96 rexhall dometic fridge shuts off

I was thinking connectors at one point...double checked my connections were in the correct position and then checked tightness and cleanliness.the connector is brand new as I replaced the coupler last fall to no avail..and now this year the board is brand new..i needed needle nose to pull the connectors off ..very tight fit..seem to recall last year with just replacing the coupler the fridge would light and within seconds ..shut off..this year with the addition of new board it stays lit for approx. 1 min..but shuts off everytime..no deviation..something is telling it to shut down..Has to be coupler no ? but its new and seems to test fine..1 thing i noticed was my meter read the millivolts in negative ..not sure its working right as it only momentarily read the dc voltage at the board..went from 12 volts to .439 volts...battery is a bit low..
Thx in adv
Peter