Hey guys, I just replaced the intake gasket and also replaced the water temperature sensor which wasn’t hooked up. Anyways I hooked it up to the new one and right away the water temp light comes on. haven’t looked at the wiring diagram yet but any ideas?
my water temp switch is normally open when cool, closed (shorted) when hot. So I'd guess you have a bad switch (sensor as you say) or you've installed what most call a sender which has variable resistance based upon temperature. You can check by testing resistance between the terminal on the switch (sensor) and ground with the connector removed. It should read open (megaohms + resistance) . If you read kohms, then you have the wrong unit. BTW I double checked and my temp light is off even when the engine is not running and ignition switch is on. Hopefully helpful and love '67s!
Hey thanks for reply. So i got this one like the pic I attached. I was thinking the the one green wire connector was a hotwire but looking at the diagram it just looks like it serves as a ground? I’m guessing the spring inside the switch closes the connection? I noticed it’s not on with the key in the on position. I did top off the coolant ,it was lower than I thought. Ill fire it up after everyone already awake and try again
The only way I was able to get out all air from my motor and radiator was to use a overflow/catch can. Milk jug half full next to the battery will work until you pick something nicer.
If when you disconnect the wire from the sensor the light goes off, then the wiring is ok. As you said the temp sensor switches ground. Even if the cooling system isn't full, the light shouldn't come on when you first cold start it.
Pull the wire and Ohm the sender touching the terminal and the body of the sender and see if it has continuity when cold. If it is open (no continuity) it is fine. If it is closed, it is bad or is the wrong sender in spite of the listing, as Boe stated. (thermocouple for a gauge, not a switch for a light)
Well shiznizzle. I unplug the wire and immediately the light went off. Tested the resistance and i’m getting resistance from the terminal to the body of the sender. Maybe its a dud. Can’t imagine why the circuit would be closed even at first start up. That’s the only parts that comes up for the 4.9 300. The weird thing is that wire was never used and was pinned under a valve cover. Anyway the only thing I can come up with its probably bad
Damn. Now that I’m looking at it I think I got the wrong one lol. The old one looks like this one pictured. I am an idiot. I was assuming The slight differences were modern upgrades . Oh well at least they’re cheap
