Overheat alarm with dead gauge

[JMitch811]

I've had outboards forever but this is my 1st V drive. Outboards have an overheat alarm and I'm assuming a 2007 5.7 PCM will throw a code if it overheats. Here is my question. If my temp gauge is dead would an overheat alarm still sound in an overheat situation? All my other gauges work fine but the temp never moves. I changed the impeller today and it was toast. I haven't water tested it yet.
Any ideas of what else to try or to look for?? Thx

[s_kelley2000]

I am not sure if there is an audible alarm or not but it should at least trigger a warning light on the dash and it will put the boat in limp mode. I think there might be two temperature senders, one for the gauge and one for the alarm/limp mode. I could be wrong on that and mixing it up with the oil pressure senders which definitely have that configuration.

You said the impeller was toast when you changed it. Where any fins missing off it? If so they are probably stuck in the T-stat housing and sometimes transmission cooler. you will want to do a search for those because they could cause a blockage.