Compartmetn blower fan only has three speeds (fot four)

  • Thread starter Thread starter Byrocat
  • Start date Start date
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Byrocat

1994 Volvo 850.

When I push the blower speed control from to 4, I get air at varying speeds
until I get to "4", then nothing.

Up to about a month or so ago, I could get airflow (joking called "4" as the
"hurricane" speed.)

With the top speed gone, the others also seem to be reduced.

Question: what's gone? The blower motor or the dashboard control?

Thanks in advance!
 
I'd hazard a guess at the resistor pack that slows the fans down, if the
motor is spinning its not the motor (they either spin, or don't spin)... and
switches are pretty damn reliable components, but resistor packs (to slow
the motor down by reducing current) get hot, heat creates problems.

Since you say other speeds have been reduced since 4 has died, it makes it
ever more likely its in the resistor pack.
 
Rob Guenther said:
Since you say other speeds have been reduced since 4 has died, it makes it
ever more likely its in the resistor pack.
Click to expand...

Is there an on-line manual page that shows the part number and how to
replace it?

I have this horrible feeling that you have to pull the motor to change the
part (like the last two plugs in the V-8 Chevy Monza of days gone by --
owned the 6 but co-worker had the V-8 and decided that unless the plugs
totally blew, he wasn't about to change them....)

Thanks in advance!
 
Rob Guenther said:
I'd hazard a guess at the resistor pack that slows the fans down, if the
motor is spinning its not the motor (they either spin, or don't spin)... and
switches are pretty damn reliable components, but resistor packs (to slow
the motor down by reducing current) get hot, heat creates problems.

Since you say other speeds have been reduced since 4 has died, it makes it
ever more likely its in the resistor pack.
Click to expand...

I agree with Rob...*most* likely the reistor pack.... same symptoms occurred
in my 1993 850 GLT...and cured by replacing this little slab of resistors
(can't just do one...). I'd suggest, however, that you get it checked by
someone with a multi-tester BEFORE buyoing the $CDN 80.00 part, as the
second time it happened (at about 235,000km!), it was a (cheaper) relay
under the hood that had gone bad.......so I've got a *never* installed
resistor pack here I'd be glad to sell cheaply IF this is the fix you
need.... ;-)

Kevin
 
K Bourke said:
occurred
in my 1993 850 GLT...and cured by replacing this little slab of resistors
(can't just do one...). I'd suggest, however, that you get it checked by
someone with a multi-tester BEFORE buyoing the $CDN 80.00 part, as the
second time it happened (at about 235,000km!), it was a (cheaper) relay
under the hood that had gone bad.......so I've got a *never* installed
resistor pack here I'd be glad to sell cheaply IF this is the fix you
need.... ;-)

Kevin
Click to expand...


Thanks! I'll check the Chilton to see what can be done on my part to test
which is the dead party. A bum relay can give the same effect? I thought
that relay's either failed fuly open or closed, or am I falling victim to
cross-technology terminology (same term means completely different things,
depending upon what's being talked about. (EG, "bridge" as a structural
engineer versus dentistry is a classic example.)

I'll certainly keep you in mind if I do need the part. BTW, where are you
located? I'm Aurora, Ontario.
 
I don't know how to do it, nor do I have an online manual.

But as well as the Volvo, we have 2 VW Golfs; blower motor/resistor pack
failures are common on the older models of these cars, and since its
practically the same system (not really any way of doing it differently) the
symptoms are the same.... I'm in the VW newsgroup as much as I am in this
one, and resistor packs come up quite often - I think it's a bitch of a job
on a VW tho, I hope its easier on the Volvo, they tend to be laid out much
better.
 
Byrocat said:
Is there an on-line manual page that shows the part number and how to
replace it?

I have this horrible feeling that you have to pull the motor to change the
part (like the last two plugs in the V-8 Chevy Monza of days gone by --
owned the 6 but co-worker had the V-8 and decided that unless the plugs
totally blew, he wasn't about to change them....)

Thanks in advance!
Click to expand...

You seriously had to pull the motor? Was there a special tool the dealer had
to change the plugs?
 
James Sweet said:
news:[email protected]...
Click to expand...
[ ... ]
You seriously had to pull the motor? Was there a special tool the dealer had
to change the plugs?
Click to expand...

IIRC, it was necessary to unbolt the engine mounts and jack the
engine up a few inches--a _really_ poor design. There wasn't
enough clearance to get a wrench onto the plugs otherwise.

Might be part of the reason Monzas are virtually never seen these
days (besides being rust prone).

The plugs on my 145, on the other hand, are a breeze to change.


Gary
 
Byrocat said:
Thanks! I'll check the Chilton to see what can be done on my part to test
which is the dead party. A bum relay can give the same effect? I thought
that relay's either failed fuly open or closed, or am I falling victim to
cross-technology terminology (same term means completely different things,
depending upon what's being talked about. (EG, "bridge" as a structural
engineer versus dentistry is a classic example.)

I'll certainly keep you in mind if I do need the part. BTW, where are you
located? I'm Aurora, Ontario.
Click to expand...
Outside foggy Halifax.....LOL

As I had it essplained to me..... the first three fan speeds use lesser
resistances in a stepped-wise fashion to increase the fan speed...on the
850, the fourth speed is "straight through"...i.e.- no resistor in the
circuit. Here's the irony....you've got to replace the pack 'o resistors,
even though the broken speed doesn't *use* one... you can thank modular
electronic parts for that one!

As for ease of replacement...my local (ex-Volvo dealer) mechanic did it in
about 20 mins...I could be mistaken, but I thought this bit resides in the
centre console....?

Second time 'round for me, as I said, was some relay....about the same cost
for the part, and I *think* it's located on the side of the actual blower
motor housing...but again, don't quote me.

My (new) part is Volvo # 9137937 "Series Resista" in case ...

Best of Luck! How may km on your 850? A/C crapped out too?

K.
 
Rob said:
I don't know how to do it, nor do I have an online manual.

But as well as the Volvo, we have 2 VW Golfs; blower motor/resistor pack
failures are common on the older models of these cars, and since its
practically the same system (not really any way of doing it differently)
the symptoms are the same.... I'm in the VW newsgroup as much as I am in
this one, and resistor packs come up quite often - I think it's a bitch of
a job on a VW tho, I hope its easier on the Volvo, they tend to be laid
out much better.
Click to expand...

I don't know how similar the system is to a 740, but, on the 740, the
resistor pack is behind the glovebox fitted by two small screws into the
intake plenum of the heater, so that loads of cold and often damp air is
drawn over the coils, hopefully cooling them.

TTFN, Ken
 
Gary said:
IIRC, it was necessary to unbolt the engine mounts and jack the
engine up a few inches--a _really_ poor design. There wasn't
enough clearance to get a wrench onto the plugs otherwise.

Might be part of the reason Monzas are virtually never seen these
days (besides being rust prone).

The plugs on my 145, on the other hand, are a breeze to change.

Gary
Click to expand...

If your 145 had A/C, you'd need to unbolt the A/C compressor to get at
the first plug!

I remember spending several hours getting the plugs out of a Cadillac
Seville - the one with the funny trunk from the late '70s or early
'80s. There were various belt driven accessories blocking access to the
front plugs. And of course there's plenty of transverse mounted V6s
where the rear plugs are all hard to get at.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
Fortunately, I had the six-cylinder -- no problem chanignplugs, but
co-worker Bob had the 8-cylinder version. To get the wanna-go-really-fast
market, they shoe-horned an eight into the compartment.

Bob never changed the last two plugs, but did ahve to change the back end as
he blew it pulling away from a red light. Case of big engine, little
differential....
 
Quick update.

I got to the garage to swap out the old resistor block for the new one.

After an hour of digging out the knee panel, rummaging around and dragging
out the old block, then swapping in the new one, finding that nothing had
changed, then going over the whole fan controls from the fuse panel back to
the fan iself with the continuity tester, I was showing the problem -- the
selenoid/switch block that changes the resistor getting the voltage (and
thus controlling the fan speed) had a small melt-swelling on the bottom.

Opening it up and checking with the tester revealed that the selenoid had
cooked itself and had shorted out the last contact that was speed 4.

Got to go back to the garage (kudos to Suter's Garage in Aurora!) on Tueday
and have a very expensive part installed ($36.20Cdn).

Will also have them check to see if I have a dye leak from the A/C and give
me a quote on top-up versus repairs.

Hope everyone's weekend goes better than mine started off.
 
I have a similar problem on our'89 240 wagon.
1) Where is the selenoid/switch block which had a partial meltdown?
2) I was not able to find your earlier post(s) on this - I'd be
interested in the information there. Please repost or forward if
possible. Thanks.
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