overheat alarm testing, '75 evinrudes

[pcrussell50]

i now own two 1975 evinrudes, a 135hp and a 50hp. just from reading various random posts here, i'm thinking these hombres have some kind of audible overheat warning system, and that it is associated with some kind of tan wire. couple of questions:

1] is the warning horn inside the engine cover, or somewhere in the control box?

2] is it probably the "tan" wire in both engines, since both are '75's? and if so, where generally do the begin and end? probably begin at or near a cylinder head, i'm guessing.

3] to test, i suppose, all i need to do is ground it, with the the battery hooked up and the ignition on?

-peter

 

[emdsapmgr]

Re: overheat alarm testing, '75 evinrudes

You are correct. Each head has a brown wire that goes to an overheat switch. The switch will (close) go to ground when the head reaches 212 degrees and will open when the temp gets back down to 175. The horn is in the control box and will sound steadily when either head sender goes to ground. The senders typcially have a black rubber boot over the knife connector by each head. If you move the boot on the wire, the knife connector is exposed. If you touch the connector to ground when the key switch is on, the horn should sound.