Go To Bottom

Printable Version  
Author: Subject: How to replace Heater Core in a 91-94 Tercel (Now with photos)
Junior TO Member

Posts: 206
Registered: 17-10-2005
Location: Killa Kweenz, NYC
Member Is Offline

Mood: No Mood

[*] posted on 4-12-2005 at 07:39 PM
How to replace Heater Core in a 91-94 Tercel (Now with photos)

**** Iight folks, when I first wrote this I should have taken photos but now being I was painting interior I thought I'd take some flicks and post them now. Not all was taken but what I could rememeber. I hope this help. ****

I wanna try to keep this thread to the subject. I used Haynes Manual as reference. Book # 92085 / ISBN 1 56392 106 5. Please excuse if I don't use correct terms. trying to explain as easiest as possible.

My car is automatic, has A/C and no airbags so this information is based on that. Heater core was from Dealer.
reason for changing core was when heater was on, vents emitted antifreeze.



so lets begin,

1) have refridgerent discharged from car by certified Tech or someone with experience and equipment. When at home leave the front wheels straight before starting job



4) engage e-brake and wheel stoppers

* remember I have an automatic

5) use shifter override and pull shfiter all the way back

*note: use container for all removed screws and bolts

6) remove face plate of radio console (clipped on). disconnect rear defroster. Remove whole stereo console. 4 bolts. pull unit out and disconnect lighter as well as all removeable plugs. *note" if you have to label wires, do so, i did. My car has a system so i'm not gonna go into the removal.
my setup and your setup are different. Any RCA's or exposed wires from removing stereo you should tape up (electrical tape of course). Also release plugs mounted (possibly bolted on for grounding purposes) to the metal frame. *note: you can place bolts back on its mounting point as a reminder of reinstallment

7) remove glove box and panel under steering column. release hood before removing panel under wheel. *note: some bolts are covered by caps / the panel under steering column has a clip attached and a little tug may be needed (located left side, where it meets door. and glove box is in one piece it's not seperate from panel surrounding it. The book says panel under steering wheel has two screws for hood release cable removal, my car didn't. I had a clip on mine but couldn't get it off. I actual did the whole job with panel held by cable. hence releasing the hood at the begining of this step.

8) remove center console and e-brake cover. e-brake cover comes out before center console.

9) pull out knobs off of climate control. remove face plate of climate control (just pull out) not too hard you have to pull out a/c button as well

10) remove steering column cover and steering wheel. there's a screw underneath the column. remove both horn portion and screw that holds in wire. Remove steering wheel backplate held in by 4 screws and one big nut that hold the wheel in place. remember the wheel was left straight before starting job so reinstalling wheel will be easy. remove screws and nut. Wheel might not come off easy so wiggle it a bit while pulling out.

11) remove signal and wiper component. (forgot what it's called) that's attached by three screws. pull out passed mount and let it just hang there

12) now with underside of dash exposed, underneath the steering column unscrew cabin fuse box and remove vent that runs under column which is held by a screw on the left side. also unplug any plugs mounted to metal.

13) back to the climate control. follow control cables. there are 3 cables. one that goes to the left of and one under vent box. the third goes the left side of heater blower (the white unit all the way to the right under dash. to remove cable, using switch of climate control extend cable you're working with to pull off of mounting point and take cable off of clip. with face plate removed it'll expose 3 screws, remove them. and the trick with the removal is the the right side gets pushed back sliding the left side behind dash *note: if you want, label your cables

14) removing bezel where the cluster dimmer and hazard switch are. undo the 2 screws at the top. and pullout around switches they're held in be clips. Remove it enough to get you hand behind switch to unplug connecter on both sides.

15) remove cluster by undoing the 3 screws and/or bolts when done reach under dash on the right side of column and feel for speed cable that's attached to cluster. feel for notch on plastic end of cable where it meets the cluster and press and pull out. now that give you some space to remove the 2 clips attached to cluster. to take cluster out, pull bottom out first.

16) remove clock from dash, lift and pull out. then unplug connecter

now the fun part. the dash board

17) remove pillars they attach to the dash. they're held in by clips, just pull off. if memory serves me right, the only thing holding in dash are 2 nuts and 1 bolt that are behind cluster. remove those and check all around under dash to see if there aren't any wires clipped onto the dash. unclip all mounting clips. using needle nose pliers helps alot to release clips. if there are plugs that are bolted to dash behiind cluster unbolt them. I can't say mine will be the same being I had an engine swapped. after all that said is done, lift the dash a bit and pull out. dash is held in be 5 clips in the back. Do this with care for the simple fact you don't want to pull anything important out. If you feel a slight restriction, stop what your doing and check to see what is caught. this too needs a little tug to remove.

A = the black connector in the background

now that you car is naked inside. go outside in engine compartment

18) drain radiator out. some radiators have drain plugs and some you have to remove a hose. I have a drain plug, yours might be different. check specs of your radiator

19) undo hoses connected to your heater core, there may be little antifreeze in the hose, a little may spill. remove what the book called "grommet" the rubber piece surrounding heater core link.

20) now your A/C, 2 pipes (refridgerant line) going into passenger side firewall you'll need 2 wrenches for this use one wrench to hold bolt closest to the fire wall (labeled A) steady/leverage and use other wrench to loosen connection (labeled B). stand at the side of the car and pull towards you. use caution because you don't want to brake any pipes. do this for both connections and remove rubber piece or "grommet".

back into the car.

21) remove the 2 metal center braces, both have 2 nuts at the top mounting points. left side has 2 bolts at the bottom and right side has 1 bolt at the bottom. Of course disconnect plugs.

22) remove vent port in front of vent box. that has 3 screws. one is mounted to the reinforcement support and 2 at the lower corners of piece. also remove vent behind reinforcement support above vent box. that's held in by 1 screw.

23) to remove a/c unit, unplug any connecters and magnectic clutch relay. (the cylindrical unit screwed on by bracket)unscrew every bolt and nut top and bottom holding it in. pull it out and notice the drain hose at the bottom that'll come out too. to prevent dirt from entering unit cover connecters inside engine compartment and the a/c unit itself. when under hood, this is your chance to replace o-rings on 2 a/c pipes. also check insulation for any wear. if so here is your chance to replace it.

24) now removing heater unit, undo all nuts and bolt around unit. remember that the heater core pipes are hooked. lift unit a bit and pull out top. *NOTE: there's still a bit of antifreeze in the core. a little may spill

25) heater core is held in by 2 braces unscrew them. the heater core then will slide out from the top. here is your chance to clean all the vents out from dust and whatever else. Reinstall heater core and reverse all that was said.

Testing your job will take the assembly of heater unit, a/c , dash, climate control cables,and all plugs except radio console. recheck all taped wires before reconnecting battery. start the car and check/smell for any leaks and then crank the heat. if all is good shut car off and DISCONNECT BATTERY


27 continue reinstalling everything.

Well these were my steps that I've taken. Edits will be made if I see I vaguely wrote something. or confusion point. I hope this helps


[Edited on 25-7-2006 by OPMNYC]
View user's profile View All Posts By User
TO Patron


Posts: 2094
Registered: 19-7-2005
Location: HOUSTON!
Member Is Offline

Mood: Turbo Withdrawals.

[*] posted on 17-8-2006 at 02:57 PM

i cant believe i never saw this. this is valuable information. score!

This Space for Rent.
View user's profile View All Posts By User This user has MSN Messenger
TO Newbie

Posts: 49
Registered: 2-12-2008
Member Is Offline

[*] posted on 28-3-2009 at 09:03 PM

wow, how about you come to my house and I pay you to change mine.
View user's profile View All Posts By User
TO Newbie

Posts: 40
Registered: 6-4-2010
Member Is Offline

[*] posted on 14-9-2010 at 10:09 PM

Yikes and I thought a Head was involved.
View user's profile View All Posts By User
Junior TO Member


Posts: 480
Registered: 28-3-2010
Location: Hesperia ,California
Member Is Offline

Mood: Meh ^_^

[*] posted on 6-12-2010 at 11:14 PM


wow, how about you come to my house and I pay you to change mine.

If your in california, I can do it lol, and without pulling the whole dash off XD

EDIT: had a typo

[Edited on 7-12-2010 by bmxfreakrider]

View user's profile View All Posts By User
TO Newbie

Posts: 1
Registered: 2-10-2017
Member Is Offline

[*] posted on 17-10-2017 at 04:39 PM

Old thread, but helpful. I replaced my 1992 Tercel (w/AC) heater core last week. Anyone who says they can do the job without removing the dash must have a very different Tercel than mine. I did not have to break the AC system and I did not remove heater control cables. AC system had enough play (about 1 inch) for me to be able to separate the heater and tilt it to remove the heater core. I would guess the job took 8 to 10 hours. Toyota wanted about $350 for new core, if I remember right, got one about two years ago from RockAuto, they still list them at $53.79. Winter is coming and I was sick of the smell of anti-freeze, so I finally installed the core I purchased about 2 years ago. Toyota would have wanted more than the car is worth to do the job. I rebuilt my engine 5 years ago and it is still running well. Also installed a 5 speed transmission at that time, way better than the old 4 speed. Maybe someday I will install an early double cam distributor motor for a 25% power increase. Keep on turning those wrenches yourself and screw the stealer ships!

Brad Zeigler
View user's profile View All Posts By User

  Go To Top

Powered by XMB 1.9.11
XMB Forum Software © 2001-2010 The XMB Group