znova

Has anyone typed up a clear diagram for how to connect the three wires on the z31 transistor to the 280zxt " l- " connector? Ive tried searching but am having trouble getting a clear answer.

Wide260z: Did you ever get the coil to fire without the use of the power transistor? I think my power transistor just bit the dust.

First let me say that this is only the second time I have had to actually start a new thread to try and get some clarification to the question i have. I have searched and found answers to just about every other question I've had, very impressive knowledge base hear. To the point, Ive got a 83zxt with about 135K miles on her. Been going through her cleaning up sensors, WIRE HARNESSES (as everyone instructs), TB, AFM, etc. The other day I changed the thermostat from a 160 to 180, mainly because its been quite chilly here and i was testing the pro comp mech. water gauge I installed to make sure the copper line was intact. Couple days later I notice water leaking out of what appeared to be the water pump housing. My searches have led me to understand that there is a small "weep hole" in the water pump and that when it begins to leak its a sign that the water pump is going or gone. The additional information that turned up in my searches was quite surprising; Things like: impellar blades in oil pan, water in oil, broken water pump bolts, etc... Can anyone explain what this hole on the water pump is and why its there?

Paz8 got it, jumped the wires and the fan blows with auto control set to heat. Thanks, as soon as I get my new heater valve the thing should blow warm - hot air, we'll see.

Would it be possible to bypass the "heater cock" (heater control unit) and run the coolant line directly to the heater core?

I have what sounds to be the same exact problem on my 83 zxt. I got my hands on the 83 zx shop manual and traced the problem back to (what the manual calls the "Heater Cock". I believe the term that is more readily used is "Heater Control Unit". It is vacuum operated and located under the dash, on the passenger side, near the center console. It controls the coolant coming from the engine compartment to the heater core. I managed to remove the one on my car and found that it was completely corroded. I have one on order and will let you know if this fixes the problem.