on the vaccum can on my 87, I only have 3 ports, where as I have seen on older models, there are 4, where I dont have what appears to be the cruise control screw on plate. Just trying to figure out how to get my heat to turn off, as it is always going.

I include ZenArcher's pic to show what I dont have.



Thanks ZenArcher

 

I have the exact same problem. Go post on http://www.nissanforums.com/ there a whole lot more helpful.

 

On my '88 model, the one labeled through firewall, controls the heater, vent, and a/c. If that hose is cracked anywhere you lose those controls and the heat runs all the time. I found my crack behind the radio-center control area where there is a split in this hose. Not too hard getting counsol out, just have to put on e-brake and shift to 1st if it's an auto.

 

start by replacing all the vacuum lines in the engine bay