7MGFORCE Posted January 26, 2010 Share Posted January 26, 2010 So I got my car running with a carb v8 so most engine wiring are gone. I tried using my heater today but when I put it on heat the thing does not even blow any air. If I put the temp on cold it blows cold air. Is there a switch to activate the hot air fan? I just flushed the heater core and it's not clog. I got this shell as a non working so I don't know if it had work before the swap. Any ideas on what wiring of switch to check? Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 26, 2010 Share Posted January 26, 2010 On my 260 (with oem air con) I don't think there is a switch that would turn on the hot air vs the cold air. If you turn the fan switch all the way to the right, it should be blowing , no matter what the temp control switch is set to. Are you saying if you have the temp control switch on cold, the fan will blow, but if you slide the temp control to hot, the fan turns off? If that's happening, I'm totally lost. If the fan blows while the temp control is on hot or cold, that's normal to me. If your prob is not the fan, but just hot air vs cold air, then you may need to start checking your vacuum lines. that's what controls the heat being able to enter the cabin. That's of course if your getting hot water to the core, for the fan to blow thru. Remove the control panel in the dash and look behind it. There are several vacuum lines that hook to the selectors. Then trace them to where they go and see if any are missing/cracked etc. Good luck! Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted January 26, 2010 Author Share Posted January 26, 2010 I'm talking about the top selector on the temp control. When it's on the cold side the fan blows but once I switch to hot side the fan does not blow any air at all. The hot or cold control on bottom left does not affect anything. I don't have a/c. I just want to get it to blow iether hot or cold air when put on hot(on top selector) Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 26, 2010 Share Posted January 26, 2010 I'm talking about the top selector on the temp control. When it's on the cold side the fan blows but once I switch to hot side the fan does not blow any air at all. So when you switch it to the hot side, the fan turns off? Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted January 26, 2010 Author Share Posted January 26, 2010 So when you switch it to the hot side, the fan turns off? On the top selector yes. The one with like 5 different selection. The one with two(hot or cold) it doesn't affect the fan. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 26, 2010 Share Posted January 26, 2010 Hmmm... I never noticed it doing that on mine. Not to say it dosen't. It must have a purpose. I still think you should be able to slide the top selector to heat, and slide your hot/cold selector all the way to hot (to the right) and turn your fan switch on, and get hot air coming out of the unit. If you slide the top selector all the way to the right, that's for defrost, correct? Something tells me the problem still may lay in the vacuum lines. that's the most common trouble causing issue with these hivac systems. Sorry I couldn't help you any further... BTW, I'm going off memory on the selector positions, since my car is out of reach right now... Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted January 26, 2010 Author Share Posted January 26, 2010 Hmmm... I never noticed it doing that on mine. Not to say it dosen't. It must have a purpose. I still think you should be able to slide the top selector to the first click to heat, and slide your hot/cold selector all the way to hot (to the right) and turn your fan switch on, and get hot air coming out of the unit. If you slide the top selector all the way to the right, that's for defrost, correct? Something tells me the problem still may lay in the vacuum lines. that's the most common trouble causing issue with these hivac systems. Sorry I couldn't help you any further... Yes so basically from the right (defroster) side the first two click turns of the fan. After that the mix of hot n cold is half power. Does our heater require a vacuum from the engine bay? Because I have no vacuum that leads inside. Also the vacuum lines are located behind the climate control? Thanks Quote Link to comment Share on other sites More sharing options...
Jon 74 260Z Posted January 26, 2010 Share Posted January 26, 2010 Does our heater require a vacuum from the engine bay? Because I have no vacuum that leads inside. Yes. Although, IIRC, you can get heated air to the defrosters with no vacuum lines... Connect the appropriate vacuum lines and report back. It's easier to get to the connections by removing the center console then it is from removing the ac/heater control console -- the connections are about 2" above the transmission tunnel "hump" behind the back of the radio. Note: The FSM actually does a good job describing where you should have hot, cold or fresh air depending on the positions of the control panel switches. Best of luck... Quote Link to comment Share on other sites More sharing options...
p-factor Posted January 26, 2010 Share Posted January 26, 2010 Just to clear all the bases, when you slide the lever to "HEAT" you know that it only comes out of the floor registers, right? It wouldn't make any sense at all for the fan to actually stop running, you just might not be able to feel the air moving. I didn't think there's anything related to vacuum lines on a '74, I thought it was purely mechanical movement of the ventilation baffles? Or am I mistaken... Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 26, 2010 Share Posted January 26, 2010 (edited) Yes so basically from the right (defroster) side the first two click turns of the fan. After that the mix of hot n cold is half power. Does our heater require a vacuum from the engine bay? Because I have no vacuum that leads inside. Also the vacuum lines are located behind the climate control? Thanks Edit: Removed incorrect info. Edited January 26, 2010 by J. Soileau RB26zcar Incorrect info given by myself.... Quote Link to comment Share on other sites More sharing options...
7MGFORCE Posted January 26, 2010 Author Share Posted January 26, 2010 I will check this out tomorow when I get a chance to work on in and report back. Thanks Quote Link to comment Share on other sites More sharing options...
zcarnut Posted January 26, 2010 Share Posted January 26, 2010 ...I don't have a/c. … Guys, don’t confuse 7MGFORCE. The non-AC 260Z’s do not have (or need) the vacuum operated heater duct doors. It uses cables for everything. Quote Link to comment Share on other sites More sharing options...
p-factor Posted January 26, 2010 Share Posted January 26, 2010 Guys, don’t confuse 7MGFORCE. The non-AC 260Z’s do not have (or need) the vacuum operated heater duct doors. It uses cables for everything. ...I thought so!... but I'm new to the Z so I didn't argue. I'm quite sure when I move my levers it is just mechanically opening and closing the baffles. My my initial question for the OP remains, are you sure the fan stops turning completely and not just coming out at the floor? Quote Link to comment Share on other sites More sharing options...
Guest ttoude Posted January 27, 2010 Share Posted January 27, 2010 look for a vacuum problem Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 27, 2010 Share Posted January 27, 2010 look for a vacuum problem Do you read anything before you post?? Quote Link to comment Share on other sites More sharing options...
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