Hello everyone, I currently own a 1999 Acura TL I have been slowly but surely fixing up and I have found this site extremely helpful with the majority of my issues I have had with this car since I bought it. I tried to fix this problem without making a post about it but I can't find any descriptions of anyone with a problem just like mine. So I apologize on advance if this is already out there Shortly after summer ended I realized my heater wasn't working and that only the air conditioning was working, and everytime I tried to put the heater on I would hear a clicking for about 30 seconds as well. I came on this site and did some reading and found a few threads talking about the valve behind the engine that needs to be sprayed with a little wd-40 and cleaned up so it sounded easy enough I went to the garage did it and wolah the heater began working again. However I did notice the clicking stopped happening when I put heat on and started happening when I put the ac on but it still worked. It worked for about two weeks and in that time I noticed there was no in between on my system even if I had it set to 70 degrees inside it was either hot or cold... But it worked and that was what mattered until a couple days ago I while driving I tried to put the heat on and nothing happened, then I tried ac and nothing happened again, I messed with it a little bit I would hit the button and it would light up and say it was on but nothing would happen. I got on here and found a little more information on diagnosing the problem I checked all my fuses and all came out good, I checked the relay and it came out good, the wiring harness looks to be in good condition still, the heat sink is still in good condition, I tested the transistor and it appears to be good as well. Tonight after work I will be hooking up the blower motor to a battery and testing it next... But for some reason I have a strong suspicion it will test fine also. But well see my question is surely I made a mistake here and I'm not the only one who has encountered this problem. Anyone have any information on something similar to this and what it was for you? Could be for me?

 

Welcome OlyUA5 !!!
~ Try running the climate control's self diagnostic feature.
~ The blower motor wiring harness and transistor pack are common problems.
~ Perhaps the air mix control motor is malfunctioning, check for the "DIY" fix for this.
~ The info is all here if ya can learn how to use the "Search" button, It's here and been done !!!

 

Hey quick question how do I run the climate control self diagnostic feature?

 

-----> To run the climate control's self diagnostics :
__________________________________________________ _________________________

~ Turn ignition key to accessory position
~ Push "AUTO" button, then also "OFF" button, and hold them both in
~ If there's an error code, the LED temp indicator will display a digital letter
~ An "88" will alternate with a code "A" thru "N", no code if nothing is found wrong
~To end diagnostics, simply turn the key off

~Post code for more assistance, for example:
"N" = blower motor short, "I"-"J"-"K" = air mix control motor, "L"-"M" = mode control motor

 

I just got it all put back together, I'm about to run the diagnosis will update once I know more thank you

 

Ok so I just tried the climate control self diagnostic and I got the 88 to come up multiple times but all it would do after the 88 came up was a little line on the screen no letter ever appeared I'm a little confused now I take it that means it couldn't find anything wrong?

 

back to manual figuring things out!

ck the mix motor as most likely candidate- and smooth operation of the main heater valve you keep wd'ing
Everything is in our diy section- you found that at the bottom of main gen2 TL page?

the cabin air filters were good condition (did 99 have those?)

 

lol guess so. Yes I found a post about the main heater valve on the DIY and a post with the 4 most probable reasons... I'll search through the DIY some more tonight. And also as far as the cabin air filter I'm not 100% sure I could be wrong but I believe while I was under the glove box I seen a air filter is that where it would be?

 

Hey OlyUA4, if you've lubed the heater valve and cable to make sure that it was working freely, and have verified that the blower motor and transistor pack are good......

then check out this air mix motor repair "DIY" from Skirmich :

https://acurazine.com/forums/second-...repair-848488/

 

Ok thank you, I'll have some time to do more work on it tomorrow, earlier today I drove it and the heater and air conditioning worked until I got to my destination turned it off, the next time I started it up it didn't work again. Feels like their is a light breeze coming out of the vents.

 

when you were working on the blower itself- you passed right by the cabin air filters!
behind a small plastic panel- a slide out plastic tray holds the 2 filters side by side

if they have been replaced before, that panel sits sideways and does not cover the filters completely- its ok- they made it that way
if NEVER changed in 15 years (yikes!!) that piece will be attached by 2 tabs on 1 side- they bend and break off as designed

note: Acura calls for replacement every 12 months or sooner if high construction dust or other badness in your air

 

is the engine temp dead steady at 1 or 2 lines below halfway?

 

how old is the engine coolant? more than 5 years?

 

Yeah the engine temp sits just a couple slivers before halfway, coolant is maybe 2 months old I flushed It and filled it all the way up. I'll have to check the air filters tonight. Been working the last few days still haven't figured it out sometimes it comes on and works but it's not rare. Not sure if the cabin air filter has ever been replaced.

 

wait a minute! you changed coolant--did the problem start after that?

when you refilled it-- did you open the heater by turning it to full HOT with cabin fan running AND following owner book instructions on burping???
with the ~15 minute procedure involving 2000 rpm holds till fan cycles on and off plus idle and fan cycles etc

any hidden trapped air will really mess with you!

also ck the rad cap, the res bottle cap is on tight? and the hose inside res cap that sits in the reserve coolant is attached firmly- or the transfer/recovery system wont work
use zip tie!

 

Well since the day I bought the car the heat hasn't worked only the ac would, but other than that everything else has worked fine. I had a little overheating problem during the summer it ran close to dry. So I bought a new radiator cap and followed the directions of a post on this site I believe I did it all correct I did rev it until the fans came on and everything like it said, however at the time I didn't have heat working so I'm not sure if that messed something up. I have been constantly checking my fluid levels. I can check it all out again right quick. Maybe even redo it. The last few days I've contrinued driving and it almost seems like it's still working or trying to at least just not blowing as hard as it should be

 

Perhaps try installing a new OEM 2 stage Thermostat.

 

make sure the heater is open at the valve on firewall and do a re-burp of the radiator
Follow book exactly- free copy download here Acura Owners Site | Exclusive Knowledge, Service, & Benefits
Have to have that as a known good point to start the search! no air anywhere
Its more than just 1 time of fans operating to burp system

if the temp is steady I doubt the thermostat is at fault, but never hurts at 100kmiles to replace it
You are not having an engine fan run for 5-10 minutes after shutdown of engine are you? that would be fan sensor A at radiator bottom corner

 

on the other hand you ran it nearly DRY!!! What was the cause of that?
May have popped a head gasket
any loss of coolant now- or increase in oil level ?

any coolant smell in car after the heater is ON full hot briefly? ck passenger floor area for wetness
If the heater core was leaking, the last owner may have shut off heat - that would cause strange problems if it allows air leak

 

Ok I'll make sure to reburp the radiator I'll buy a thermometer from work and install it as well tomorrow also. you know now that I think about it I haven't noticed it in a while but during the summer on the hotter days I did notice the fan would keep running after I shut off the car. Not so sure what the cause was of it running dry I was assuming it had to be a leak that also was during last summer however since then I have replaced the rad cap topped it off with antifreeze and checked it religiously and it seems steady now, no leaking on the passenger side from what I can see, however I think I've smelled antifreeze while the ac/heat is on full blast. Thanks again for all your help.

 

are you saying you work at the dealer--buy part at work?

Get genuine direct from Honda- 2 stage thermostat
NOTE on installation- a dot or mark has to go a certain direction, see our helpful diagrams in threads or diy list

if driver fan was running last summer- after shutdown- the engine was hot AND possible sensor problem in the making
I would get a new fan temp sensor A now, it goes on the thermostat housing on a 99 so you are right there anyway!
Its failure will really mess with the engine and cooling, battery and more

 

you can borrow pressure tester for the cooling system at parts stores
Find any leaks and fix immediately
ck water pump underneath for trail of off color crud from its weep hole

 

no I dont I wasn't thinking straight when you said oem for some reason I'll make sure I go through the dealer for both parts. Pressure tester is something I should be able to do at my work however.

 

Yeah, start with pressure checking the cooling system for any potential leaks.

For a '99.....if previous pm is unknown and considering the recent overheat situation, do as 01tl4tl previously suggested......replace the ECT thermosensor for cooling fan and replace the T-stat with a new OEM 2 stage. When installing T-stat, position the pin and sealing gasket with the pin oriented at the top of the housing.

Afterwards, be sure to properly "burp" any air pockets from the cooling system.

 

finally- somebody with helpful information on that install trick- its VERY important. nee CRITICAL to its operation

in burping radiator/cooling system: the Heater must be on full HOT/highest temp setting
and cabin fan run on HIGH ,,,,OPEN the doors and windows (plural) so heat can escape and you don't get heatstroke in the winter
Its all right there in the owner book

 

Look for a loose hose clamp or a pinhole leak under pressure ?

 

water pump weep hole on its bottom side is another good place to look

 

Alright thanks guys I'll pressure test tomorrow and go from there. I'll keep you posted on what I find I appreciate all the knowledge.

 

Alright so if anyone is still interested here I took a little break from fixing this issue due to more important issues with the starter I have now fixed it and I'm back on the road so im picking up where I left off, first thing first I decided the cabin air filter might be a good idea to replace while I'm here and this is what I found



Wonder if maybe this is part of the problem

 

While it appears as though the cabin filters were indeed due for changing, I'd doubt that they were causing your previous problems. You'll know once ya put them in !!!

 

use a shop vac to get everything possible out of the filter inlet tube and general area

spiders, birds nest- you would be amazed at some of the pics posted on here

Did you pressure test the cooling system yet? hose clamps loosen over time or replaced and not set right,,, I have even seen OE style rad hose clamps break in half,plop

 

Ok so I replaced the cabin air filter and it still isn't working kinda weird that I can feel the heat coming out of the vents just not a whole lot, and I noticed earlier today a little click and whining sound coming from under my glove box every time I would hit the ac on switch. Those cabin air filters appear to never have been changed lol I really thought maybe they were that bad unfortunately this car hasnt really been maitnenced much I don't think and part of that is why I bouhgt it cause it only has 130,xxx miles however some stuff I'm finding hasn't been done is unbelievable. No I havnt pressure tested it yet Just because I got distracted on the starter problem until I fixed it yesterday and also a power steering issue lol but I think I might have time tonight before I leave work maybe pull it out and see what I got going on here. Also I didn't vacuum the inlet tube tonight I will go back and do that maybe something is caught in it

 

So at my work tonight I attempted to borrow the pressure tester for my radiator however the only one we had was a loaner tool one that was currently out however later this week I'm gonna borrow it and test it unfortunately I couldn't get an answer tonight more information to come as I go. Thanks again everyone who is helping. I'm now focusing all my attention on this problem to try and fix it before the weather gets any colder

 

Hey OlyUA4, if everything else seems to check out.....go back through what ya tried earlier and try it again.
Seems like ya might've been on to something, IMO. Check out Skirmich's DIY fix for the air mix motor !!!

 

Hey I seen his diy for the air mix motor and I was curious about that. It sure sounds like that could be myproblem. ill check it today

 

Ok so I got the air mix controller out of my car today just popped it off when a couple wheels fell out, I just realized on the inside mine looks much different than the one used on the diy and I'm lost has anyone done this on a 99 model? Here's a picture of what I found

 

Any ziners out there who can help me fix this problem now? Think I messed up pretty bad waiting some help of either how to put this air mix motor back together, or where to buy a new one.

 

Check an online Acura parts source or local dealership for more details and pricing on a new part.
Ya may wanna check with your local salvage yard for a similar '99 used part.

 

have you looked online at autozone type stores?
and of course our sponsoring acura dealers that cut us a price break

 

I checked on my computer at autozone the other day and couldn't find anything as far as the air mix motor, also checked on eBay.