Sunquest pro 24 RS shuts down bulbs early

[kitzerz10]

I purchased this used last week. It runs great, but it shuts down about 7 minutes early. Fans run til the timer ends. Its a dial type timer. Anyone have ideas how to fix or what to look for, or how to bypass. Thanks

[Brian Oshman]

Probably a bad timer. Replace it.

[bosstan]

Its not the timer but the back up timer inside canopy if its shutting down early.

[Brian Oshman]

How so? The backup timer is solid state and not adjustable so it never changes the time limit, however, the twist timer is mechanical and is subject to wear and intermittent operation.

[carguy836]

My Pro 24 RS (made in 2000) does the same thing... turns lamps off early. How do I replace the timer? Where can I find parts and instructions? Thanks, Rich

[tantech1985]

yes the redundant timer can cause the unit to shut down early. take the orange and purple wires off the redundant timer. tape them together, and see if the unit runs the full 20 min. If it does run the full time, the redundant timer is bad. If is still shuts down early, the main timer is bad.

[carguy836]

Thanks, I'll try that. Looking at the bed, guess I need to remove the top cover to access the timer(s). Any precautions I need to watch?