The heat hasn't worked in my Prelude since I bought it. It's a 1992 S coupe. The fuse under the hood is still good. I want to check the relay in the dash fuse box (image below) but I don't know how to remove the relay. I would have assumed it just pulls out, but I can't, for the life of me, get the damned thing out. Is it supposed to just pull right out or do I need a tool? Also, how do I go about testing it once I have it removed? I mainly just don't want to break something in an attempt to force it out, and I want to get my heat working again. Ohio winters tend to be pretty harsh and I need my heat. Only thing I have right now is an auxiliary heater to defrost the windshield. I've been told that the BB4s are notorious for having the climate control units fail too. Any help and info is greatly appreciated.

 

I'm not positive, but I thought it pulled right out. Anyway, here is how you test it once it's out.



There's a nice flowchart in the manual if you're not sure that the relay is the problem. Flowcharts and a multimeter are my 2 best friends during honda electrical problems...

 

thanks for the reply, man. i do have a manual that i downloaded, but it doesn't have the clearest instructions. i replaced the relay and still nothing, so now i'm trying to remove the blower unit. i've reached a snag with that as well. i have all the screws and what not removed that hold the evaporator in place, but it's still staying in there pretty solid. it looks like it's still hooked on where it goes into the firewall, I just am not sure what I need to do to remove that. the manual doesn't explain it. just says remove the 4 screws, a bolt, and 2 nuts, and remove evaporator. any words of experience, anyone?

 

did you check your thermostat. its alot easier to replace than the blower box

 

nope, i have not checked the thermostat. i do think it needs replaced, though. If i leave the car sitting idle for too long it will want to overheat. would a bad thermostat prevent the heat from responding? i figured it would be all electrical, but then again this is the voice of inexperience speaking, so I really don't have the first clue. everything i've done to this car so far has been learned in the past couple days. only thing that still responds on the control unit is the rear defrost button. if i flip the fan switch to on, nothing happens at all. relay is good, and from what i can tell, the wiring is all good too, so i assume either bad blower motor or bad control unit. my plan was to access the blower motor so i could jump it to see if it was still functional.

 

I'm leaning towards the control panel, mostly since it's happened to me.. and a lot of other prelude owners from what I hear.

As for the EVAP, those are refrigerant lines that are making it feel stuck to the firewall. You'd have to get the system vacuumed and then recharged to completely remove it. You should be able to just test the blower while it's still in though.. right? The electrical connectors are on the front of it from what I remember..

 

Thanks man. I'm at a stand still right now. Never have any daylight to mess with it outside, plus I work erratic hours. I'm also having troubles getting the control unit, itself, apart. I have it mostly taken apart, but I can't remove the circuit board. it gets caught up on these two little round plastic pieces on the top part of the circuit board. I was reading a write up on how to disassemble this and it says the board SHOULD slide right out, but it's clearly getting stuck on those two plastic pieces.

These

 

those are just the bulbs that light the front display up. just put a flathead in the slot and spin them then they will be ready to drop out then you can pull the cicuit board forward and out