AC not working in '94 850 Turbo

Post by **hernhaw** » 03 Jun 2007, 19:21

Started the car this morning & smoke came out of air vents after turning on the AC. It was then followed by a funny burning-like smell & absolutely no power at all - not even blowing. The "REC" & "AUTO" lights both blink when I started the car again. It's running okay & no other warning lights come on so I assume it's safe to drive. I did notice several days ago that it was not as cold as it normally is but it was still working. My low coolant light also came on once last week but I don't know if it's related because we noticed a leak from a hose right after we bought it & it was already repaired.
When my 940 ran out of refrigerant, it still blew air-albeit warm air. Does the AC in the 850 shut off completely when you're low on refrigerant or should it be blowing warm air even so? Unless it's something more serious....
I was told (we bought it used) that an evaporator was replaced last year if that helps. I'd appreciate any suggestions you may have.
Thanks!

Post by **Ozark Lee** » 03 Jun 2007, 19:59

The smoke and burning smell is ominous but it may not be that bad. Pull the codes from socket B-1 and post them back.

With the codes we can likely figure it out.

...Lee

Post by **hernhaw** » 03 Jun 2007, 22:06

Thanks Lee...
I got a LOT of codes from B1. Funny thing is that I had a list of codes from Kelvin6 in his DTC Library but it jumps from A7 to B2- no B1 codes. Anyway here they are:
1-3-5
3-1-1
3-1-2
3-1-3
3-1-4
3-1-5
4-1-3
4-1-6
4-1-8
Is this possible?!! Or are these old codes mixed in? Sorry, I'm not up on this.

Post by **Ozark Lee** » 04 Jun 2007, 07:23

OK, here is what I get from the decoder ring.

1-3-5 No engine temp signal.
3-1-1 Drivers side damper motor shorted to ground or power.
3-1-2 Passengers side damper motor shorted to ground or power.
3-1-3 Ventilation damper motor shorted to ground or power.
3-1-4 Floor/Defrost damper motor shorted to ground or power.
3-1-5 Receirc damper motor shorted to ground or power.
4-1-3 Drivers side temp sensor fan, no control voltage.
4-1-6 Passengers side temp sensor fan, no control voltage.
4-1-8 No control signal to ECC power stage.

Often, when they throw every code in the book it comes back to a bad ground, the ground for the ECC is on the firewall near the steering column. The 3-1-X codes suggest that.

The 4-1-3 and 4-1-6 codes are a little more ominous and suggest that the ECC control head has a problem. The manual suggest clearing the codes and then see if those codes come back. If they do they suggest replacing the control head.

The 4-1-8 indicates a bad power stage which is the ECC's version of the blower resistor. When it goes bad the cabin blower does nothing. Was the blower noisy before? A bad blower is often the cause for a power stage failure.

Some detailed procedures are outlined in the manual.

https://www.matthewsvolvosite.com/downlo ... vo_850.zip

Once you download it see the file named ac heater system auto.pdf.

...Lee

Post by **hernhaw** » 04 Jun 2007, 22:30

Hi Lee,
Thanks for the manual info. I downloaded it & printed it out.
Well, I took it in to the shop & our mechanic removed the ECC control panel & found a short.
The panel reeked of the smell that came through the vents yesterday & one of the blk components on the circuit board was practically melted, thus the awful smell. I have his used panel while I am to look for one to replace it with. If I don't find one cheaper, he will sell me his for $350 but I just noticed that when I moved the fan lever (on the left side) to AUTO, it hardly blows air. I know that my original one blew strong when on AUTO, so much so that I hardly used it so it's not a big deal that this doesn't work like it should, but I hate to think that this may be an indication that the part won't hold up. I just pulled out the panel & everything seems well connected so I don't know what it could be. Is this part exclusively Volvo?
I cleared the codes but how long should I wait before I check the codes again-or is not necessary now the part has been replaced?
Thx for all your helpful suggestions.[/list]

Post by **Maxbaby** » 05 Jun 2007, 09:47

keep in mind that the ECC control panel is sold regularly on ebay at a lot less money than $350. I just quickly scanned and there's only one automatic unit this week but usually there's two or three.

I'm assuming you have the automatic controls...(there's two of the manual style on ebay right now too.)

Post by **hernhaw** » 06 Jun 2007, 22:37

Thanks Max,
I have seen that one on eBay but it's a little different from what I have. The fan lever is different- mines has the little fan icon on the right side I wasn't sure if I could use it. I seen the non-autos at such a reasonable price compared to the autos- I assume I can't use those right?
So far, I've only managed to find this part at Swedish Parts & Auto Parts People and it priced out around $600.
Is it at all possible it's more serious than just replacing the panel & it's causing it to short? My low coolant light reappeared but it's above the minimum line and I don't know if there's any connection to my AC problem. Another thing, with this current panel that's on loan, the air blows cold, but not REAL cold when it's on 60 degrees (max).
I'm afraid after spending that much money, there's a possibility it will happen again- which is why I want to return this unit back to my mechanic before something happens again.
Thanks, I appreciate any other suggestions....

Post by **Ozark Lee** » 07 Jun 2007, 09:01

I seen the non-autos at such a reasonable price compared to the autos- I assume I can't use those right?

No, not unless you change the entire system behind the dash. They are completely different animals.

I did a quick search on ebay and found this one.

http://cgi.ebay.com/ebaymotors/VOLVO-85 ... dZViewItem

...Lee

Post by **hernhaw** » 07 Jun 2007, 19:40

Thanks,
Do you know if the minor differences on the fan lever and the auto/off switch matter? Here's my unit...

Here's the one on eBay...

Degrees are in celsius (item from Canada). Do you think it's compatible w/the 850 turbo?

drew525 · Post by **drew525** » 07 Jun 2007, 20:03

I would think the one on ebay would be compatible with your car. It looks like it was pulled from an early 850 93-94, as Volvo added and changed some of the symbols on the ECC units in the later years.