4th Gen Heater QUICK FIX and PERMANENT FIX

Addendum - STEP 2:
Here's how it looks unclipped. It'll shift every once in a while, so check it.
*Don't lose that little clip. If it falls out, put it in a safe place.

 

Re: 4th Gen HEATER QUICK FIX

PERMANENT / SOLDERING FIX

Cross referenced to this write-up (a must read!):
viewtopic.php?f=48&t=878




Don't forget to check the 'piggyback' board:


Addendum:
I HAVE IDENTIFIED THE HEAT SERVO PINS!!!

Edit: the info below refers to the Canada and USA LHD 88-89 HVAC panel only - the 86-87 ones are different and I have not diassembled that one yet.
This last pic is something that's been plaguing us 4th Gen'ers for a long time.
I believe I've finally identified which leads go to the heat slider bar - they are the No. 1 and No. 10 Pins. If you resolder all the red circled points, it should fix your heat.

*Note: these are the most common ones that crack, but if you've come this far, check over everything*

If you try it and it works for you, post feedback

 

Re: 4th Gen HEATER QUICK FIX & ALTERNATE AC FIX

You need a soldering iron with a fine tip
Just heat up each solder point to re-melt them as some have cracks in them

 

Also, don't be alarmed if yours looks different - There are L/hand and R/hand versions.
Each year (apart from 88-89) got different versions of these
JDM's are totally different with extra functions and different boards

Very difficult to say what goes where as there's 9? different types out there

 

step 1 and 2 checked out ok. The lever and wire for the heat er works fine. So thats not the problem. Maybe the thermostat could be shot?

I have an 87 3s-ge, European left hand drive.

 

If the levers are moving that's a good sign

When last did you flush the radiator & motor? Have you flushed the heater radiator?

 

I have just flushed the radiator two times, and out came a lovely rust-red liquid it's better now though. But I haven't checked the heater radiator, where is it located? better check my haynes manual

 

When you do Step 1 & 2, do you get heat coming into the cabin?
If yes, then the problem is usually cracked solder connections in your HVAC panel.

The 87 HVAC panel looks different that the one pictured, but if you look for cracks and resolder them, that should fix your problem.

Here's more info on the Permanent Resolder Fix:
viewtopic.php?f=48&t=878

 

the wire and levers move as they are supposed to, but still no heat

 

Just to clarify:
You left them in the open positions shown above,
with the car fully warmed up and blower fan turned ON,
and still no heat?

 

I did, but Im gonna check it again with the engine good and warm

 

If you do what is described above, you should get heat.
If not, possible causes could be thermostat stuck closed, a blocked radiator and/or coolant/heater hoses.
Let us know, I'm curious

 

btw.. where is the heater radiator located?

 

Mines in a big white box under the dash, there's two pipes facing the motor.
You will need to disconnect them and force water through them each a few times.


As you can see the design is bad in that there's no way for muck to exit and it acts as a mud trap

This one was so bad I removed it and had it chemically cleaned

Yeah all 4 of my cars had blocked heater rads, rads and motors - you gotta disconnect ALL the hoses and blow everything out
Use anti-freeze, it's the best way to prevent this from happening

 

Is it a pain to get out of the dash? Might be easier to change the thermostat first...

 

You'll have to pull the dash someday to fix the leaking flaps

for now just follow the pipes to where they enter the firewall, pull them off and flush
the radiator in the dash, you should be flushing the entire motor and radiator as well

 

Nice! I'll find the hoe's (pardon the pun), pull them out, shove the waterhose in there and flush it. Should I be afraid of leaks inside the car?

 

The pipes are on the firewall behind your motor!
Just follow them from the heater valve, I'd put pics but my RHD is different and I'd hate
to confuse you more after showing what's inside the dash and why the problem occurs.

 

i took the car out for a spin now. Drove about 15 kilometres. When i stopped the radiator upper and lower hose was warm and white smoke came from the radiator. Might have been cause of external water from a puddle though.. I guess ill change the thermostat and waterpump and see what happens