Pump not switching off

#1
I've read through a number of posts, and this seems to be a common problem but multiple possible causes.
I have a Jandy Aqualink RS4 that is about 16 years old.
I replaced the pump 3 weeks ago and now it won't cut off normally. I have to switch it on and off at the main breaker and have been doing this for 3 weeks. I hear a clicking sound when I switch from normal to service mode on the control panel. All the lights on the control panel and the inside panel work properly.
I also replaced the water temp sensor and wire since I thought that might be the problem, but was not.
I recall the pool guy saying he thought it was a relay, but I see some earlier posts that say it may be the breaker.
I did notice the breaker was half tripped before I replaced the pump. So before I spend $75 for a relay, I'd like to hear from others if it is likely the relay, the fuse(s), or something else.
 

JamesW

TFP Expert
Mar 2, 2011
12,819
#2
Probably the relay. If you get overcurrent, you can get a spark where the contacts meet and the contacts get arc welded together.