AMC Eagle Den Forum

The Shop => Under the Hood & HVAC => Topic started by: Dubv on October 19, 2015, 12:14:36 PM

Title: Weird Heater issue
Post by: Dubv on October 19, 2015, 12:14:36 PM
So I had a new set of HVAC controls installed this past week along with a new A/C thermostat in my '84 Eagle Limited.  I now seem to have an odd problem with my heat which may just be coincidence with the other work, or related.
The heat seems weak, and especially if I move the lever all the way over to the "hot" side of the slider.  If I leave it somewhere in the middle, it gets warm, but it takes awhile, and its certainly not as hot as it used to be.  I checked the heater control valve and the vacuum switch is moving all the way up and down.  The heater core has been replaced fairly recently (last few years) so I don't think it should be clogged.  The temp gauge shows the car is reaching normal temp.
Any thoughts?  Could it be something internal in the heater control valve?

Thanks for any ideas!

Chris
Title: Re: Weird Heater issue
Post by: vangremlin on October 19, 2015, 01:33:51 PM
It might be that some of the cables didn't get put back in the proper place, or didn't get cinched down to the control.  There are 6 or 8 cables plus a vacuum hose or two on the controls.
Title: Re: Weird Heater issue
Post by: Dubv on October 19, 2015, 05:05:56 PM
I had a fellow who was a factory AMC tech install the thing for me...so I HOPE he did it right as far as the cable hook ups goes.  That's why I had him do it and not me..hehe.  Any other thoughts?
Title: Re: Weird Heater issue
Post by: AMC of Houston on October 19, 2015, 06:26:29 PM
Maybe the engine is just not getting hot enough; like maybe a bad thermostat??
Title: Re: Weird Heater issue
Post by: Dubv on October 20, 2015, 05:04:54 PM
The temp gauge shows it getting up to normal operating temperature.  The only thing I can think of is that the heater control valve is messed up unrelated to the vacuum switch working correctly...OR...there is something wrong with the cables. 

Title: Re: Weird Heater issue
Post by: Amc1320 on October 20, 2015, 05:22:19 PM
Sure sounds like something wrong with the cables, when you move from cold to hot can you hear a "clunk" noise of the flap moving over near the passenger floorboard?
Title: Re: Weird Heater issue
Post by: JayRamb on October 20, 2015, 06:45:18 PM
have you checked the vacuum heater control valve near the heater motor?
Title: Re: Weird Heater issue
Post by: Dubv on October 22, 2015, 12:06:23 PM
Yeah, the vacuum control is working fine, it moves the switch on the valve fully in each direction.  Does anyone have a diagram of how the cables should be connected from the workshop manual?
Title: Re: Weird Heater issue
Post by: AMCLOVER258 on October 24, 2015, 01:22:09 PM
It could be air in the core, try letting it warm up then slowly allow pressure to release from the hose, when i first got my eagle i had the same issue until i burped the core.
Title: Re: Weird Heater issue
Post by: vangremlin on October 24, 2015, 02:21:28 PM
Here is a picture of the controls from the 1980 TSM.  Let me know if you'd like me to email you a copy.  Thanks.

(http://i62.photobucket.com/albums/h109/brilliantd/e4acc18e-4bb2-495a-afce-ae4ef4c9d291_zpsqwyytl2p.jpg) (http://s62.photobucket.com/user/brilliantd/media/e4acc18e-4bb2-495a-afce-ae4ef4c9d291_zpsqwyytl2p.jpg.html)
Title: Re: Weird Heater issue
Post by: Dubv on October 27, 2015, 02:15:19 PM
Thanks!  Exactly what I was looking for.
Title: Re: Weird Heater issue
Post by: carnuck on November 01, 2015, 12:45:52 PM
Try unhooking the vacuum to the heater control and plugging the hose to see if it gets warmer. If not, then above the box on passenger's side is a cable (that I have to replace the clip on) which may be out of adjustment.
Title: Re: Weird Heater issue
Post by: olymunch on November 27, 2015, 12:32:51 AM
Where did you get your new hvac controls?
Title: Re: Weird Heater issue
Post by: carnuck on November 28, 2015, 11:14:37 PM
I have some from a pre-Chrysler XJ and FSJ that I saved for mine.