1991 Aerostar with no heat.

[ken freeman]

I have a 91 aerostar with 3.0 motor. it runs great,but i can't get any heat out of the heater. the temp gage also reads low. i recently replaced the heatercore and hoses and tried two new 192 degree thermoststs. the water level is fine. the fan clutch seems ok. i have cheked the function of all the vacuum servos on theheater box and everything seems to open and close correctly. also adjusted the temp control cable. Any one have any ideas?

 

[BrooklynBay]

Welcome to this forum! Did you check both heater core hoses to see if coolant is flowing? You might have a clogged heater core or a bad water pump. I understand that everything was replaced, but we have to start troubleshooting.

 

[ken freeman]

yep,checked the hoses. the core was just replaced. the truck always runs cool even in our 100 defgree summer so i assume the water pump is working ok.

 

[BrooklynBay]

Do you have an IR temperature gun to check the actual temperature of the engine, heater core, and hoses?

 

[ken freeman]

heater in aerostar.

i checked temps with a digital heat gun. it looked like poor circulation. i removed all the hoses and flushed the heater core and engine/radiator out. very nasty. now i am getting 109 degrees from the vents.

 

[cecil guy]

hello ken freeman, my name is cecil freeman. I have a problem with my 1993 aerostar. Headlights blinking on and off after running for 30 mins. or so. All fuses are good and have determined most likely relay switch is the problem. My quesion is the relay switch located along with the fuses in the fuse box or is it that 2inch by 6inch box mounted on the drivers side fender engine compartment.

 

[BrooklynBay]

Welcome to this forum! Do you have automatic headlights with a light sensor such as what is used in Canada? Since this thread is about heating issues, I would suggest starting a new thread in this section.

 

[snakebitten81]

I have a 97 areostar 3.0l engine I replaced rad last fall it was leaking all new hoses. Can't get very much heat out of heater. I changed heater core installed 195 themostat checked and adjusted hot cold door checked vacuum shut off valve for coolant going to the heater core under the hood still have only warm air. Even after changing thermostat engine runs at 1/4 on temp gauge no higher even with rad partly covered with card board to try. My lower hose has a molded hose on it going up to the intake manifold right where the temp gauge screws in. It has a tee and the temp gauge is on top and the hose attaches under. I noticed that earlier models don't have this on their lower hoses. My tee that screws into the intake rusted through last summer couldn't get a new one from ford so I made one with plumping pipes same thread and all. Is it possible that the orignal part which I chucked out had a smaller orfice and didn't let as much coolant flow. I would think this set up would let the engine run cooler because there is always a certain amount of coolant from the cooler rad circulating through the block by passing the thermostat. Has anyone else had this problem will restricting the flow of this hose help or can I block it off all together.

 

[BrooklynBay]

Check the temperature of both heater core hoses.

 

[ken freeman]

I had the same problem. after flushing out the entire cooling system there is fair heat,but not great. My temp gauge still reads low. I also wonder if the bypass has something to do with this?

 

[speleopower]

Have you opened up the heater core/A/C enclosure? Mine was almost blocked by leaves and other debris from over the years.

 

[snakebitten81]

I have opened the a/c heater box just a little pine needles cleaned it all out ,that would only restrict more the flow of air than the temp of it. I know the core is not blocked it is new along with rad and hoses. I haven't checked the temp of the heater hoses with a laser checker yet. But the other day I noticed that the temp right where the hoses leave the intake are a lot warmer than right where they go into the heater core. There is no reason for a temp drop in that short of distance. It has me baffled I'm a automobile tech by trade for thirty years and I have never run into something like this.

 

[BrooklynBay]

Check the flow going through the heater hoses. Maybe there is a problem with the water pump?

 

[speleopower]

Check the little vacum servo. Move it by hand and see if hot water starts going to the heater core.
Could it be the NEW heater core is blocked?

I need to replace my heater core and can't get the hoses loose without taking the A/C dryer off.

-Scott

 

[snakebitten81]

I checked the vacuum valve it is open all the time except when the A/C is on When I pul on the servo in cuts the fow to the heater.My van is a 97 and the hoses have a quick connect on the heater core and are a but impossiblle to remove in such a litte space if yours is the same speleopower you can remove it with out touching your A/C. Remove heater box cover behind glove box that covers heater core.Take a little pneunmatic air saw uses sma bade like hack saw but shorter. Pu heater core awy from the box enough to get blade in and cut ends on heater core.

 

[BrooklynBay]

You don't have to cut the heater core in order to remove it. There is a special tool for releasing the push in connector.

 

[speleopower]

What is the special tool? I figured there is a tool for it.

 

[snakebitten81]

I released the hoses but the plastic clip remains on the tube of the heater core and won't pass through the hole in the fire wall. The space is so confined there is not enough room to lift the tabs to slide the plastic clips off. Depending on the age of the van when you try to unlock the clip it seperates and half of the clip with the o-ring stays on the heater core tube. It's the same design as the fuel lines on some ford and GM's but larger diameter.

 

[speleopower]

I'm just going to cut the tubes from underneath the dash and call it good. Right now I have the heater hoses off of the heater vacuum selector valve and looped together with a piece of copper tube clamped in the heater lines so I can still drive my van.

Now that I have been thinking about my heateras well I think I had a similar issue with no heat last winter. It was intermittent. I would get heat to blow sometimes and sometimes no heat would come out when the heater was selected.

I don't remember what resolved the issue. I do remember I had a couple of vacuum lines that had tiny cracks but only on occasion would they bend open causing my A/C to not select properly. I did replace the radiator, thermostat, heater vacuum select valve and my A/C system this past summer.

-Scott

 

[BrooklynBay]

What is the special tool? I figured there is a tool for it.