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Isuzu Trooper Heater Core

gruntbugglygruntbuggly Member Posts: 4
edited August 2014 in Isuzu
HEllo. I've gone to the trouble of completely removing the dash from my 93 Trooper in order to change the leaking heater core. Now, I'm looking at the white ductwork that houses it, and can't get it open. I really don't want to break anything, but with all the (visible) screws out, I can't seem to get it apart. The Chilton's book has no pics at all, and basically none of the dash diagrams matched my Trooper completely. I think I ended up using parts of each diagram to get it out. Any good sources for this? Thanks in advance!


  • atfdmikeatfdmike Member Posts: 414
    this is all I could find, hope it helps. There might be a sealer that is keeping the case from splitting. Good luck.

    1993 Isuzu Truck Trooper (4 Door) V6-3165cc 3.2L SOHC (6VD1)
    Vehicle Level Heating and Air Conditioning Heater Core Service and Repair

    Service and Repair

    Removal Procedure

    On models equipped with airbag system, refer to Technician Safety Information for system disarming and arming procedures.
    Disconnect battery ground cable and drain cooling system.
    Remove rear seat, then disconnect heater hoses from rear heater assembly.
    Remove heater assembly attaching bolts, disconnect blower motor electrical connector, then remove rear heater assembly from vehicle.
    Remove clamps and remaining heater hoses.
    Disconnect blower resistor wiring harness, then remove attaching screw and resistor.
    Remove seal, then the left and right support brackets.
    Remove attaching screws and front duct assembly.
    Remove case retaining clips, separate case, then remove heater core.
    Reverse procedure to install.
    On models equipped with airbag system, refer to Technician Safety Information for system disarming and arming procedures.
  • jkungjkung Member Posts: 1
    Hi: I just joined this group hoping to participate in the discussion. I am in the process of changing my 93 Trooper heater core . Have you found the info that you needed ? I have the factory service manual which is very detail and useful.
    I am however get stuck on the removal of the two water hoses connected to the heater unit outside of the firewall. Do I need to get the clamps from under the vehicle ? I can see/feel the clamps but do not have ebough room from the top to disengage the clamps/hoses.

    The heater core assembly with the "White Plastic housing" is made up of three pieces. If you require further details, please email me and I will send you the details.

    For now.. those two hoses are holding me back. I have removed the dash and attachments from the inside already.

    BTY, where did you buy your new heater core ?


  • gruntbugglygruntbuggly Member Posts: 4
    I did finally work this out on my own. I never got a good set of disks for the Trooper, but I finally got "bloody-minded" about it and dove in!

    The hoses from the engine to the heater core - I undid the motor side connections first, then got some ridiculously long needle nose pliers (cheapo ones from Sears Hardware) to undo the clamps from the heater core itself. This wasn't impossible from the top side, maybe your clamps are on crooked, or the wrong way around! BTW, a shorter handled set of angled needle nose pliers was needed to get the second (lower) clamp off.

    I ordered the heater core from a place listed on There were several available, I got one from a salvage place in Michigan (eww, I'm from Ohio!), but it was in pristine condition.

    A couple side notes -

    1) I did have to take the white air handler apart to get the old core out, and needed to keep it apart to get the new core back in. It's a pain, but it did work.

    2) There are two small hose pipes that stick through the firewall that need to be removed from the old heater core and attached to the new one. TRY NOT TO BREAK THEM!!! I did crack one of them trying to get the new core into the car, but I epoxied it, put electrical tape (just a little) around the outside, and prayed that the hose clamp could keep it all together. (It has for over a month now!)

    3) To me, the hardest part of getting this back together was getting the new heater core back into place with the pipes through the firewall. The insulation on the outside of the firewall will fight against you, and the interior housing for the air-conditioner coil will be in the way. Loosen it all up and nudge it as far to the right as you can!!! It will eventually push through. Once it's back through and in position, I put on the front of the white air handler, and got the hoses connected up.

    4) Watch for this!!! Once I got it back together, I tried to drive it to work the next morning. On the way, I saw that my temp was rising way up! It turns out that my thermostat was stuck shut. Since the heater core is in the loop with the engine, it is my nagging suspicion that this caused the heater core to blow in the first place. I had steam pouring out at the passenger seats floor! The thin aluminum in the heater core was the easiest place for the steam to blow out. I'd at least check this, or just replace the old thermostat while you've already got the system drained. A new one was $13.00 at NAPA.

    Good luck! Post again if you have more questions! Good Luck!!! chris
  • arloiarloi Member Posts: 4
    Guess that I'm in for a long job on this one. See by other post that the dash is being removed. Is this a must? I have taken off every clip and nut in sight and still haven't move the heater. thanks for any tip on this. I have yet to find a new core. will try the that was refered to in one of the post. Notice that a flaper arm was broken that need to be replaced. Maybe can find one at a salvage yard. Thanks for any tips and advice.
  • gruntbugglygruntbuggly Member Posts: 4
    Yes, the entire dash needs to come out. At least on the '93 Trooper. The heater core is never supposed to need replacing, so there's no shortcut to doing it. Yes, I'd check local salvage yards as well. You'll probably need to get the whole air-handler body from the salvage yard, and likely have to go there and remove it yourself. Still, it'll be good practice! Good luck! chris
  • arloiarloi Member Posts: 4
    Not knowing what to expect, when I get the hearter core removed. Is it possiable to have it repaired. Or would that not be recommended. I have located one at a salvage yard, I would have to remove it and would not know the condition of it. Price is right $10. The guy told me it fits 84 thru 88. Isuzu dealer quoted me a price of $294. for new one.
  • arloiarloi Member Posts: 4
    Well, I have it out, and can see that it has a plastic fram with metal cores and fins. Don't think it can be repaired. Unless there is a very good glue made for it. It dosen't look like it is in too bad of shape.
  • gruntbugglygruntbuggly Member Posts: 4
    Maybe a radiator place would fix it, but I doubt it. Good luck! Cheer up! You're half way done!
  • boxtrooperboxtrooper Member Posts: 843
    A really goos radiator shop might be able to make you a new one using just your end caps or even fabricate new end caps also. Its worth asking.
  • arloiarloi Member Posts: 4
    Went down to a pic-and -pay salvage yard. Found an 88 trooper with a heater core. Taking a chance with it, but only $10., maybe I will be lucky. Will go have it tested before I install it. Also found out the 81-82 chev luv used the same core. The salvage yard can give a lot of info, in regards to what different vehicle use the same parts. Also picked up a couple of dash vents for $1 each. I'm not proud. They look better than my broken one. Now when the sun shines again, I'll have something to do again.
  • mthanermthaner Member Posts: 1
    I have a 90 trooper which I purchased with out a heating core installed, supposedly leaked.., thought it would be no problem to replace.. I cant even find one for a 90, with out paying over 400. and waiting several weeks to arrive from Japan.. is there a substitute ( Mitsibushi Montero ) part I can use, I even heard maybe Chevy S10, any help would be apperciated...
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