How do you repair the heater - fan blows air but never gets warm or hot - in a 1993 G20 van?

Answer 1

Incomplete Answer from RFXK (2/7/07): If you're real lucky, you're just low on coolant. Check to make sure that the reservoir is full, and also pull the cap off the radiator and make sure it's full too (sometimes the tube from the reservoir to the radiator is clogged, so the reservoir is full but the radiator is actually low). If both are OK, it may be that the radiator system needs to be flushed. If the radiator fluid looks and smells nasty (brownish-green instead of bright green), this may be the problem. Plenty of products available to do a radiator flush. Do it right and it may clear up the problem. If the radiator fluid looks good, or if it looked bad but a flush didn't help, then your heater core is probably shot. I'd say that (most of the time) this is the real problem. If you don't know what you're doing, go get this done by a pro. Yes, it's pricey. If you want to tackle it yourself, and you have a garage to do it in so you don't have to freeze to death, get a good service manual that's specific to the G vans, and proceed carefully. Remember that radiator fluid is irresistable to dogs, cats, and other animals, and is a deadly poison for them, so be sure to keep it enclosed, and dispose of it properly (most filling stations will take it - many are required to by law, depending on the state where you live). Good luck. i had this same problem and just had to sort it out, i found the same problem and to remedy it, I removed the long heater hose from the rear of the engine (the one that leads to the heater in the engine bay) it runs along the right hand side of the engine i found this was solid with rust and gunk where the cooling system had never been flushed, i also removed the hose the runs from the radiator to the heater and well (leaving it connected to the heater) with theses two hoses disconected i used a garden hose to flush through the heater pipe still attached to the heater this flushed out all the muck in the heater matrix if you can flush through from the other hose connection as well then refit all pipes making sure clamps done up tight. refill radiator and run engine when reaches temperature should all work fine. remember to check radiator fliud after engine cools as well and top up if needed p.s. the heater hoses are the two black rubber ones NOT METAL ONES if you have aircon best of luck post if any other problems arise