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Discussion Starter · #1 ·
Tried to warm my car up this morning and my heat wouldn't work. What steps do I need to take to find my problem?
 

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What do you mean by not working? Do you mean the fan doesn't come on, or only at the slow speed? Do you mean the fan works fine but not heat comes out?

If the fan doesn't come on it may be a bad fuse, bad fan, or a bad resistor pack.

If the fan works fine but just get cold air, then most likely the heater core is clogged. You can try backflushing it but given the age of it may just want to go and replace it, and when doing it also would want to do a flush and fill of the whole radiator fluid system to get all the old coolant and debris out of the system. Also while you are in there may want to replace the flow restrictor and the T fitting that goes between the heater hoses and the coolant tank as both parts are plastic and known weak points in our cars. - Peter
 

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Discussion Starter · #3 ·
the fan blows fine, but I noticed today that when I turned the cold/ hot knob so it wouldn't be so cold, it didn't make a difference. It kept blowing super cold. Is this still the heater core?
 

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"It kept blowing super cold. Is this still the heater core?"

Yes.
 

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Discussion Starter · #5 ·
So i'll just replace it then, should I flush it b4 or after the new heater core?
 

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It kept blowing super cold. Is this still the heater core?
Is your thermostat working - engine temperature up to normal?
If so your heater core could be plugged. Search in this section, there are many posts about cooling systems full of crap that will plug a new heater core in no time. You may need an extensive cooling system flush.
 

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A heater core is basically a small version of a radiator. There are a tube that zigzags with fins over it. The hot coolant flows through the tube heating it and the fins. Then, you have a fan that blows across the tube and fins giving you hot air. Now if there is an obstruction in the tube, the coolant will not be able to flow through it so the fan will be blowing on a cold tube thus giving you cold air.

So your heater core that is in your vehicle is clogged. You can try to back flush it, but be careful because it is very delicate. Mabe try a garden hose only half open.

So i hope that answers your question and learns ya sumpthin :D

P.S. flushing a new heater core will do nothing as you probably know now;)
 

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also check the vacuum line make sure when you turn it to heat the valve actually opens the heater core

here are some pic from my car

they are under dash behind radio and ashtray assembly
 

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After it's been running for a while check the heater hoses, if one is hot and the other is luke warm you probably have a clogged heater core, if both are hot then the door control in the heaterbox under the dash is stuck.
 

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Discussion Starter · #12 ·
Great information, guess I'll be busy this wknd!
 

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I just fought this same issue so I'll describe my fight and try to steer you in the right direction.

1. Let your car get up to normal temp and feel the two heater hoses. They should both be warm/hot to the touch. IF one is noticeably different your heater core is clogged. To fix this you can unbolt the heater hoses from the fire wall (After you let the car cool) and stick some flexible plastic hoses on to them. Stick one hose in a bucket (or whatever you want to catch the crap in) and try blowing in the other and see if you can get anything to come out the other end. I had some movement in mine. Then stick one of the ends to a faucet and turn on (GO SLOW IF IT'S REALLY CLOGGED) You should start seeing a bunch of crap flowing into your bucket. Pulsating the water flow can break some stuff loose too. Switch the hoses at the firewall and repeat in the opposite direction. Hook back up and see if you get heat. You will need to add a bit of coolant/bleed system for air.

2. If both hoses are hot and your getting no heat. Turn on the car and turn the knob from cold to hot. You should hear a noise of the door closing which is located kindof in the passenger side floor space. You can see this thing in action if you remove the lower part of the dash.

Much thanks to "TheFooserGuy" for his help getting me heat!
 
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