Been lurking here for a few years.. did a search and didn't really find the same problem.

A few months ago I had Midas put my 3rd radiator in the Z. The Midas tech told me that there is some electrical issue causing my fans to never shut off.

The fan never shuts off, even with the keys out of the ignition. Only time it shuts off is if I disconnect the battery, or disconnect the power cables directly to the two fans.

I attempted my own fix, and replaced a relay in the fusible link and relay box right in front of the battery. It took me months to find this part, dealers were clueless, but I finally managed to get one. Replaced it, same issue, no luck.

Just brought it to the Nissan Dealer this week and they're saying its the IPDM box, and its going to run me 1000 to replace. Then the dealer stated after the box is replaced, if its still not turning off the cooling fan, they'll have to do a total wire by wire check of the system.

Does this sound right at all? 1000 bucks just to "maybe" fix a fan that won't shut off?

 

Stay away from the dealer. This "let's replace a part for $1K and see if it holds" crap is a lot of BS. Go to a reputable garage that has a bi-directional scan tool like a Snap-On Verus, Modis or whatever that's good at checking for shorts and bad grounds. If you really do need to replace your entire master fuse panel, then buy one from a junkyard. It'll cost you about $900 less than a new one.

 

Also looked more into the paperwork they gave me.. states Multiple Codes in System, P1065 ECM Back up circuit, P1610 Lock Mode, P1615 Difference of Key, C1130 ABS Engine Signal 1, traced to Intelligent Power Distribution Module.

I did find a pretty reputable performance shop that likes to turbo out Z's so.. getting a second opinion from them on Monday.

 

How long have you owned the car, has it been wrecked?