Nissan 240 SX SE ~ Heater Help

[Gravey]

I am unable to get the heater to work on a 1993 Nissan 240 SX SE - I can not locate the "heater water control valve" - According to the book it should be located at the firewall - I have spent HOURS trying to find it, and it can't be found. I've googled, I torn apart the car, and am at a loss - any secret compartments you know of?

thanks

[memphis180sx]

if its what i think it is a s13 dosent have it a s14 does though

[Gravey]

Well - despite your sarcasm, it certainly helps (somewhat) - since obviously I don't know nuthin' about these cars, except this heater isn't working, can you tell me how I find out if I have a S13 / S14? If it is a S13 - any suggestions on how to repair the heater?

[Jaescrub]

If you don't know if your car is a s13 or an s14 it's time to get into a dif car.

[Bubba]

I am almost sure he expressed no sarcasm in that response.

1989-94 year models are S13
1995-98 year models are S14

S14 has a valve in the engine compartment that controls the water flow through the heater core.
As far as I know, I have not found a valve like this on my S13.

Try checking all of your fuses. If that doesn't fix it then maybe changing out the climate control unit in the dash will help. Just takes a screw driver and a couple minutes to remove it.

[Gravey]

Okay Bubba - GREAT information - we obviously have a S13 - He has removed the climate control unit - checked all the fuses, put a whole new heater assembly, and changed out the climate control unit. Any other suggestions?

Thanks for helping us walk through this! <seriously>

[herbieS13]

is the heater core still good?

[Bubba]

I'm not a mechanic. That's just the first things I would check. Can't suggest much else seeing that the heater in my S13 seems to be some immortal spawn of satan. It blows air hot enough to warp trim pieces.

[brndck]

Ummmmm make sure the coolant hoses running through the firewall are attached and not looped. A heater is a very simple system. Hot coolant flows through a small radiator under the dash, a fan blows air across it, heated air flows through the ducts. ducts direct air to your face. Make sure that when you move the slider on the heater control unit that the cable on the back is making the blend door move accordingly. It's a mechanical cable and if the mounting points on either end aren't attached it won't be directing the hot air correctly.

And also, no, the s13 doesn't have a coolant valve or whatever.

[rcdad123]

take the trim around the radio and shifter out to get to the screws that hold the radio and the little compartment underneath it by prying it out. remove the four screws and slide the whole assembly out. on the left, you will find the cable housing that is connected to the temperature control slider. slide it left to right and see if the cable housing is attached properly. if it`s not, the temperature blender door will not move to make the temperature change. if that`s the case, you might have to secure it with zipties or glue it back into place. mine is loose, but i can have hot air blow thru, i just have to remove the radio to pull the cable housing so i can slide it all the way to cold. i live in SD, so i just don`t use the heater.

[Gravey]

The car is a type 13 the heater door seems to slide with heat control water is hot on top not hot at bottom at fire wall i am stumped

[rcdad123]

heater core is either clogged or you have an air pocket somewhere in the system. try bleeding the cooling system.

[brndck]

The car is a type 13 the heater door seems to slide with heat control water is hot on top not hot at bottom at fire wall i am stumped

Sounds like you have a clogged heater core then, or a blockage in one of the lines. Pull the core, make sure you can get flow through it, or if you can, pull the heater hoses off at the firewall and flush it out from there.