Thermoswitch Question

Kaykatz · Sep 18, 2013

I recently bought a Johnson 50hp outboard model 50esl71s. I just noticed that the wires from the thermoswitch are missing. I also noticed that someone put a small jumper wire on the terminal block. I removed that jumper wire and I can't remember which terminals it was connected to. Anyway, my power pack since blew & I have a new one on order.
My question: will leaving that jumper wire off effect the operation of the new power pack?
How will the system be affected having the thermoswitch disconnected?

Hope someone can help

Kaykatz · Sep 18, 2013

Re: Thermoswitch Question

I finally found a bit about it in my manual, it sounds the horn if the engine runs too hot.
Does this system affect the ignition system at all?

Daviet · Sep 18, 2013

Re: Thermoswitch Question

Not if you have a single wire temp sensor.
Some engines have both a single temp sender for the horn and a duel wire sensor for the S.L.O.W. mode.
What is your model number?

Kaykatz · Sep 18, 2013

Re: Thermoswitch Question

It's a 50ESL71S

Daviet · Sep 18, 2013

Re: Thermoswitch Question

OK, got a model number.
#23 is the temp switch for the "hot" horn. Test it by disconnecting the connector and touching the HARNESS end to ground with the key in the ON position, the horn in the control box should sound off.
#32 is the thermo switch. If the wires are bypassed on the junction block, I would get the system operational, it might save the engine for you.
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ

Kaykatz · Sep 18, 2013

Re: Thermoswitch Question

Thank you Daviet. I'll check the hot horn tomorrow. There are no wires at all on #32 thermo switch - they have been cut off right at the switch. That's what got me wondering if that little jumper wire on the junction box is supossed to fool the system saying that the switch is connected?

Daviet · Sep 18, 2013

Re: Thermoswitch Question

I don't have a manual for your engine, and don't think you are going to find one on line. Can you ask the orginal ower why the wires were cut.
There were some engines that used the thermal switch for a choke switch, does the choke work properly?

boobie · Sep 18, 2013

Re: Thermoswitch Question

The thermal switch was for the choke only. Don't worry about it. The temp switch is the important one.

Kaykatz · Sep 18, 2013

Re: Thermoswitch Question

I have the original manual.the choke is working fine.if the hot horn works wouldn't that tell me if there's an overheating problem? I just don't know if I need that little jumper wire.

Daviet · Sep 18, 2013

Re: Thermoswitch Question

If the choke is working properly and you tested the overheat horn and it works, test it using post#5, run it and enjoy it.

Kaykatz · Sep 19, 2013

Re: Thermoswitch Question

The horn goes off when I ground the temp switch wire to ground. How do you mean "test using post #5"? I should get my power pack in tomorrow, any ideas why someone would put that jumper wire on the terminal block? Am I ok to just leave it off? I just don't want to damage the new power pack.

Daviet · Sep 19, 2013

Re: Thermoswitch Question

I meant to test it just like you did.
I don't have a manual on your engine to look at the electrical system, but if it was running with the jumper installed I wold leave it there.
Maybe someone will chime in that has a manual and can tell you what the wires are for.

Kaykatz · Sep 19, 2013

Re: Thermoswitch Question

I take my hat off to you and boobie. Thanks guys. BTW, that jumper wire was not factory, someone just made it and I can't remember which posts it was attached to. Like you guys said, as long as the choke & hot horn are working, that jumper wire should have nothing to do with the ignition system. I'll find out once I get the new power pack installed.

Thermoswitch Question

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