521 temp sender.... Common Datsun problem??

[Jocucumber]

i promise to update when i figure it out... i hate it when threads die 

[wayno]

With the ignition on, does that wire throw sparks when you drag it across a ground source?

Repeat when the engine is running, does it throw sparks and does the engine die?

Are all your fuses good?

[banzai510(hainz)]

If you can reach your hand up there wiggle the connector on back of the instrument panel around so maybe it makes a better connection.

 

I had this happen . I reseat the connecter and it fixed my charging(fuse popping issue). 

[HOGIE]

Well, what'l did you find? Bad fuse? Melted wires?

[Jocucumber]

I haven't had a chance to dig into yet... Im hoping this weekend I can get to it

[Jocucumber]

Ok took the cluster out and cleaned it a little and checked the gauge... replaced the cluster and grounded the wire at the sensor and the gauge works now, so I while I was replacing the thermostat I went ahead and put the old sensor back in and everything works now. I honestly don't know why it all works now or why it affected the starting when I installed the new sensor, but at least it all works

[DanielC]

The temp sensor body has to ground to the aluminium thermostat housing, to complete the circuit.  Different metals, when in contact with each other and water make corrosion. corrosion will eventually affect the electrical connection between the two different metals.   If the body of the sensor does not make electrical contact the engine. it basically is the same as pulling the wire off the sensor, and letting it hang there.