In this unit https://ameristarhvac.com/wp-content/uploads/pdf/M4AC3-Air-Conditioner-Installation-Manual.pdf

Can I replace the 35uF capacitor and the 6uF capacitor with a 35/5 dual capacitor? If so, how do I wire it up. Here is the wiring diagram: enter image description here

It looks to me like black on RC1 as well as black and orange on RC2 goes to common on the dual and yellow on RC1 goes to herm on the dual and brown on RC2 goes to fan on the dual? (I don’t have the optional RC3)

Note: this was a refurbished unit and I do not believe the capacitors are the originals so where would I check what the appropriate sizes are - I don’t see it in the manual and I don’t see 6uF easily available on amazon or commonly used on other ones, which is why I’m looking at 5uF on a dual

Here are the current capacitors:

enter image description here

enter image description here

And potential replacement: TEMCo Dual Run Capacitor RC0102-35/5 mfd 370 V 440 V VAC Volt 35+5 uf AC Electric Motor HVAC https://a.co/d/12kViAL

  • You sure you can't find them on Amazon? amazon.com/Motor-Capacitor-Round-Volt-12806/dp/B00C0YRSAO Note the original is rated 6uF 5% i.e. it's somewhere between 5.7 and 6.3uF. Your 5uF cap is not in that range. Will it work? Probably. But they don't rate these 5% for nothing - That's very tight tolerance for a capacitor.
    – Kyle B
    Jun 23, 2022 at 4:58

1 Answer 1


Based solely on the information you presented, yes, this capacitor is probably suitable. And your wiring is correct:

  • The Black L1 should connect to the common (looks to be unmarked) terminal of the dual run capacitor, which is bridged to the orange wire for the fan.
  • The HERM terminal should connect to the yellow wire labeled S on the compressor.
  • The FAN terminal should connect to the brown wire on the fan.

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