WARNING-water temp alarm sender
 

Pissed at another merc foulup, well somewhat my fault too but at least partially their fault. Hurt an engine this weekend ( the no steering pump engine). The v-belt that drives the alternator (and also drives the circ pump) broke while I was at WOT dodging blowboats. First I knew there was a problem was when it drops 1000 rpm like I ran into something. Pulled back throttles and looked at guages, engine water temp gauge pegged. Shut it down and checked things out. Well I saw the broken belt, engine hotter than hell but the alarm never went off. Of course not, the thermostat housing where the alarm sender is mounted was nice and cool because the raw water pump was pumping just fine. Needless to say, Im moving the alarm sender down to the intake manifold with the guage sender. Damn silly place for merc to put the alarm sender.

Still trying to figure out how I broke a brand new (20 hrs) belt. Alternator and circ pump both turn OK, pulleys look fine. Anybody real good with charging systems using isolators and 3 battery banks?? My charging voltmeters are ok one minute and pegged the next. Both gauges, either both engines running or either one. Would that be a bad isolator? When they peg, the engine slows like there is a huge load on it. I wonder if thats what broke the belt.

Look for a burnt spot or damage to the belt. Does it look like it just got pulled apart. Man that sucks, :( Hope nothings hurt to bad. If you don't mind my asking what brand of belt was it.

That is one of the first things I did with my engines. I agree it is a stupid place to mount it.

Last year I lost my engine when a similar thing happen. The temp show 180 and the alarm was silent. My new engine has closed cooling. Where is the best place for the alarm and the temp probe? Currently my temp prob is on the bypass line and my alarm is the on the intake. I run block pressure on top of the t-stat housing. I know closed cooling is different. What is the theory on where these temps should be taken?

thanks

The belt was a NAPA. It looks lke it blew apart, no other signs of wear. Im replacing them all with Gaterbacks from Autozone ($20 a piece-ouch). Im putting the alarm sender in the unused hole on my intake manifold (the gauge sender uses the other hole).

Anybody with help on the charging problem?