Hi,
My 99 E300's driver side blower blows warm air after about 30-40 mins of driving. The remaining center and passgenger side blowers continue to blow cold air.

Can anyone pls advice on what may be causing this warm air blower issue...?

Note: just above the rear view mirror, these is a cavity, some electrical sensor (i guess) fell off. Not sure what this cavity is for and if this is causing the warm air blower issue.
Thanks.

Look at these links, seem like there was one here too, can't seem to get some old links to work today, hope they are not gone forever. I'd do the self check first.

So here is an outside source.
http://www.continentalimports.com/ser_ic40142.html

Had a better link I thought, do a search here too.

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__________________
raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

The two biggest possibilities are a bad duovalve turning on the left-side heat, and a low refridgerant level. Probably the latter.

I had the same issue with my '98 about a year ago. The advice given in this forum was to have the refrigerant level checked. That was the issue. A couple of pounds later, good as new.

Pull your Fault and Actual Value codes per SteveBfl's article.

The data can be plugged in here to gain some insight for now.

Post data on forum for confirmation.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

My '98 also had a small refrigerant leak and had similar symptoms until two weeks ago when it all leaked out...now I am facing a new evaporator...dealer charges about $3500 and nobody else wants to tackle it so I guess I will DIY it (DIMyself, I guess is more appropriate).

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I had a similar problem with my 99e300td. Same symptoms but very intermittent and usually only when I "crossed" the temp range set on the climate control (like it was warm and then got cooler outside)

I ran the diags that were mentioned in the url and they revealed that a temp sensor under the dash was giving a bad reading. I replaced that sensor and the problem appears to have gone away.

See this url:

http://www.peachparts.com/shopforum/showthread.php?t=159998

I got the sensor from Phil (above) - cheaper than the dealer.