Heater Problem

[Mr. Land Yacht]

I have this small problem with my heater.
once it warms up it blows nice and hot for a while just like it normally should and all...but after a little while it stops blowing warm and starts blowing cold.

I'm guessing a bad thermostat...yes/no?
what degree thermostat should I be running?
the guy that sold me my Vic Jr intake last year said the thermostat in it was fairly new, but maybe it wasn't....and it could have been one of those cheapo crap ones.

thanx for any input.

-Colin

[gadget73]

ATC or non-ATC? ATC has its own set of possible issues that non-ATC won't have.

Do you have a temperature guage in the car? What temp does it run at?

Thermostat should probably be a 180 or 195. Engine temp should be somewhere in the 190-210 range normally. Thermostat that isn't regulating could make it run too cold, you'd see this on a temperature guage.

[91waggin]

OEM temp is 195, iirc

[Mr. Land Yacht]

I got ATC.

my gauge normally stays about 195ish...200 on a really hot day.

When it starts blowing cold with the knob on Auto, then I put it to Medium(since High doesn't work) and it still blows cold.

incidentally, is there any way to fix that speed knob to make High work again?(not as important right now)

[gadget73]

the auto position only works the fan. I'm going to hazard a guess and say the interior temperature sensor is bad. Open your glovebox or look up behind it from underneath and find the clear vacuum hose connected to the gold can directly behind the glove box. THis is the one that the nipple faces the back of the car. Pull that hose off and see if you have heat. If you do, the temperature sensor in the dash died on you. Unplugging the vacuum line will give you full blast obnoxious heat all the time. If that happens, replace the sensor. Its under the dash pad above the glovebox. Sensors were about 30 bucks last I knew.

[86GmLsCoupe]

For the fan speed, try checking the connection at the blower resistor. Mine lost high a few weeks back and wiggling the plug got it back. The plug is on the passenger side in the engine bay connected to the airbox.

[Mr. Land Yacht]

thanx gadget.
Do I have to take the whole glove box out or can I just take off the bottom padding and reach in there?

Also, if I unplug this vac. hose I will have full blast heat all the time and moving the temp knob down would do nothing?
Or would it just blow full heat all the time if I keep the fan setting on Auto?

[1987cp]

I have a manual temp control panel you can install for very close to free. (assuming it's a feasible swap, that is)

[Mr. Land Yacht]

I think I'll just pull that Vac. line for now.
will that cause any damage?

[gadget73]

You can remove the panel on the bottom, or flip the glovebox open fully. I think it requires a screw to be removed to go past the stop. Unhooking the vac line won't hurt anything as long as you plug it. The worst part about it, you'll have no way to regulate the temperature and it will probably get uncomfortably hot. If your windows work, you can sort of regulate it by how far you have them cracked.

[Mr. Land Yacht]

so if I was to remove this Vac line and the heater is running...I can't cool it down by moving the temp knob down the blue area? it will have no effect?

[Lincolnmania]

no you are defaulting to full hot
if you want it right get a brandy new atc sensor from ford

[Mr. Land Yacht]

I have no problem with full hot..I can always put the fan speed to Lo...or open a window...I liek heat. lol

[Lincolnmania]

you people are fucking idiots.........atc sensors are no good after 20 yrs

[Mr. Land Yacht]

I removed and plugged that Vac. line...blows nice and hot now.
Thanx.
I might replace the sensor later.