Heater only blowing 32 degrees??

Technical questions and answers about the Mazda Bongo

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PGardham

Heater only blowing 32 degrees??

Post by PGardham » Wed Nov 14, 2012 5:48 pm

Hi there,

Recently joined the club and forum and looking forward to getting involved and next years Bongo Bash!!

I have a question for those that may know... The heater on my new shape Bongo has started blowing only hot air when the temp is set at 31 or 32 degrees, anything below is just ambiant temp air.
The problem first came to light when the Glow Plug light on the dash started to flash slowly. I pulled over and scratched my noggin for a momment then by chance I turned the heater OFF completely and then the Glow Plug light went out. The Air con wasn't in use and the vehicle had not long been up to running temperature.

Any ideas what this might be?

Seems to run fine and the temp is normal. Was gonna change the thermostat but that's a job I don't wanna take on if the problem is elsewhere.

Look forward to your thoughts :)

Paul.
South Gloucestershire
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Velocette
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Re: Heater only blowing 32 degrees??

Post by Velocette » Wed Nov 14, 2012 6:59 pm

I think setting it on 32 bypasses the sensor effectively switching the heater to hand if that helps. I would be checking the sensor connections, actuators and linkages, making sure the actuators move when you press the mode screen and temperature buttons. Mode flap actuator is drivers side and temperature actuator is passenger side.

I don't think it is likely to be the stat as from what I have read on here, the heaters have constant flow whatever the stat is doing.
[url]http://germanshepherdrescue.co.uk/[/url]
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g8dhe
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Re: Heater only blowing 32 degrees??

Post by g8dhe » Wed Nov 14, 2012 9:43 pm

Try the FAN control on the control panel (with the panel turned on), press it several times with a second or two in between until the display shows maximum speed, if it starts actually blowing on the highest setting then the transistor speed control module has blown, you can replace the transistor or get a new module from a breakers if that is the problem. Another thing to check is the plug on the rear of the unit it has been known to come loose.
Geoff
2001 Aero V6, AFT, full side conversion.
pleasure
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Re: Heater only blowing 32 degrees??

Post by pleasure » Thu Nov 15, 2012 8:39 am

I had the same problem - the interior temperature sensor was full of fluff.

There is a small grill in the dash just to the right of the glove box, behind this is the sensor.

One screw holds it on & a quick vacuum should cure your problem.

When you refit it check the fan works & air is blowing out of the back of it.
PGardham

Re: Heater only blowing 32 degrees??

Post by PGardham » Sat Nov 24, 2012 1:21 pm

Thank you kind folks :D

I'll try the suggestions and post the results.
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