I recently replaced the front blower motor resistor board on my 1995 Suburban. All speeds work fine, but on the two lowest speeds, I smell a toaster smell that is almost certainly coming from hot resistors. The smell seems to occur immediately on the slowest speed and after a few seconds on the second slowest speed. I'm trying to figure out which of the following scenarios is most likely and the best way to proceed:

  1. The smell is simply due to the fact that the part is new, and it will pass with time.
  2. The BWD resistor board is defective.
  3. The blower motor is drawing too much current, causing the lower resistors to heat up excessively, with the ultimate result of premature resistor failure and a possible fire hazard.
  4. The wiring is shorting and causing abnormal current draw.
  5. Some other problem somewhere in the electric system.

It seems to me that options 2, 4 and 5 are less likely because the smell occurs on precisely two settings, but I'd like to hear from others who have experience with issues like this. I'm also interested to know whether option 1 is at all likely, and whether option 3 is possible since I haven't blown any fuses. But my overall questions are:

A. Which scenarios are most likely?

B. Am I missing any other likely causes?

C. What is the most economical way to reach the true cause of this issue?

  • 1
    Measure the current draw to see if is within spec.
    – Solar Mike
    Jul 3, 2020 at 9:12
  • 1
    Since it is a new resistor there will be a burn in process, how long has it been doing this? The lower the speed setting the higher the resistance coil is used and the hotter it gets. They actually glow red hot.
    – Moab
    Jul 3, 2020 at 14:44
  • @Moab I noticed it as soon as I put the new resistor board in 2 days ago, so I haven't used the lower speeds for any extended period of time out of an abundance of caution.
    – SAG
    Jul 3, 2020 at 16:39
  • This is common for new resistors to burn in.
    – Moab
    Jul 3, 2020 at 17:57


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