300M - no heat?

Not getting any heat on my '99 300M with 45000 miles on it.
All the blowers work well, but none of the buttons will give any heat....
only slight warmth.. Any help most appreciated..
Ralph Griffith

 

Check coolant level? Are the hoses going to the heater core warm? If
there is a bubble in the system, it would need to be purged.

 

Coolant level ok? Is this a 2.7 engine with the upper radiator connector
leaking at the bleed valve?

 

with the vehicle warm open the fuse panel and remove the fuse marked m10
it's the one the sits the highest of them all andlet it sit about ten
minutes then stick it bac in and run the vehicle and see what happens
this resets the hvac system and there is, was a issue with software from the
keyless mixing it up with the bcm
of course this is after you checked the coolant level

 

Max, your reputation is in question! Since when did a 300M come with a 2.7?

 

REPUTATION??? I tell you what, you answer that question for me ok, what yr
did they come out with the 2.7 in the 300m

 

300M in US has 3.5L engine

 

Yes i understand that, these post are not just in the USA, thats why I put
"IS THIS A 2.7"? There are a few people on here that like to pick at
things and try to make arguments out of them, thats not my style,

 

Uh...since they started manufacturing them for export?

Do I get the cookie?

--Geoff

 

U get the cookie, I think dead beat fell down and cant get back up...
someone call 911

 

I have had similar problems with my 99M.

Try this:
1. Start the engine but do not move the vehicle.
2. Set the Temp Control to 75 degrees.
3. Press and hold the Floor, Mix and Defrost buttons at the same time.
4. The control head will begin to blink and enter a diagnostic mode. Once
the unit has gone through its diagnostics it will either return to its
normal mode (with all air doors calibrated) or it will return one or more of
16 differend error codes between 23 and 51.

 

Thanks Bob ,, and thanks to others who replied... as previously suggested I
removed the fuse for 10 minutes and it may have worked - but this suggested
fix will be my 'Plan B'' All of you enjoy the Holidays - we have 6" of snow
and expecting 5" more.. will be white Christmas for my redheaded
grandkids..
Ralph
|I have had similar problems with my 99M.
|
| Try this:
| 1. Start the engine but do not move the vehicle.
| 2. Set the Temp Control to 75 degrees.
| 3. Press and hold the Floor, Mix and Defrost buttons at the same time.
| 4. The control head will begin to blink and enter a diagnostic mode. Once
| the unit has gone through its diagnostics it will either return to its
| normal mode (with all air doors calibrated) or it will return one or more
of
| 16 differend error codes between 23 and 51.
|
|
|
| | > Not getting any heat on my '99 300M with 45000 miles on it.
| > All the blowers work well, but none of the buttons will give any
heat....
| > only slight warmth.. Any help most appreciated..
| > Ralph Griffith
| >
| >
|
|

 

It usually happens to me at least once per winter with my '00 300M
that during sustained highway driving during moderate snow fall (or if
the highway is messy and throwing up snow) that my external
temperature reading will drift upwards (usually into the 50's ) and
soon after the vents will be blowing luke-warm to slightly cold to
moderately cold air, regardless of how high I set the desired temp.

Will I be able to perform the above-described diagnostic process
during an episode like this (ie while driving) ?