I replaced the heater core in my 1989 Golf. If it's the same, you have to lie in a very uncomfortable position (I eventually removed the front passenger seat even to be able to stick my head under the dash) and just start removing the interior trim and plastic vent duct work. Then you'll see a black plastic box, a little shorter than a cereal box, at about the center of the dashboard. Unclip or unscrew the fasteners holding this box to its cover, maneauver the box out from under the dash. Inside is the heater core element, which you can replace (about $30). But, It's such a pain to remove and replace all those dash components, though, I'd make sure it's really a bad heater core (and not something else like one of those blue or green sensors in the engine compartment, mounted on the heater core inlet, before I put a new heater core in. Also, I heartily reccommend a Bentley Publishers service repair manual; they're expensive, but definitely worth it for the do-it-yourselfer. Paul.
Becareful, there are 2 bolts that go through the firewall (should be the same as my 90) mine would not loosen and eventually broke (they are metal embadded in the black plastic box) now my heater core box is being propped up with a hockey puck to align the venting properly, yes a hockey puck, hey I live in Canada, it was handy at the time, and too cold to look for something else.
1988 VW Cabriot
You can find the 1985 VW heater core behind the drivers side kick plate. You will need to remove the kick plate in order to access the heater core.
Which one? The fuse to the fuel pump?
its a pain. you have to take out the whole dash t do it. and it took me 8 hours to get mine done
Just changed the alternator on my 2000 vw golf and now can't get the alternator belt back on - any suggestions?
Allahu Akbar
See Q: How do you remove Steering wheel lock VW golf mk2?
on my 1986 golf 2,(think its the same engine), its located on top of the gearbox.
buy a vw, chiltons, or haines manual or take it to a garage.
Yes, it is a Golf but VW stopped calling it the "VW Golf... GTI". Just as VW didn't call the R32 a Golf (although it is based on the VW Golf and has the same shape and many common components).
This is a common complaint with mk2 Golfs, most of which were fitted with a heater matrix bypass valves to prevent the heater matrix from bursting under certain conditions. These bypass valves can fail, cutting off supply to the heater matrix resulting in no heat. Either replace the valves or remove them and fit a heater matrix from a mk3 Golf. These are stronger units and don't require bypass valves.
Heater plug operation W/L