Temp Sending Unit on '85 GM Mercruiser 181 I/O?

[jayhanig]

Does anybody know off the top of their head what size sending unit I need for my 1985 GM 181ci/3 liter engine? My temperature gauge was replaced over the winter but it appears to be dead. All of the other (all new) gauges are working. I'm assuming my temp gauge's sending unit is kaput.

I cranked it up today for the first time since it was winterized. After some initial problems with the choke not choking, I removed the spark arrester and manually flipped the choke to the closed position... got a great start then. I ran it for about 10 minutes at about 1500 repm... enough for the choke to completely open, yet the temp gauge sat on its cold peg.

FWIW, the gauge is a Faria Chesapeake which reads from 100-250?F.

 

[hungupthespikes]

Re: Temp Sending Unit on '85 GM Mercruiser 181 I/O?

You can look it up right here on Iboats.
Before you replace it try a jumper wire from the terminal on the sender to the engine block (ground it).
That will act like the motor is at 250 deg. Just put the jumper on and turn the key to the run position, that should peg the gauge.
If you have to replace the sending unit and use teflon tape remember to leave enough threads uncovered so the sending unit is grounded or it won't work.

http://www.iboats.com/Mercruiser-In...3619038--**********.291821891--view_id.270951

http://faria-instruments.com/site_manuals/IS0002F.pdf

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