Temp Gauge on a Flybridge

"Hi Guys,

As an owner of a

"Hi Guys,

As an owner of a Bertie 25 with 470 Mercruisers I have been interested in various forums that talk about the motors running hot. This has not been a problem so far for me, however, as I do most of the driving on the flybridge and there is not a temp gauge there, my question is: Is it difficult to have one installed for each of the motors on the flybridge dash so that I may monitor the temps of my motors. Thanks in advance for your input."

Connect a set of gauges for th

Connect a set of gauges for the engines by wiring each gauge separately in parallel with the existing gauges. Use 16 gauge wires the same colors helps in future trouble shooting.

"Speaking of temperature gauge

"Speaking of temperature gauges, mine has stopped working... sort of. It worked fine before putting it up last winter usually registering around 160 degrees F.
My engine uses sea water to cool.
The gauge is not registering anything. Or at least I thought. I had a buddy watch the gauge as I disconnected and re-connected the wire from the temperature sending unit. The needle just barely moved up. But it did move ever so slightly.
I replaced the sending unit, no change. The wiring looks fine. To pull the dash unit off to get to the gauge looks like it would be a bear but because the needle does move a little, I don't think its the gauge itself.
Could it be that the thermostat is stuck open thus not letting the water get up to temperature? The hoses do not appear to get warm after running the engine. Water temp here in Baltimore is still in the 50's."

"Leonard,
Buy yourself a hand

"Leonard,
Buy yourself a hand-held infra-red thermometer. You can usually get one for less than $50. Just point it at what you want to know the temperature of. It makes troubleshooting these kinds of problems a whole lot easier and will help prove or disprove a cooling system problem.
It does sound like your engine isn't heating up, but not knowing for sure which hoses your are refering to, it makes it kinda tough to say.
Pulling the T-stat out and taking a look isn't very intrusive so that would be time well spent."

"Leonard Stielper
When you ta

"Leonard Stielper
When you take the wire off the sender, touch it to a good ground and see if it pegs over to hot. If it does it shows the gauge in Ok.
Bert"

"Could it be that the ther

"Could it be that the thermostat is stuck open thus not letting the water get up to temperature?"

Yes; replace it.

"Thanks guys.

If I put an m

"Thanks guys.

If I put an multimeter on the temperature sending unit, what reading should I get if its good?"

"BATJ:

Ice cold about 2,000

"BATJ:

Ice cold about 2,000 ohms
Overheated about 200 ohms

Test it on the engine; remove wire and attach ground probe to sender base or engine ground and positive lead to center stud. Start the engine and watch the ohms start to drop as it warms up."

"Do I remember reading somewhe

"Do I remember reading somewhere that if you are running two temp gauges or two pressure gauges in parallel off the same engine, that you need a different range sender?

Rod"

I know with my crusader engine

I know with my crusader engines they require a different temp sender for dual stations.

"Learn something new every day

"Learn something new every day. "

"Okay... it was the thermostat

"Okay... it was the thermostat. Replaced it today and after a warm-up period, the gauge came right up to temperature as it did previously. The thermostat was fairly corroded and stuck open as suspected.
Thanks for everyone's input."