Auto Air Conditioning & Heater Repair: A/C - defrost odor, evaporator, rubber hose

Question
QUESTION: i notice an odor - almost electrical, or 'hot' when i turn on my 05 T&C defrost... not every time - 80% of the time. also notice same odor with air conditioner. local dealer has no idea.

ANSWER: HI Karen

Odors are usually one of four things.  If you are missing antifreeze then it could be a heater problem.  If you have had to add refringent then it could be your evaporator.  If non of the above then it could just mold in the evaporator case.  Lastly it could be electrical but that is not common and you would have had some accessory go out by now.  Let me know if you have done step one or two and I'll help.

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QUESTION: hi - have had no odor whatsoever with heat - been using it all winter (boston) without issues). started strictly with defrost in jan so I try not to use it - as a test, i have used the air a few times, and got the same odor - but NOT every time. I called the odor 'hot'... like the smell of a rubber hose that was wet... my dad thinks it smells electrical. of course i brought it to local dealer ASAP (in jan), though i (or they) couldn't recreate it (it was a sunny/dry day)... it seems strongest when it is actually raining - and wet out. i've just not used it frequently (defrost), but i expect to start to need the air conditioner as weather gets nicer... i almost went by the dealer today to show them, as it's very rainy, and it stinks - but had to get to work. found this website - hoped for some insight! thanks!

Answer
When you turn on the AC do you turn it on to recirculate or fresh air.  The reason I'm asking is that when you put it in defrost the outside air door opens your recirculate door does not activate and you may be smelling something form outside.  If you do use the recirculate with your A/C and still smell it.  Then you are closing the outside air door and it must be coming from the inside, but recirculate only works with the max air not defrost.  If I'm not being clear or you are not sure of what I am asking then you could call me at 305-468-8387. It will be easier to get all questions asked and answered.  Good luck let me know.