Heater fan dosen't work...sometimes!

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sbj
Posts: 1
Joined: 31 Jan 2004 04:44 pm
Location: Denmark

Heater fan dosen't work...sometimes!

Post by sbj » 31 Jan 2004 05:01 pm

The heater fan don't
start. sm35 I can hear a click from a relay, when I turn the fan speed. It's dead for a couple of
days, and then it works again. What could be the problem ? A loose electric connection ?

User avatar
mgarageu
Posts: 133
Joined: 29 Dec 2003 07:15 pm
Location: Tartu, Estonia

heater fan

Post by mgarageu » 01 Feb 2004 10:43 am

you must check the resistor block near the fan
motor. there is a thermo-type fuse that can be rust and do not allow the fan to work.

Krishnan
Posts: 9
Joined: 30 Mar 2004 03:47 am
Location: Melbourne, Australia

Post by Krishnan » 31 Mar 2004 05:59 am

Hey Guys,
I have an 86 GLT and have the same problem. I can hear the Relay Click but
unfortunately no fan. I have checked the fan and know that works. Im at the stage where I'm
thinking of re-wiring the whole fan. I also looked for the resistor block but couldnt find anything.
Any help that can help fix this would be greatly appreciated.

Krishnan
Posts: 9
Joined: 30 Mar 2004 03:47 am
Location: Melbourne, Australia

Heater Fan Fix

Post by Krishnan » 26 May 2004 02:42 am

Depending on the year of your 300 there is a resistor either inside or outside the plastic fan housing. I have a 86 360 glt so mine was on the inside. Test it for continuity with a multimeter and see what happens. Chances are that it will be the resistor is stuffed (a common problem). Hope its of some help

Krish

360GL
Posts: 85
Joined: 04 Jan 2004 10:14 am
Location: Velenje

Post by 360GL » 26 Aug 2004 06:51 pm

I also have a fan problem and I'll post here.

The fan doesn't work at all.

The fan motor itself works when connected dirrectly to power source (battery), so it's probably OK.

There is voltage at the wire that connects to the fan motor.
There is good ground at the ground wire.

Both fan relays are OK.

When everything connected together the fan doesn't work.

What else should I check? I don't suspect the resistors because fan also doesn't work at full speed (which bypasses the resistors).

Car: 87 360 GL

Thanks for any suggestions.
87 360GL B200K

pettaw
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Post by pettaw » 27 Aug 2004 09:38 am

Unfortunately the fan current still has to pass through the resistor pack, even at full speed it still has to pass through the thermal cut off.

The resistor pack is inside the fan housing itself, and involves taking out the heater box assembly and springing the clips apart (careful you don't lose any!)

The resistor coils are usually fine, its the thermal cut out that gives trouble. There is a little springy bit that is designed to bend away and cut the circuit if the resistor wire gets too hot to prevent a fire, but they always rust and bend out of shape. We 'adjusted' ours by cleaning it and bending it back until contacts touched each other.

Andy

Juha
Posts: 43
Joined: 15 Jul 2004 01:54 pm
Location: Kerava, Finland

Post by Juha » 29 Aug 2004 10:48 am

I have a problem with the fan too. 3rd speed doesn't work. I've checked the fuse and the relay in the fuse box.
I've posted this problem somewhere else in this forum but I haven't found an answer yet. Is it the switch or maybe something else?
Winter is coming so help would be appreciated.

360GL
Posts: 85
Joined: 04 Jan 2004 10:14 am
Location: Velenje

Post by 360GL » 29 Aug 2004 12:55 pm

pettaw wrote:Unfortunately the fan current still has to pass through the resistor pack, even at full speed it still has to pass through the thermal cut off.

The resistor pack is inside the fan housing itself, and involves taking out the heater box assembly and springing the clips apart (careful you don't lose any!)

The resistor coils are usually fine, its the thermal cut out that gives trouble. There is a little springy bit that is designed to bend away and cut the circuit if the resistor wire gets too hot to prevent a fire, but they always rust and bend out of shape. We 'adjusted' ours by cleaning it and bending it back until contacts touched each other.

Andy
Thanks, I found the resistor pack. Everything is corroded / dirty / oxydized and I think the problem was that the thermal cutoff had poor contact and was heating up by itself and cut the circuit. I think I'll just replace the whole pack as it's in very poor condition. Any idea about the original part price? I'll ask the dealer tomorrow anyway.
87 360GL B200K

360GL
Posts: 85
Joined: 04 Jan 2004 10:14 am
Location: Velenje

Post by 360GL » 29 Aug 2004 01:08 pm

Juha wrote:I have a problem with the fan too. 3rd speed doesn't work. I've checked the fuse and the relay in the fuse box.
I've posted this problem somewhere else in this forum but I haven't found an answer yet. Is it the switch or maybe something else?
Winter is coming so help would be appreciated.
There are 2 relays for the 3rd speed. On is at the fuse box (D location), another is near the steering column (it has 1 yellow wire, 2 red wires and 2 brown ones - yours may be different depending on the year).

Also, speeds 1&2 use the fuse no. 19, speed 3 uses fuse 12.

If you'll be replacing any relays, pay attention to the pin locations.
87 360GL B200K

x19dude
Posts: 30
Joined: 06 Aug 2004 12:58 pm

Post by x19dude » 30 Aug 2004 09:50 am

Hi Guys,
I have the same problem as well - on an 84 340DL. I left the car up for about 2 years and the fan does'nt work at all now. I can also hear the relay clicking and when I click the fan on to max speed, the engine revs drop. Where is the resistor /heater fan under the dash and am I as well replacing the entire unit with another one (possibly risky if it comes from a scrap yard?!)
Thanks,
Paul.
340pw
1984 Volvo 340DL in family since new
1999 Subaru Impreza wrx Wagon
1991 Lancia Delta Integrale Evo
1977 Triumph Dolomite(Buried in a garage for the last 10 years)
1998 Alfa 156 Race Car.

pettaw
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Post by pettaw » 30 Aug 2004 10:40 am

All the info is in this post.
pettaw wrote:Unfortunately the fan current still has to pass through the resistor pack, even at full speed it still has to pass through the thermal cut off.

The resistor pack is inside the fan housing itself, and involves taking out the heater box assembly and springing the clips apart (careful you don't lose any!)

The resistor coils are usually fine, its the thermal cut out that gives trouble. There is a little springy bit that is designed to bend away and cut the circuit if the resistor wire gets too hot to prevent a fire, but they always rust and bend out of shape. We 'adjusted' ours by cleaning it and bending it back until contacts touched each other.

Andy

Juha
Posts: 43
Joined: 15 Jul 2004 01:54 pm
Location: Kerava, Finland

Post by Juha » 01 Sep 2004 08:30 pm

360GL wrote:
Juha wrote:I have a problem with the fan too. 3rd speed doesn't work. I've checked the fuse and the relay in the fuse box.
I've posted this problem somewhere else in this forum but I haven't found an answer yet. Is it the switch or maybe something else?
Winter is coming so help would be appreciated.
There are 2 relays for the 3rd speed. On is at the fuse box (D location), another is near the steering column (it has 1 yellow wire, 2 red wires and 2 brown ones - yours may be different depending on the year).

Also, speeds 1&2 use the fuse no. 19, speed 3 uses fuse 12.

If you'll be replacing any relays, pay attention to the pin locations.
Thank you. sm7
Man those relays are in a terrible place...

360GL
Posts: 85
Joined: 04 Jan 2004 10:14 am
Location: Velenje

Post by 360GL » 01 Sep 2004 10:03 pm

Just in case someone wants to know, the new resistor pack (for late models) costs 71 EUR at the dealer... a little expensive for 2 hairdryer springs! :D
87 360GL B200K

kaitsu
Posts: 2
Joined: 07 Sep 2004 07:58 pm
Location: Finland

Heater fan problem

Post by kaitsu » 07 Sep 2004 08:05 pm

Hi,

Same problem here. First time the problem was actually in the swithch. I just opened it, and cleaned. Then the fan worked again, in all positions. Now 1y later, nothing happens in any position, but just the relays.

Fan itself works, when powered directly from battery. So I just had enough, and made an extra connector (with fuseon wire) to get it work !

br,Kari

Juha
Posts: 43
Joined: 15 Jul 2004 01:54 pm
Location: Kerava, Finland

Post by Juha » 15 Sep 2004 07:36 am

I changed both relays and the fuse. 3rd speed is still mute.
So it has to be the switch?

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