Best Answer

Heater could just be air bound and need to be bled It may have a bad heater control valve. If it has one, it will be located on one of the heater hoses by the firewall. Check the valve, and check the vacuum line going to the valve, as it may have rotted, and have come apart where it comes from the firewall, and to the valve. And also, the valve could be frozen in the closed position. If the Heater Control Valve is working-FEEL BOTH hoses-IF one is not HOT then U have a Blockage-Like a blocked heater Core.IF U put a Garden hose on one of the inlets U should have flow (both ways) check 4 a pinched or collapsed hose. If all The Previous items are checked it is possible , If the car is equipped with climate control that this portion of the system is At Fault, this was also a common problem with these cars as they aged.

User Avatar

Wiki User

โˆ™ 2007-03-25 19:04:29
This answer is:
User Avatar
Study guides

Add your answer:

Earn +20 pts
Q: Why doesn't a 1989 Mercury Grand Marquis heater get hot even after the thermostat was replaced?
Write your answer...
Still have questions?
magnify glass
Related questions

1991 mercury sable gs 3.8 liter v6 you just replaced the water pump and now your heater doesnt work and the thermostat is fluctuating and your coolant resovoir is full to the top?

check for air in the system vapor lock stinks but its not hard to fix

2001 grand marquis windshield assembly?

I have mercury marquis 2000 windshield wiper it works only on HI when i turn it low it doesnt work or lower than low stile doensnt work would you plz help me?

How to replace crankshaft position sensor on a 1983 mercury grand marquis 302 v8 engine?

1983 doesnt have a crankshaft position sensor. you have an ignition module located on the side of the distributor.

Can a temp gage go bad on a Mazda b3000i replaced the temp send unit and the temp gauge still doesnt register the fuses look goodim stumped?

change your thermostat....

S-10 stalls when its warmed up then starts after totally cooled down?

it is most likely going to be your thermostat needs to be replaced. and if that doesnt work than time for a new radiator.

Why doesnt the overdrive work on your 95 grand marquis It was working fine at first then stopped working I replaced the OD syliniod and trans filter?

Check the fuse. If it has a manual OD switch to turn off and on be sure it is on.

Why would your 96 accord be overheating when its full of fluid and you replaced the thermostat and the temperature gauge doesnt go past a quarter and you smell antifreeze under the hood?

It could be that your heater core is blocked or damaged somehow.

Why doesnt a 2000 Chevy lumina operate at normal temperature?

Replace the thermostat.

Why doesnt heat work in 96 Dodge Intrepid?

could be a sticking thermostat.

What can cause your 2001 Chevy Malibu to overheat?

if the pump and thermostat have been replaced on a 2001 malibu and it overheats and the heat doesnt work now but the air does. do it need bleeding still , will air in the line still cause that problem...

Why doesnt Mercury suport life?

Mercury does not have enough atmosphere and is too hot / cold to support life.

Cooling fan doesnt come on till 260 degrees?

may be a bad thermostat

People also asked