Is there another thermostat switch?

[ewaltb]

I have a 93 120 Force. I have replaced the thermostat that is housed above the cylinders. (The spring loaded one, 130 degrees) I have read posts that there is another one somewhere that should be located off of the hottest cylinder. Is there one? <br />I have looked verywhere for another, but am unable to locate it. I am assuming there needs to be one somewhere because something has to send the signal to the alarm. The one above the cylinders does not send any signal, correct? I am assuming since there is not wires or anything coming from the 130 degree one.<br />Thanks for any help.

 

[Reel Appeal]

Re: Is there another thermostat switch?

Hi,<br /> Usually there is only one thermostat per bank of cylinders.Ex.3 cylinder inline(1 thermostat)V-4 or V-6 motors usually two thermostats,etc.<br />The thermostat(s)usually do not send signal to the overheat alarm,but a temperature sender unit would.The sender is almost always screwed into the cylinder head(s),somtimes near the top.Should be a single wire comin out of a hex head(maybe tan or green in color?).If you have a V-4 there,check both banks for a single wire.There must be a removable sending unit on that motor somewhere.IF YOUR OVERHEAT ALARM IS SOUNDING THERE ARE A FEW CAUSES:<br />1.Bad water pump(not pumping/intermittent flow?if so,REPLACE IT)<br />2.Lack of oil in gas(correct mix/Is oil injection working?,do you see blue smoke at idle?)<br />3.Thermostat(s) stuck closed(or wrong thermostat)<br />4.Incorrect spark plugs(right plugs?)<br />5.Defective temp sending unit(on motor)<br />I'am NOT overly familiar with Force motors but this has been my experience.<br />Hope this narrows it down for you and good luck!

 

[Dan K]

Re: Is there another thermostat switch?

There is one thermostat only at the top of the head behind the thermostat housing. Overheat sensor is<br />located near 2nd cylinder from top on the cylinder head side. It's a small thermistor held in the block by a collapsible snap ring and has a single wire coming out of it.

 

[ewaltb]

Re: Is there another thermostat switch?

Thanks guys. I appreciate the advice.<br />Reel Appeal - Good advice. I have already changed all of the parts you mentioned. The temp sending unit is the part I think might be the problem. <br />Dan K - Thanks for the info. However, I thought the piece held into the block by the collapsable snap ring was the tacjh sending unit? I looked in the manual and followed the wire up to the dash, and it looks like it is the same. If that wire is the temp sending unit, where is the tach sending unit? Thanks again.

 

[Dan K]

Re: Is there another thermostat switch?

I own a 94 Bayliner with a 120 Force.Its doesn't have a tach. The tach is normally hard wired into the ignition coil circuit and doesnt require a sending unit.Try grounding the temperature sensor pigtail. The overheat alarm should sound.