Help-Volvo Temp Sensor Problems

[rwaterbury]

I've got a Volvo Penta I/O 5.7L engine with a temp sensor that is always reading <100 F by the gage and I doubt that the engine is reading this cool. When I measure the resistance of the sensor it is 550 ohm at room temp. Does anybody know if this is normal for this type of sensor. Also the voltage on the temp sensor wire is only 0.2V, it seems like this would be a higher voltage to get an accurate reading.

When I short the temp sensor wire to the engine block (ground) the gage does not change. Is it possible that the instrument panel ground wire is not connected? However all other gages do work.

 

[thrasher]

Re: Help-Volvo Temp Sensor Problems

If shorting the wire to ground does not make the temp gauge go to maximum temperature, then you have either a defective gauge or a wiring problem. The sender is not causing this problem, the sender may still be defective, but you need to check the gauge and wiring first. Once shorting the sender wire to ground gives you max temperature on the gauge, then you can see if the sender has a problem.

Gary

 

[Don S]

Re: Help-Volvo Temp Sensor Problems

When I short the temp sensor wire to the engine block (ground) the gage does not change. Is it possible that the instrument panel ground wire is not connected? However all other gages do work.

Anything is possible, but you have to LOOK at the gauge and CHECK the wiring with a meter to determine if it's the wiring or gauge.

 

[Byteme000]

Re: Help-Volvo Temp Sensor Problems

I have a similar problem with a boat I just bought. When I took it out the first time I noticed the temp gauge stayed on 100 deg. I grounded the wire and it went to full hot so I thought it was a bad sender. Being Saturday evening on a holiday weekend I wasn?t able to get a new sending unit. I went to an auto parts store and bought a mechanical temp gauge kit and installed it temporarily just for my own piece of mind. If you know what wire is the sender feed at the back of the gauge you could ground it to see if the gauge moves or check resistance of the wire from the gauge to the sender.

 

[Don S]

Re: Help-Volvo Temp Sensor Problems

Start a new thread with your question, even if it is the same problem as the original posters. This is his questions and answers.

 

[thrasher]

Re: Help-Volvo Temp Sensor Problems

Don, he isn't asking about a problem, he's stating what his problem was and giving a suggestion to try an external temperature sensor as he did..

Gary

 

[Don S]

Re: Help-Volvo Temp Sensor Problems

Oops, guess I didn't read the whole thing...... And I know better.
Sorry