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Doug's heater

Hey guys,
I had this problem a couple of weeks ago. I didnt have time to read all of the post to find out where you are at, but I thought I would let you know how I fixed mine.

I removed the 3way valve just off where the hoses come out of the heater core. I blew out the valve and got some crap out of it (plastic?) I also "lightly" blew some air through the heater core.

I now have heat!!

Mike Bauer
Error codes

As Doug has discovered by the Auto lite not flashing he is not likely to have error codes stored in the system. But, aren't the error codes for the Electronic Automatic A/C displayed on the control head (not the ALDL). If you need the access to these codes, just ask, and I (or somebody) will walk you through it. FYI: The Factory Service Manual, Chiltons, and any other manuals are worth their weight in gold (just about as much as they charge) if only to get a correct diagnosis before heading to your local mechanic.

Be glad you didn't have error codes, otherwise your C-4 interior would soon look like the picture that I will attach to my next post under "How can I test this thing?

I think....

That the ccm will store these codes as well, thus the A to G jump instead of the old A to B
for the ECM errors.

However somewhere down the road I posted the how to probe the AC head as well.

Good point though...Ohmydog did I give poor Doug the wrong info!!!




To get at AC trouble codes in the head

Diagnostic Trouble codes

So the MODE button you have depresses will flash for one minute the go out...

Hold the arrow up & the arrow down buttons for 5 seconds the display will show 00
( to let you know your in )
Hit the Auto button
and is should scroll through the code(s) that you have

00= No problem
01= temp door motor goof
02= temp door motor goof ( different problem )
03= ambient sensor OPENED UP/disconnected
04= ambient sensor Shorted out/ kaboom
05= internal sensor OPENED UP/disconnected
06= internal sensor Shorted out/ kaboom
07= Solar sensor ( in dash ) open
09= Low gas
10= CPU has blow it's mind

After this is done...by pressing the up & down arrows you can pole the different circuts and when you find the one you are looking for
Press AUTO
and it will tell you what it thinks it sees.

To get out of Diag's

Hit defrost..( or any other AC control)

Ta Da
Hi to all,

I know that I said that I would get back on my heater on Monday (01/21). However, I was unable to do so until today (01/24). I finished up at about 11:00 pm E.S.T.

I isolated the heater core and back flushed and forward flushed it until I had a flow of clear water. This took a total of 8 flushings and about 16 gallons of water. I found that if I would stop the flow of water once it became clear and blew out the circuit (lung power only) I would get more dirty water. I continued doing this until I had only clear water.

I put the heater core back in the cooling system and added coolant to the bottom of the filler neck. Then I bled the cooling system, started the engine and added more coolant when needed. Put the radiator cap back on and let it warm and .............. TA DA, I'v got HEAT!!! :J :J

Thanks to all of you who helped me through this, especially VIGMAN!

Happy and safe motoring to all!


So in 2 weeks have the cooling system flushed
totally..If you had that much gunk in the heater core..it stands to reason that a similar amount of junk resides elsewhere.

Plus you will be freeing more gunk in the heater core.

Do the jiffy lube thing

Treat yourself

Let somebody else do it...

I was thinking of that, but I was also thinking about doing it myself.

If anyone has any tips on flushing the cooling system that I should know about, whether I do it myself or have someone else do it, I would greatly appreciate it.


You might seriously consider a major flushing...the only time I have heard of a heater core stoppage on a car as late model as yours was a friend who mixed incompatable antifreeze solutions. It makes an incredible jelly-mass. Just my $0.02 worth.


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