Dead Heater Control Panel

Overbomber · Dec 17th, 2012, 13:49

While getting to the transistor and heat sink for the dreaded intermittent fan problem I appear to have shorted out the heater fan relay - sizzle of sparks and then the control panel is dead - no heated rear window, cabin recirculation or AC lights or control over them. Fuses look fine so I assume I've fried something within the circuitry or blown the fan relay? I don't have time to get too involved in testing too many components so a quick fix is required.
Any advice?
Cheers
Phil

gatos · Dec 17th, 2012, 16:07

I would double check the fuses and even try replacements. If fuses are fine, the probably heater control panel is shot. Take it apart and see if there are any scorch marks. I have a couple of control panels if you need one as well as fan relay if you want to try it

Overbomber · Dec 17th, 2012, 21:18

Thanks Alex, I have to admit it was dark and I had a head torch on so could have easily missed the fuse.
I'll get a chance to pull the dash apart on Thursday but I'll probably take you up on the offer of the relay and control panel just in case. I'll let you know by Friday,
Cheers
Phil

Volvoline · Dec 18th, 2012, 17:45

yea these are absolute crap in S40's... Motorola sucks

Went through 2 units in less than a year !

I still don't get when it's a Resistor problem and when it's a circuit board issue.

My problem is that if I put my fan on anything but Max (5) it will alter between that level, nothing and max completely randomly. Sometimes it will be stable on 2 for half an hour and then go crazy and shift do 5-2-5-2-5-2 like 20 times.

Resoldering the knob connectors helped for about a week and then it happened again. Any further soldering didn't change anything.

sebaveh · Dec 18th, 2012, 20:37

Changing the potentiometer will only help.
Like Gatos said - double check all fuses, then see the board on climate panel. Might be fried voltage regulator.

pierremcalpine · Dec 21st, 2012, 14:04

Have you tried resoldering each of the smaller connections on the CCM where the large green connector plugs in? Some posts have pointed to this being the issue vs. the solder joints on the POT itself. There is a good close-up pick on a posting that went up just recently in fact.

pierremcalpine · Dec 21st, 2012, 14:17

http://www.volvoforums.org.uk/showthread.php?t=146901

Dec 17th, 2012, 13:49	#1
Overbomber Junior Member Last Online: Apr 23rd, 2015 12:15 Join Date: Jan 2011 Location: Aberdeenshire	Dead Heater Control Panel While getting to the transistor and heat sink for the dreaded intermittent fan problem I appear to have shorted out the heater fan relay - sizzle of sparks and then the control panel is dead - no heated rear window, cabin recirculation or AC lights or control over them. Fuses look fine so I assume I've fried something within the circuitry or blown the fan relay? I don't have time to get too involved in testing too many components so a quick fix is required. Any advice? Cheers Phil

Dec 17th, 2012, 16:07	#2
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	I would double check the fuses and even try replacements. If fuses are fine, the probably heater control panel is shot. Take it apart and see if there are any scorch marks. I have a couple of control panels if you need one as well as fan relay if you want to try it __________________ Current car: 2002 S40 1.9D, 1992 240SE Nullius in Verba

Dec 17th, 2012, 21:18	#3
Overbomber Junior Member Last Online: Apr 23rd, 2015 12:15 Join Date: Jan 2011 Location: Aberdeenshire	Thanks Alex, I have to admit it was dark and I had a head torch on so could have easily missed the fuse. I'll get a chance to pull the dash apart on Thursday but I'll probably take you up on the offer of the relay and control panel just in case. I'll let you know by Friday, Cheers Phil

Dec 18th, 2012, 17:45	#4
Volvoline Master Member Last Online: Dec 31st, 2016 22:43 Join Date: May 2011 Location: JER	yea these are absolute crap in S40's... Motorola sucks Went through 2 units in less than a year ! I still don't get when it's a Resistor problem and when it's a circuit board issue. My problem is that if I put my fan on anything but Max (5) it will alter between that level, nothing and max completely randomly. Sometimes it will be stable on 2 for half an hour and then go crazy and shift do 5-2-5-2-5-2 like 20 times. Resoldering the knob connectors helped for about a week and then it happened again. Any further soldering didn't change anything.

Dec 18th, 2012, 20:37	#5
sebaveh Winegrover Last Online: Jul 17th, 2019 11:08 Join Date: Nov 2009 Location: Slovenska Bistrica	Changing the potentiometer will only help. Like Gatos said - double check all fuses, then see the board on climate panel. Might be fried voltage regulator.

Dec 21st, 2012, 14:04	#6
pierremcalpine Premier Member Last Online: Jan 3rd, 2024 14:43 Join Date: Feb 2012 Location: Toronto Canada	Have you tried resoldering each of the smaller connections on the CCM where the large green connector plugs in? Some posts have pointed to this being the issue vs. the solder joints on the POT itself. There is a good close-up pick on a posting that went up just recently in fact.

Dec 21st, 2012, 14:17	#7
pierremcalpine Premier Member Last Online: Jan 3rd, 2024 14:43 Join Date: Feb 2012 Location: Toronto Canada	http://www.volvoforums.org.uk/showthread.php?t=146901

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