aircon diagram

[Chris Hawes]

I am nearing the final push of my interior refit and would like to get to the bottom of why my driver footwell will only blow cold air.

Does anyone have idea on why I cannot allow heat to this spot?

I would like to check that the vacuum hoses are fitted to the mode switch in the right order. Does anyone have a better diagram to hand than that in the workshop manual?

[Chris Hawes]

Is there anyone on the list with a LHD DeLorean who happens to have their centre console out of the car at the moment?

I would like to talk about the routing of the hoses to and from the mode switch.

Thanks

[Chris Williams]

Damn,
Just finished putting it all back together today, would you believe it :?
Sorry Chris
Chris

[Chris Hawes]

Well I found out what the problem was with my aircon...

When I rebuilt the evaporator last year I placed the sponge back on the case as seen below:-



The glue had long gone so I did not know it was supposed to be glued on. As you turn the airflow up to the maximum setting, the air flow pushes the sponge back like a flap and despite some hot air coming out in the driver footwell it is more than cancelled out by the cold flow coming from behind the evaporator unit.

To see the hole that the sponge covers see below:-



So, I wonder why the design utilised so much foam in this area? The casing design could have enclosed up to the pipe work so much more closely giving less opportunity for an air leak.

The evaporator photos (kindly supplied by Dave Swingle) have helped remind me what it looks like back there (after all it is a year or more since I last saw it from that angle).

The best way to reach around to the rear of the evaporator is to press the brake pedal with your right hand which creates enough room for your straight left arm to disappear down the back of the evaporator assembly. WARNING the two pipes seen on the photo that pass through the sponge to the heater core get extremely hot once the car is up to temperature so please do this from cold!

A 'bodged' solution is to reach around the back and duct tape on the sponge. I opted for a more potentially permanent solution to escaping air by using 'Heavy Duty' velcro (purchased at my local Hobbycraft store) to provide a rigid heavy backing to the sponge to eliminate air from even trying to pass through the sponge.



The overspill of Velcro around the sponge perimeter is better than not enough as the actual areas for adhesion are limited. The tacky area over the hole or in the overspill area will simply dry out.



After all, for every bit of air escaping from here is having a loss of efficiency on flow to the vents.

The end result meant that my trip away this weekend in the car resulted in nicely toasted drivers feet and an overall hot interior when I wanted it. This is an easy problem to diagnose and the solution is low cost and effective albeit fiddly to apply. You will need patience and monkey arms to help the job to a quick successful result.

[stunned_monkey]

Had to fix this problem on several cars including my own. It's usually more noticable as a hot air leak in the driver's footwell. Throw that stupid piece of sponge away and use dynamat (I still ahve offcuts form when I did my car and it's great stuff :o)

[Chris Hawes]

Dynamat is expensive, heavy, thicker and is less efficient from an acoustic loss factor point of view:-

See the comparisons here between Dynamat Extreme and B-Quiet Ultimate:-
http://www.b-quiet.com/compare.html

The Vcomp with 2x layers would be the same thickness as the standard sound deadening found on the horizontal part of the fibreglass between the fuse panel and the ECU panel....

[stunned_monkey]

...and I could point you to articles saying the exact opposite..... but either way, It's been in my car for 4 years now and I'm happy...

[Chris Hawes]

I haven't heard of anyone complaining about Dynamat, except me of course

Lex is quiet................ and slow :wink:

[Tourettes Tony]

Best way i found was to cable tie the heater valve behind the r/h bank, that stops the hot water getting down to the matrix hence you can have sort of cool air going in and not hot air when its a really hot day. And if anyone has working air con it should be even cooler, or better still a 15mm iso valve in line so it can be turned off when required.

cheers Tony TT (Still tight)