Good grief.

samba-lee

Thanks for keeping reading, but I think there is still some confusion (maybe on my part), but my car seems to be always taking in fresh air from the trumpet apart from when in reverse then from the main fan. Isn't this wrong or is it more complicated ? I definitely get a change of state when selecting reverse, but isn't it the wrong way round. i.e. when running, air for the heaters comes from the main fan, apart from when reverse is selected then the trumpet takes over.

I know the trump is also used when the air in the duct gets too hot but that's a different function.

The reason I question this is that the Adrian Streather book describes it opposite to the way mine functions and other owners also corroborate this. So I'm not questioning the reason for the function i.e. exhaust gasses, more that mine doesn't operate consistently with other documented desciptions...

Lee

brucec59

Exhaust gas is down low; the fresh air intake is up at the top at the grill. From Streather, p. 347:

"...when reverse gear is selected...The flapper valve moves to the open position cutting off the supply of engine air to the rear blower fan intake, replacing with outside air drawn in through the rear spoiler upper grill into the fresh air intake."

samba-lee

Exactley, and mine does the complete opposite - weird. Maybe my car doesn't like me and is trying the gas me.

There must be an explanation... is the solenoid for this different than the others ?

Lee

TheOtherEric

You can always just save a pound of weight (and complexity) and ditch the whole thing altogether, then install the 964 blower tube that the early 1995's used. Yes I'm being serious.

samba-lee

Thanks I know about the bypass tube. I'm just really very curious as to how it be functioning the wrong way round and I can't believe it's the only one in the world with this apparent fault...

Lee

helmet155

Mine actuates when moving the temp dial to red...

There is discussion that ditching it reduces engine cooling capacity as well...so I'm not sure it's the best thing to do.