posted by
someone claiming to be 960 Brickster
on
Sun Sep 27 13:03 CST 2009 [ RELATED]
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This evening I changed radio's in my 95 960, putting the factory original back in. I am not sure how this could be related, but after installing the radio, I no longer have any air coming from the vents. I checked the plugs on the climate control panel above the radio and all are fine. If i turn the fan on full I hear the blower, but noting comes out of the vents. This seems to be the same for defrost, foot, and all settings. Any idea what the heck happened here? I am getting frustrated with the endless litany of issues on the 960!
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Air path through the heater/AC is controlled by vacume, you may have kocked off a vacume line. Remove the passenger side knee bolster and you will see the vacume control unit.
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David Hunter
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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I think the cause is a major vacuum leak, possible in the engine compartment. I had the breather box replaced on Saturday, and there were lots of vacuum lines off and redone then. Plus I cleaned the IAC, flame trap. Runs fine, good idle, no codes. But nothing coming from the vents at all.
Today, I did an eyeball check on the IAC, pressure regulator, evap. egr, air pump, and the one hose that I can see from the breather box, on top. All seemed to be snug.
The only thing I did differently was use worm drive clamps on the intake instead of the Volvo band clamps. The local Volvo dealer does not carry the band in that size because the mechanics don't like them, and the Volvo guy I used put good quality worm drives clamps on instead. It may be possible that the breather box did not seat properly, but not sure how to check. He is a top notch mechanic, and I trust his judgement.
Assuming it is a major vacuum leak, what is the best and cheapest/easiest way to test for it? Smoke test?
Ideas appreciated here. The Volvo guy I took it to is 1.5 hour drive away. Not looking forward to a return trip.
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Have you followed dewfpo's instructions yet and isolated the leak to either inside the engine bay or inside the cabin. That would GREATLY simplify troubleshooting.
As he mentioned all vac going into the cabin has a check valve on it so that if you mess something up in the cabin, the engine is unaffected (not neccesarily the reason they did it, but it works). My GUESS based on limitted information is that a vac line got knocked off inside the cabin whilst doing the stereo work because:
You indicated that the guy who did the breather is a 1.5 hours away away so I suspect you would have noticed the lack of the vent operation by the time you go home.
With a 1.5 hour drive, you would have tripped a check engine light if there was a vac leak.
PLEASE give as much information in the first post as possible and not dole it out in bits and pieces. First you tell us you changed out the stereo. Then you tell us someone did lots of work in an area that has a crap-load of vac lines. Finally you tell us said individual is a long drive away so we have to assume you drove it back. All these tidbits and I do not see where you have the results from dewfpo's relatively simple diagnostic test. Troubleshoot should be a step-by-step orderly process. If you jump around, you miss things.
Onkel Udo
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Thanks for the post. I am working on it. I work full time, and had a work diner to go to so have not yet had a chance to try dewfpo's ideas. I have introduced the issues as I have tried to piece together what happened. As earlier, I took the kick panel off passenger side, but did not see the vacuum lines. Do I have to take the two bolts off the large black box the see the vacuum lines?
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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"Check the vacuum at the two vacuum hoses going into the firewall on the passenger's side. They both have check valves on them."
This one is the most important test and will take about 2 minutes and you can do without any tools.
"With the engine on, they should both show the same vacuum level on a gauge. With the engine off, if you pull the check valves off the lines going into the firewall, one will make no noise (this is the one going to the dome light sensor) and the other should hiss since you are dumping the vacuum. If this is the case, then your leak is on the dash side of the firewall. The one line goes to the 4 ball vacuum reservoir on the passengers' side, from there, the vacuum goes to the electronically controlled solenoid bank next to the reservoir that then distributes the vacuum to the specific vacuum bellows in the ducting via different colored vacuum hoses based on what your dash knobs are set to."
Once you have figure out if the vac issue is inside or outside the cabin it will be much easier to diagnose.
Onkel Udo
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Well, the vacuum riddle has been solved. I found a vacuum line that was undone at both ends. I followed the vacuum lines from the firewall until I found one that was off, which was tricky by flashlight. After I reconnected the end on the vacuum box under the throttle, I still had not air. So I followed it the other way and the vacuum connector was off the tree on the passenger side. Thanks to all who contributed.
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Thanks for the tip. Two questions.
First, are the vacuum connectors plainly visible going to the control unit?
Second, I had the oil breather box replaced over the weekend, and in the process cleaned the entire intake, flame trap, throttle body etc. Is there an engine compartment vacuum connector that could be the cause?
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Check the vacuum at the two vacuum hoses going into the firewall on the passenger's side. They both have check valves on them. With the engine on, they should both show the same vacuum level on a gauge. With the engine off, if you pull the check valves off the lines going into the firewall, one will make no noise (this is the one going to the dome light sensor) and the other should hiss since you are dumping the vacuum. If this is the case, then your leak is on the dash side of the firewall. The one line goes to the 4 ball vacuum reservoir on the passengers' side, from there, the vacuum goes to the electronically controlled solenoid bank next to the reservoir that then distributes the vacuum to the specific vacuum bellows in the ducting via different colored vacuum hoses based on what your dash knobs are set to.
DEWFPO
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1998 S90 083,228 and 1995 964 154,100
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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Thanks for the detailed suggestion list. I took the passenger kick panel off, and saw the black b ball. I am guessing I need to remove the two bolts to the large black box by the dome in order to see the vacuum lines themselves?
As in my other post today, I had put in a new breather box over the weekend, and wonder if the vacuum leak is in the engine compartment. Is it possible that pressure changes from this work forced a vacuum line off elsewhere?
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posted by
someone claiming to be
on
Wed Dec 31 18:00 CST 1969 [ RELATED]
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If you have a vacuum gauge, you can check for vacuum at the two lines I previously mentioned on the engine side of the firewall. If you have good and consistent vacuum in the two lines, then you can eliminate anything done in the engine compartment. Your focus would then be on the inside of the firewall.
You should be able to see the colored vacuum lines coming out of the solenoid control block to the left of the vacuum reservoir. Those colored lines go to each individual vacuum bellows.
The work you did in the engine compartment would disconnect a vacuum line in under the dash. Unless you knocked something loose in the dash during the radio swap (vacuum or electrical connector).
DEWFPO
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1998 S90 083,228 and 1995 964 154,100
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