First - I had the Nissan dealer fix my AC compressor last year, and recently this year my AC stop being cold, again. The guys at the dealer checked it out and confirmed that the compressor was bad. The work was still warrantied, so I made an appt. to have them replace it.

I dropped my car off at the Nissan dealership yesterday to have the compressor replaced. The car had to be there an extra day because they couldn't finish yesterday.

I get a call today telling me that they mis-diagnosed the compressor, it was the "heater control unit". The service rep told me "my aftermarket stereo's wires caused the heater control unit's wires to bind", therefore making the "heater control unit" go bad. Then, and this ****es me off, they say they already replaced it, without first asking me, and the total is 313 and some change.

I don't even know what the "heater control unit" is, or if it's possible for my stereos wires to affect it. I talked to the guy who did my head unit and he said it doesn't sound feasible, but he does'nt know what the "heater control unit" is either.

I've been taking my car to this place for a while, but this seems kinda shady to me.

I am going to go by and talk to the technician that actually did the work on the heater control unit, and sask him exactly what was wrong, and ask to see the bad heater control unit with the binded wires.

Is this even possible, and what and where is my "heater control unit", I have a bad feeling about this.

 

Well, it's entirely possible for the stereo wires to bind the heater control unit. After all, it's mechanical. Oh, and what they are referring to (correct me someone if I'm wrong here) is the control mechanism for your heater. The part where you adjust the hot/cold settings. Behind that is mechanical, moving parts.

But then again, what do I know?

 

I was told by the service rep that the heater control unit (and I don't even think he knew what it was) controlled the defoggers, air/temp controls, and basically everything haveing to do with the AC and heater settings.

 

yeah... then we're talking about the same thing.

 

I can't see how it can make the electrical wires to "bind", I can see how it can make the mechanical ones to bind, like nubian said...
However, I doubt it would make the HCU go bad.... Because, if they really WERE bound, it would be difficult to move the slider back and forth... And THAT is purely mechanical, there is no electrical parts anywhere in hot/cold setting, it's just a cable that runs from the back of the unit, and it opens and closes the hot/cold vents...
I just shut my heat off (again) because I can't find a way to get the hot cable to connect properly without binding all to hell...
So I disconnected it from the HCU, pulled it all the way thru (Closing the vent) and just left it back there...
Now... My next question is.... How much AC... errr, fluid? is there in the whole thing?

 

The button that you slide from hot to cold was hard to move, but I never thought anything of it. I'm pretty sure it's been hard to move for a long time though, I still don't understand what my stereo wires have to do with that slider.

 

they're trying to pull the wool over your eyes. as has been said, there can't be any "binding" on the electrical wires, as they don't move.
unless they pinched and shorted some wires out during the stereo install, then that might be what they're talking about. that shouldn't cause the HCM to go bad though.

insist on seeing the parts, and exactly where they were located in the car before paying the bill.

When they're done trying to BS you, have the stereo guy talk to them. if you had it installed by someone else and THEY caused the wires to short, then it's their problem and their bill. not yours.

 

I talked with the service manager earlier, and figured everything out, the service rep didn' t know what he was talking about. Apparently, the stereo wires were in the way of the hot/cold lever ( which is why it was hard to slide before) making the HCU go bad over time.

Anyway - all is good now. My AC works like a champ again.

Thanks for the replies.