IPD sale Volvo Parts
XeMODeX - Experts in Volvo Electronics My Swedish Parts ad - genuine Volvo parts
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

'96 850 Heating and AC Problems

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

JonTechno
Posts: 6
Joined: Mon Jan 28, 2019 5:45 am
Year and Model: 1996 850 2.4L
Location: Charlotte, North Carolina
Has thanked: 8 times
Been thanked: 0
United States of America
JonTechno

'96 850 Heating and AC Problems

Post by JonTechno » Mon Jan 28, 2019 6:39 am

1996 Volvo 850 2.5L Automatic.

Heating and Air Conditioning unit stopped functioning over night. Oddly enough, if I press down hard on the Fan Speed Selector Switch, on Speed Setting 1 or 2 only, the Blower Motor turns on to blow out desired air temperature. But I have to keep the selector switch depressed. If I let go, it turns off. Fan speeds 3 and 4 don't activate no matter what I do.

Thinking I may have to replace the entire unit, but I wanted to first check here and make sure I've considered all the options.

Any suggestions appreciated



scot850
Posts: 5507
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 6 times
Been thanked: 135 times
Canada
scot850

Re: '96 850 Heating and AC Problems

Post by scot850 » Mon Jan 28, 2019 3:00 pm

Chances are the switch has gummed up or has failed. If you have the ECC unit it is easy to swap out if you get one from the junkyard. It may be a combo issue you may also have a power resistor issue too. If you have an MCC (it won't say Auto on the panel anywhere) then it may be the switch.

Neil.
These users thanked the author scot850 for the post:
JonTechno


2000 V70 R - still being an endless PITA
2006 XC70
2003 Toyota 4Runner V8 Limited
2015 Kia Sportage EX-L
1993 850 GLT -Sold
1998 V70 XC - Sold
1997 Volvo 850 SE NA - Went to niece in California - Sold
2000 V70 SE NA - New project and test bed - Sold

User avatar
BEJinFbk
Posts: 3635
Joined: Sat Jan 05, 2008 10:32 pm
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 20 times
Been thanked: 35 times
United States of America
BEJinFbk

Re: '96 850 Heating and AC Problems

Post by BEJinFbk » Mon Jan 28, 2019 7:16 pm

Speeds 1,2,3 & 4 indicate that you have MCC (Manual Climate Control).
I agree with Neil - Sounds like your fan speed control has packed it in...
These users thanked the author BEJinFbk for the post:
JonTechno


'98 V70 R - Well Equipped for Life Up North... ;)

Klausc
Posts: 772
Joined: Wed Oct 11, 2006 2:52 pm
Year and Model: 1995 855 Turbo
Location: Shorewood, MN
Has thanked: 4 times
Been thanked: 8 times
United States of America
Klausc

Re: '96 850 Heating and AC Problems

Post by Klausc » Tue Jan 29, 2019 11:35 am

Find a new unit at a junk yard or pick&pull. It might be possible to tear your unit apart and repair the switch, but that would take quite some time and I am sure you want heat tomorrow.
These users thanked the author Klausc for the post:
JonTechno


Klaus
If I had a larger garage, I could have more Volvos.

User avatar
BEJinFbk
Posts: 3635
Joined: Sat Jan 05, 2008 10:32 pm
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 20 times
Been thanked: 35 times
United States of America
BEJinFbk

Re: '96 850 Heating and AC Problems

Post by BEJinFbk » Tue Jan 29, 2019 1:06 pm

One could override the speed 4
full voltage relay to get heat for now.


'98 V70 R - Well Equipped for Life Up North... ;)

JonTechno
Posts: 6
Joined: Mon Jan 28, 2019 5:45 am
Year and Model: 1996 850 2.4L
Location: Charlotte, North Carolina
Has thanked: 8 times
Been thanked: 0
United States of America
JonTechno

Re: '96 850 Heating and AC Problems

Post by JonTechno » Tue Jan 29, 2019 1:08 pm

BEJinFbk wrote:
Tue Jan 29, 2019 1:06 pm
One could override the speed 4
full voltage relay to get heat for now.
How would one go about that?



User avatar
BEJinFbk
Posts: 3635
Joined: Sat Jan 05, 2008 10:32 pm
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 20 times
Been thanked: 35 times
United States of America
BEJinFbk

Re: '96 850 Heating and AC Problems

Post by BEJinFbk » Tue Jan 29, 2019 1:54 pm

The gist of it is that high speed (4) has
a relay at the blower motor that totally
bypasses the resistor pack and just puts
full voltage right to the blower motor.

Fortunately, this isn’t a new topic.
More info and further details can be found here:
viewtopic.php?f=1&t=86151&p=478938&hili ... ay#p478938

Stay Warm! :mrgreen:


'98 V70 R - Well Equipped for Life Up North... ;)

Cookeh
Posts: 60
Joined: Mon Jan 14, 2019 11:00 am
Year and Model: 1995 Volvo 850 T5
Location: East Midlands, UK
Has thanked: 13 times
Been thanked: 4 times
Wales
Cookeh

Re: '96 850 Heating and AC Problems

Post by Cookeh » Tue Jan 29, 2019 2:21 pm

Sounds like the resistor to me, as to my knowledge that's the only thing controlling blower motor speed is the resistor. These are easy enough to fit and pretty reasonably priced.

Here's a link to what is potentially the same problem by another poster on this forum:

click me



User avatar
BEJinFbk
Posts: 3635
Joined: Sat Jan 05, 2008 10:32 pm
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 20 times
Been thanked: 35 times
United States of America
BEJinFbk

Re: '96 850 Heating and AC Problems

Post by BEJinFbk » Tue Jan 29, 2019 7:59 pm

Cookeh wrote:
Tue Jan 29, 2019 2:21 pm
Sounds like the resistor to me, as to my knowledge that's the only thing controlling blower motor speed is the resistor. These are easy enough to fit and pretty reasonably priced.

Here's a link to what is potentially the same problem by another poster on this forum:

click me
Not true. If the MCC fan speed selector switch is bad,
power doesn't even make as far the resistor pack.
And from the description given by the OP, there's
something hinky going on with that switch.
It should crisply snap from position to position
with no additional wiggling or pressure involved.

Sure, the resistors may have also "reached the
end of their broadcast day", no doubt, but beginning
with that sketchy switch is the first move that I'd suggest.

It's all in the wiring diagram:
95 850 MCC Wiring Diagrams.pdf
(450.04 KiB) Downloaded 57 times
These users thanked the author BEJinFbk for the post:
Cookeh


'98 V70 R - Well Equipped for Life Up North... ;)

Cookeh
Posts: 60
Joined: Mon Jan 14, 2019 11:00 am
Year and Model: 1995 Volvo 850 T5
Location: East Midlands, UK
Has thanked: 13 times
Been thanked: 4 times
Wales
Cookeh

Re: '96 850 Heating and AC Problems

Post by Cookeh » Wed Jan 30, 2019 2:32 am

BEJinFbk wrote:
Tue Jan 29, 2019 7:59 pm
Not true. If the MCC fan speed selector switch is bad,
power doesn't even make as far the resistor pack.
Thanks, always good to learn!



Post Reply