Mercury Mariner 1994 40hp temperature switch

"Recently, when replacing the

"Recently, when replacing the water cover jacket, the temperature switch wire lead broke off so that all that I have to work with is a 1/4 inch "stub". I tried by pushing a wire connector on it but when engine is on, temperature warning goes off continously. Only remedy so far is to disconnect the wire entirely. Question is there a way to repair that switch by soldering a new wire to it? Engine s/n is 0G098654.

Thanks to all!

Ken"

"Ken, never heard of anyone so

"Ken, never heard of anyone soldering it, but you could give it a try. This (switch) sending unit works on simple resistance.

The switch is normally "open", at 190 degrees it closes, will give you the warning horn (if equipped) and will retard your timing through the TPM (timing protection module) which will limit your rpms to 2500 until the temp drops below 170 degrees (the point at which the switch will "open" again).

So you will have to try. I don't know if soldering will allow it to work properly or not.

If it works, you save 50 bucks on the cost of a new one. If it doesn't and creates "too much" resistance, then the horn will go off.

Alternately, if it doesn't work and remains open, you could cook your engine.

So I would test it after making the repair..."

Thank you for the reply. I am

Thank you for the reply. I am waiting on my service manual to arrive so I assume to replace it is to unthread it. That may be the wise thing to do.

Ken

"Ken I would remove it,solder

"Ken I would remove it,solder and test it in a pot of hot water and an ohms meter. For 50 bucks its worth a try. At least if it doesn't work you know you've made the right decision!"

"FYI: I removed the switch, c

"FYI: I removed the switch, cleaned it, soldered a new wire to it. Used an ohm meter and tested with the heat of the soldering gun. When cool, there was resistance and when hot, no resistance. Reinstalled and will test this weekend. I believe it will work.

Thanks for the good advice.

Ken"