[RESOLVED] Heater Relay fuse keeps blowing

[BestMakeWay]

Hi guys, first of I have to say there is soooo much information on this boards I can almost do anything on my car with out having to go to mechanic. Its great!!

But, Im having a problem with my heater. I have searched and read through a few posts about a simillar problem but nothing quite like mine.

So as the tittle states my 10A heater relay fuse keeps blowing even when the fan switch is in the off possition. I just have to have the fuse in and the ignition on. So I dropped the glove compartment box and took out the chiltons manual. I had read in other posts that theres a common problem with the resistor. So I unpluged three connections behing the glove compartment and turned the switch to on with a good fuse. Fan turns but only works on hi. So I started to plug the connections one at a time and fan worked on all speeds, but when I plugged the "Automatic Compressor-ECM" than the fuses started to blow again at any speed and even on OFF.

So obviously the fan works, the resistor works (all speed worked without the "Automatic Compressor-ECM" plugged in), and I dont want to take anything apart that I dont have to and I'm stuck. Can any electronic guru or a person with the same problem help me out PLEASE?

btw: The car is a 1998 Eclipse GS - and its been parked for a while with a bad heater core, never any problem with the fan though and one week was working the next it wasnt (I usually try to turn it on every week.) So I changed the core (myself thanks to this forum) thinking it would just fix that but it hasnt.

 

[96TurboGS]

Have you checked it thoroughly for shorts? All the PCM does is grounds (logic level 0) the relay, in turn activating the fan. The relays always has a load of 12v. Check for old rusted/busted/stripped wires around the fuse box and wire harness. Heat is what kills fuses. Maybe there's a 12v wire touching a ground/another wire somewhere in there??? Look hard enough you will find it.

 

[BestMakeWay]

Well, remember that the problem was there before changing the heater core and its still there after.. so I dont think its a problem of a wire shorting out some where, rather a problem with whatever that "automatic compressor-ecm" is which I cant find much info on in the chiltons manual. Can anybody tell me what that does and if there are any relays inthere. Maybe some antifreeze got in there and shorted something out. thanks

 

[Defiant]

Check this:
http://www.dsmtuners.com/forums/pro...ntrol-resistor.html?highlight=heater+resistor

 

[96TurboGS]

I read the post wrong thinking of the radiator fans, when you were talking about the interior fans. I remember a case like this a not too long ago on 2gnt, here is the circuit schematic posted by mike on 2gnt to further help you find your problem around the resister pack.

 

[BestMakeWay]

Check this:
http://www.dsmtuners.com/forums/pro...ntrol-resistor.html?highlight=heater+resistor

Thanks read that already but will re-read to make sure I didn't miss something helpful.
thanks again!!

I read the post wrong thinking of the radiator fans, when you were talking about the interior fans. I remember a case like this a not too long ago on 2gnt, here is the circuit schematic posted by mike on 2gnt to further help you find your problem around the resister pack.

Thanks for the help... Ill try to decipher that whole picture and I guess try to trace every wire back there even if I have to take it all apart again. Ill keep ya posted.

 

[99GreenEyeZ]

i know im a new member and all, but i knew after your first sentence in your explanation "even with the switch off it blows the fuse" immediately indicates a short, or a bad switch, id try to bum a friends switch to test it out, or get out your volt/ohm meter and switch it to ohms, with the ignition off. and check for continuity on your fan switch circuit. good luck.

 

[VelocitàPaola]

i know im a new member and all, but i knew after your first sentence in your exsplanation "even with the switch off it blows the fuse" imediatly idicates a short, or a bad switch, id try to bum a friends switch to test it out, or get out your volt/ohm meter and swithch it to ohms, with the ignition off. and check for continuity on your fan switch circuit. good luck.

It doesn't necessarily indicate a bad switch, but definitely a short somewhere.

OP, which fuse are you talking about? The 10A fuse (#13) in the diagram above?

 

[BestMakeWay]

Yes it is the 10a one on the inside fuse box. So I actually have norrowed it down to what the chiltons manual calls the automatic compressor, because everything works fine (exept for the A/C) when this part is not plugged in. As soon as its plugged in, fuse blows. So, I have a beautiful saturday planned at the local junk yards to see if I can pick one up or two and see if it fixes the problem. I will make sure to post if it does just in case somebody else has the same problem.

 

[BestMakeWay]

Got the "automatic compressor-EcM" in today from ebay, replaced, and the problem has now been solved!!! Im soooo happy. Actually the part was from a '96 Dodge Avenger but the numbers matched up and although the inside wasnt the same it defenetly worked and now I have A/C and no more blown fuses. Thanks for all your help guys and I hope this thread helps someone else in the future.

 

[redlineclipse]

Ok I am having the same problem that you mentioned. I keep blowing the 10amp heater fuse. What is this part that you replaced? The car's ECM? or do you mean some kind of ac part. I'm sorry but I searched that part and only found the actual car computer. Please help it 101 here. Thanks in advance