Originally Posted by skipmac
Apparently even if the voltage looks good, on compressor startup the initial draw can knock down the supply voltage low enough to cause a problem. Since the drop happens so quickly it may not be apparent on a standard digital volt meter. Could be just a little corrosion
or a loose connection in the existing wiring.
Before doing anything more expensive I would try running a temporary, large gauge wire direct a fully charged battery to see if that solves the problem.
If I had a dollar for every time I danced this dance...it goes something like this during a phone
Client: Hi Rich, the unit tries to start but trips off and I get 3 error lights so I need to buy a new controller.
Rich: Hold on a bit, what tests have you done to know the controller need to be replaced?
Client: A friend came by and looked at the unit and told me the controller is dead.
Rich: Did your friend do any tests or does he have any refrigeration experience?
Client: No, but he stayed at a Holiday Inn last night…
Rich: Ok, well before we throw money at the problem in a WAG (Wild Ass Guess) approach, let’s do a few easy tests to make sure you really need a new controller. Run a temporary Positive and Negative wire directly to the refrigeration unit to the positive and negative battery terminals and tell me what happens.
Client: That’s hard for me to do and besides I’ve checked the voltage with my harbor freight volt meter and I have 12.5v at the refrigeration unit so voltage can’t be the problem.
Rich: The electronic controller is more sensitive than your volt meter and voltage issues that don’t appear on your meter can still cause the controller to trip off and go into the famous 3-flash error mode.
Client: Are just BS-ing me Rich and trying to blame the problem on my boat rather than your system? This boat’s electrical system
passed the survey
and is Cherry, I mean like eat out of the Bilge
Cherry. I can’t believe there is a voltage problem on my boat.
Rich: Well I can sell you a new controller and ship it out today, but until we do some simple tests you could be wasting your money and it may not solve the problem, so what do you want to do?
Client: Well it sounds crazy to me but I’ll try it and get back to you.
Rich: Just give me a call with the test results and we can take it from there.
Client the next day: Hey Rich, I can’t believe it. I ran the wires and it worked and pulled down the ice box last night. I now have ice cold beer
, thanks for you help.
I go through this dance almost weekly and no one wants to believe the voltage issue/problem but iit is FAR MORE common for the 3 flash light error signal to be a voltage problem rather than a dead controller. While working with a boat in Spain
that was recovering from a lightning
strike the system would run from their starting bank but NOT from their house bank. After some testing the client determined that one of his batteries had a damaged cell and once that battery was taken out of the bank the system ran great. The only way we figured this out is that he had two complete systems (fridge and freezer) and they were wired to the different battery bank one was working and one wasn't. Lose grounds, corrosion, we have seen it all. With a 5 year warranty on the system we have pretty darn good records on the controllers going back years and years and there are plenty of good controllers tossed in the trash every year by people and “refrigeration tech” playing part-swap out troubleshooting with the clients money.