I didn't have my first Volvo (1991 Auto Wagon with 168,500 miles) home more than an hour and I was already under the hood checking things out and already need help from the experts.

1. What, if anything, is supposed to be attached to the air box where this red vacuum plug is installed? Purpose?

2. Is this a vacuum line coming out of the firewall and is it supposed to be attached to the 90 degree pipe coming out of what I assume is a one way valve off the intake manifold? Purpose?

Thanks. I am coming from BMWs and Mercedes and will enjoying learning about Volvos.

 

welcome

in reply to your inquiries

1) nothing as far as i know
2) yes and yes - it supplies vacuum to the climate control system (if there are no leaks further upstream)

 

Thanks silvermine.

On the ride home yesterday in the pouring rain I did notice that I could not get the heat to come out of the defrost vents. Am I correct to assume that the 3 buttons, foot heat, defrost and recirculating, are controlled by vacuum? Something to take a good look at while I have the dash apart to replace the blower motor and resistor.

The other big issue I discovered was no running lights. I have headlights, brake lights, reverse and directional, but no running lights. Fuse maybe???

No instrument cluster lights either and the rheostat is missing. I did read that I can just short the two wires together and just do away with the dimmer altogether. I hope this works or could this be related to the no running lights issue? Would a bad light switch cause this?

 

You don't need to go tearing apart the dash just quite yet. Like silvermine said, that hose coming through the firewall is supposed to be connected to the nipple on the top of the intake manifold. It is the vacuum supplied by this line that controls the flappers that changes the flow of air to the various vents according to the three button control. Also, while you are fixing this, you might want to check the nipple on the intake manifold. The black/white plastic piece there is a check valve. Make sure that air flows one way (into the intake manifold). If not, the check valve needs replacement.

 

I was only saying that I could check everything as I will have the necessary dash/center console apart to replace the HVAC blower motor and the resistor.

 

when you have the dash apart, use a 'mityvac' hand pump with each of the bellow flap actuators, make sure it holds position. if it leaks and won't hold, replace it.

 

i guess this would be the one still on craigslist...

https://nh.craigslist.org/cto/d/1991...483110910.html

 

That's the one. Needs some cleaning, but runs like a charm. Drove it home two hours and not a single issue beside no defrost. I plugged that vacuum line in and now the defrost works as does the heat out of the center vent, but nothing out of the foot area.

I replaced fuse 15 and 16 and now my dash lights work (rheostat shorted together which I am fine with), heater control lights work, and all the taillights work as they should. I found a broken plate light holder that allowed the wires to short out on the body and probably blow the fuse. I ordered two new holders from FCPEuro.

Still need to diagnose the no foot heat issue though.

I like the simplicity of these Volvos so much that I have actually already thought about parting with my 122,000 mile mint Mercedes 300E to buy a four door 240.

 

300e's are a nightmare once they start going south

 

mercedes w124's are so much nicer than volvos, I now own 3 of them, and zero volvos.

just sayin'

 

I own two W124's and while they are nice and more luxurious than the 1991 wagon I just bought they are also much more complicated. I also enjoy the simplicity of my 1986 E30 BMW.

 

Your PVC/Flametrap should be #1 on things to ck/clean or fix when you purchase any B20 and up series of SOHC inline 4 cyl Volvo. If this is clogged, all your engine seals will weep/seep and you'll be doing allot of work that could of been avoided.


If/when you go into your dash for heater motor r & r, make sure you check all dash bulbs and replace those burnt out while there.

The recirc mode for you air is critical if you have A/C, keeps the condensor from freezing up in Hot Humid Conditions.