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87 Trooper Heather Core bypassed?

A guy has an 87 4x4 Isuzu Trooper for sale. It used to have a/c and heat but the guy before him replaced the carburetor with a Weber and bypassed the heater core. The blower still works but if you have no heat to blow then … Is this an easy fix? I can still see the heater core male ends poking through the wall and the bypass hose looping over them. Is it just a matter of making it run through the core? Would that mess up the Weber carb?

Is this an easy fix? I can still see the heater core male ends poking through the wall and the bypass hose looping over them. Is it just a matter of making it run through the core?

Well, yes and no.

It would be easy to remove the bypass hose, and hook up hoses to the exposed heater core…at which point, the heater core would work every bit as well as it did when it was bypassed in the first place.

See the problem?

Something made the prior owner decide to bypass the heater core in the first place…it’s rather likely that “something” was that the heater core was leaking or otherwise malfunctioning. (It seems unlikely that the prior owner went through the trouble of bypassing a perfectly good heater core.)

Heater cores are (generally) in hard-to-access locations, meaning that replacing one is (a) frustrating or (b) expensive, depending on who’s doing the work. At this point, you’ll learn what the prior owner did: that it’s altogether cheaper and easier just to bypass a bad heater core and wear a coat!

That makes sense. Does it make sense that they would bypass the heater core in order to keep a steady stream of antifreeze going to the engine since they were doing a lot of 4 wheel drive all terrain driving? I am hoping that this is as simple as connecting it to the old core but I am going to go back by to see how hard it would be to remove the dash and replace the heater core just in case.

Thanks for the feedback.

The carburetor they have in there is not like anything I have ever seen. It is special one. I wonder what it would cost to replace it with a new one that is meant for the truck and reconnect the a/c and fix the bypassed heater core? That would be interesting. Why fix it if it isn’t broke?

Dude, are you sure what you’re getting into? This is a 23 year old truck that has been used extremely rough. If your trying to turn it into a reliable daily driver, you’re in over your head and will spend a lot of money, money you may not have if your looking at a 23 yo truck, just keeping it running. Chances are, it will not become reliable just because your driving it.

There is no good reason to by-pass a good heater core. There is no ‘improvement’ to engine cooling by by-passing the core but the complete opposite. The heater core can and has been used to improve the cooling of the engine by acting as a second smaller radiator.

With the A/C disconnected, chances are it doesn’t work, either. If any of the hoses the the A/C have been opened or cut, only a complete system replacement will make it work again. If there is no pressurized gas left in the system, I can virtually guaranty that the fix will be expensive, much more so than an '87 Trooper used for off-roading will ever be worth.

And, the Weber carb is much easier to rebuild, adjust, and tune than the nightmare carb that the truck came with. The original carb has vacuum lines, solenoids, and convoluted fuel path designs in an attempt to make them more fuel efficient. A Weber carb is as simple as they get. I suggest you stick with the Weber carb and get a Weber manual to read up on how to maintain them.

Everything you’ve mentioned so far points to a weekend toy that someone is tired of playing with. If your intentions are not to keep it a weekend toy, your wasting your time.

On an 87 Trooper the only reason for the heater core to be bypassed and the A/c to be disconnected is THEY ARE BROKEN, period. Not because they guy was doing hard core 4-wheeling. The Weber carb. is not special, it is just different, and the only reason it is on there is probably that’s this guy had or found real cheap to replace the stock carb. when it went bad. bad. If I were you I would stay away from this like the plague since you can see these problems and who knows what else has been bandaged back together, that you can’t see. This “truck” if you can even call it that is used and abused damaged goods.