warning light??

Good morning and thanks in advance for the help. Recently purchased a 92 ski natique that had not been used in a while and needs some repair, carb overhaul cleaning , interior etc. While running the boat yesterday noticed the temp gauge inop, quick check showed not connected this is the sending unit behind thermostat housing grounded the wire gauge reads full scale, someone has tried to replace it with an auto sending unit but even its wrong looks like a coolant fan unit has 2 spade connector, my real question is what is the other sending unit with tan or biege wire it appears to also connect to the oil pressure unit oil pressure works , guessing these go to idiot light somewhere but where??anyone have idea on gauge manufactuer or #for sending unit thanks again

thanks for the info will see what that does

Thanks for the help guys, have discovered a lot about the boat in last few days, also not real happy about the protec ign it works now but for how long???????Does anyone know if the conversion skidim sells uses the mallory magnetic pickup or unilite???? unilite was junk on the hot rods sure it is the same on boats   thanks again

thanks for the reply we had issues in hot rods with it maybe a new design by now will check with karen on it should the present system be replaced even though no issues with it, I know if it aint broke dont mess with it but ,,,,,,,,,,,,,,,,,,,,,,,

the cars just quit, replaced with msd or magnetic system never gave any more problems local hot rod dealer quit selling them for that reason they had warranty but that did you no good on the sid eof the road on sunday afternoon