Temp Sender Question(s)

[powbmps]

Trying to figure out why my temp gauge doesn't work. It's the style of thermostat with a alarm sender in one side and a temp sender in the other. Checking resistance with them out of the boat. The sender on the left is the alarm and reads zero ohms like it should.

The middle one is the one that was in the boat. Google shows it as a Datcon low range sender (100-240). It reads 960 ohms. The one on the right is a Sierra part I ordered recently. Supposedly it is the correct model for my motor. It reads 470 ohms. Could this be a problem?

Thanks!

[powbmps]

Answered my own question. The Sierra part I have is for a dual station setup. Need to be careful ordering on-line. I had multiple websites saying it was the right one for a single gauge setup.

[oldjeep]

Top end for a American temp sender should be 450 (470 close enough). The old one is likely shot, don't find anything that would be in the 900+ range new

[powbmps]

I think I figured out what was wrong with the original sender. I was reading from the threaded part to the threaded part. If I went to the tip area (that actually contacts the water) I was getting zero. There was so much rust on there it was blocking all the current. Sanded the rust off and I am getting 880 anywhere on the sender.

Oldjeep - can it cause problems using the 880 with a new thermostat?

[oldjeep]

I think I figured out what was wrong with the original sender. I was reading from the threaded part to the threaded part. If I went to the tip area (that actually contacts the water) I was getting zero. There was so much rust on there it was blocking all the current. Sanded the rust off and I am getting 880 anywhere on the sender.

Oldjeep - can it cause problems using the 880 with a new thermostat?

A thermostat isn't going to have anything to do with the temp sender working or not.

This is a thermostat - are you referring to something else?

This link shows a temp to ohms chart for the indmar stuff 880 would put you between 122-140F, so that doesn't seem right unless the chart doesn't apply for your sender/gauges. What year boat have you got and which engine?

https://www.bakesonline.com/detail.aspx?ID=1417

[powbmps]

Sorry to confuse the situation. It's a 160 thermostat, so the 880 does seem too high based on that Bakes chart . It's a 95 with the original Teleflex gauges.

[oldjeep]

Not sure if this will help, but has some troubleshooting and a chart showing senders for Teleflex gauges.

http://www.jamestowndistributors.com/userportal/document.do?docId=842&title=Teleflex+Troubleshooting+Water+Temperature+Gauges

[powbmps]

Thanks oldjeep. That actually is very helpful. It says that at 75 degrees, it should read 600 to 800 ohms. My office is only 63. Went for a drive with the heater set at 75 and now it's reading 700, so it seems to be okay.