high temp alarm

[te102056]

I was low on fluid in one engine. The high temp alarm came on, I turned the engine off and let it cool, added fluid and started the engine. The high temp alarm stays on constantly now with the temps at low temperature. Is it possible that the sensor has gone bad? Or does this alarm also indicate another problem?
Please help asap.
Thanks
Tom Erwin

[DougSea]

Which engines do you have Tom? If they're Ford Lehman's I'm sure Jay will chime in with some good info.

[jleonard]

Is it a Ford-Lehman? The low oil and high temp alrms/senders are on the same circuit. When they are closed (or when one of the leads touches engine ground ) the alarm sounds. So you need to check the senders to make sure the wires are connected/not shorted.
After that , yes the senders can go bad, you'll have to check them. The oil pressure alram switch is normally closed and it open when the pressure comes up (either 15 or 20 psi). The temp switch is normally open and closes when too hot (not sure of the temp, guessing 205 F).

FordLehmanEngineElectricSchematic.pdf

[te102056]

I have ford lehmans
Thanks
Tom

[brookesmith]

Just recently changed oil sender and temperature sender and gauges. American Diesel has the lehman replacements and kind of recommends changing the gauges and sending units.. Very reasonable for dual gauges. Not sure if the same sensor is used for the alarm. Pretty sure that is a separate temp sensor that the alarm works off of. Might check that out tomorrow..