Troubleshooting Forest River 5th Wheel AC Making Zapping Nosies

Updated 01/27/2026 | Published 08/23/2024

Question:

Hi my 5th wheel key stone forested river AC unit is making zapping nosies

asked by: Mona S

Expert Reply:

Hi Mona; if your AC is making zapping noises that probably isn't a good sign. Then again, I'm not sure to what extent this is happening. It could be any number of things causing this, and perhaps not even something electrical that just sounds like a zap sound if there is some kind of vibration.

I would try to look up in your air distribution box or under the shroud and see if anything is visibly happening that would cause this. You can also double check the wires running to the AC and controller to make sure nothing has a loose connection or short. If this isn't something you're comfortable with I would take it to a local shop and have them check it out.

If it is the unit itself then you could potentially replace it with the # ACM135 you were looking at depending on your setup. However, if it is an issue with the wiring, controller, or air distribution box a replacement AC would not solve the problem.

expert reply by: Robin H

Robin H.

1/27/2026

Hey Mona, what ended up happening with the AC on your 5th wheel after you checked for loose wires or vibration issues? Knowing what you found could really help others dealing with the same kind of noise.