Peugeot 406 STOP light flashing when a/c on

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jessko
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Peugeot 406 STOP light flashing when a/c on

Post by jessko »

Hello!

I was wondering, if anyone could help me with figuring out why my STOP light starts flashing when i turn on the air con.

I've read quite a bit on the topic, and i came to the conclusion its either faulty relay or one of the fan resistors. firstly i checked all conections and wiring and it seems to be ok. Relays seem ok, but i wouldnt know anyway, since i dunno how to check that. Then i checked the resistors, and although they're pretty rusted and coroded there is no open circuit. I disconnected the low speed resistor turned on the AC and the fan turned on for a few seconds and then turned off for a few, and so on. I just kepts turning on and of at very high speed.

Then i disconnected the high speed relay and left the low speed one. Again the fan turned on after a few secs of turning on the AC. But this time it never really stops... Its on for 15ish seconds and then it starts slowing down, but it starts again before it stops.

The STOP light seems to be flashing more often when the car is beeing driven than when its idling.

Now, with all that info, is there any definite answer to what may be diagnosis of the STOP light flashing when AC is on? Or if there is any additional tests i could do to be certain?

Really appreciate all the help, thanks!
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spider
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Re: Peugeot 406 STOP light flashing when a/c on

Post by spider »

The stop light flashing (I've seen a 306 do this) usually indicates an overheat or suspected overheat condition.

Does the internal temp gauge on the dash work properly ?

Do both fans actually work ? , a partially seized fan can cause this too.

It could be a faulty bitron sensor (usually brown) in the thermostat housing or less likely the bitron control unit itself, either up behind the dash passenger side or somewhere around the nearside area of the front bumper.

Someone with a diagnostics kit (Planet / Diagbox) may be able to determine the cause of this it may of well logged a fault code for it.
Andy.

91 205D-Turbo, gone but still missed
02 106D, TUD5B, gone but not really missed apart from the MPG
jessko
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Re: Peugeot 406 STOP light flashing when a/c on

Post by jessko »

Oh i forgot that part. Its a mk2 406, so it only has one fan. The flashing has nothing to do with actual temperature. It flashes when car is cold aswel. Temp gauge works fine and temp never goes over 90°. This only happens when the AC is on, if i turn it off everything works fine.
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spider
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Re: Peugeot 406 STOP light flashing when a/c on

Post by spider »

Oh I see.

You need ot see if any faults are logged then really, it may just be a pressure concern.
Andy.

91 205D-Turbo, gone but still missed
02 106D, TUD5B, gone but not really missed apart from the MPG
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