problem with blower switch or something else?

[mjc79]

ok the car in question is my 79 regal. previous owner swapped a sbc engine in it but i dont think it has anything to do with my problem. i'll try to explain it in the order this happened.

i tried out the fan switch to see if the blower motor worked and it didnt. so i checked the fuse and it was blown. i replaced the old one with a new fuse and the blower motor kicked on like it should. once the blower took off it sounded like something was shorting it out. the motor wasnt staying at a constant speed, it was acting like it had a drain on it for a split second then was fine and kept doing that constantly. after about a minute of the fan running the light blue wire behind the hvac panel started to get pretty warm so i turned it off. i also noticed the large orange wire on the plugin was lightly burnt but it wasnt warm, just the light blue wire. so i pulled the fuse out and it was pretty toasty warm. i looked at the fuse block itself and where the fuse sets in place it is lightly melted. the only setting that does not work is high speed when selected by the switch. but now my biggest problem is that you can select the fan speeds with the switch and hear a clicking sound coming from the blower motor relay but no blower motor movement.

so does this sound like the blower motor relay is shot or is it something else in the wiring harness maybe? maybe the resistor? i looked the best i could for a bare wire inside and out of the car and could not find anything.

 

[mjc79]

heres a video to explain it a little bit better. when i was talking about the connector behind the glove box i meant to say blower resistor not blower relay lol.

http://www.youtube.com/watch?v=yv-wCXh1RaE

 

[mjc79]

anyone have a guess lol? i was going to buy a new fan switch, relay and resistor for the blower motor but dont want to swap stuff out if thats not the problem. i know a little about electrical but not enough to pinpoint stuff right down to the main problem. i'd swap the relay and resistor out but no one around here has older gm cars its mainly ford country lol.

 

[patmckinneyracing]

I would say check all your grounds first. Honestly it sounds like the blower motor resistor. The blower motor in my 96' dakota was acting the same way you were describing and it was the blower motor resistor. Take that out, as it probably has rust like the one in my malibu did, and either clean it up or buy a new one. I ended up chucking the entire air box because it was more trouble than it was worth and it really helped in letting me get down to the starter wires as the original wires had gotten scorched from the headers.

 

[FE3X CLONE]

The no blower motor on high problem is due to the engine swap I bet. The blower motor on high is powered directly from the battery and doesn't go through the resistor. There is a large red wire with a connector over by the HVAC system under the hood that I bet is unhooked.
I've done it in the past when swapping engines and forgot to hook it back up.

 

[mjc79]

thanks for the help guys. after messing around with it for about an hour i think i got it narrowed down to the blower motor resistor. i did find a body ground undone so i hooked that back up but still didnt do anything. so jumped the fan motor directly from the battery and it took off so it ruled that out. but i was messing around with the blower resistor plug and then messing with the switch then all of the fan settings worked even on high. but now all it has now is high and also the little blue wire is not getting warm anymore.

BUT, when its not in the high position or off it does this to the fuse in about 10 seconds

 

[mjc79]

The no blower motor on high problem is due to the engine swap I bet. The blower motor on high is powered directly from the battery and doesn't go through the resistor. There is a large red wire with a connector over by the HVAC system under the hood that I bet is unhooked.
I've done it in the past when swapping engines and forgot to hook it back up.

i checked for that large red wire and it goes from the blower relay back to the gang plug on the firewall. i assume it goes right into the fuse box. the only other large red wires that were in the harness were for the alternator wire and some going to the starter.

 

[nawlins-tim]

I recently had problems with my blower not working properly. First I traced all the wires pertaining to the A/C system by useing the diagrams on MALIBURACING.COM SITE. check it out and search for wiring diagrams in the tech section or just do a search on there site.
Anyway , On my ELKY I removed the resistor and when I saw that as long as the terminals are all sound (and connected)they really can't go bad , unless they get too rusted and break-off. So I went to the relay. When I looked at those Diagrams I told you about it made sence to just replace it for the small cost at AUTOZONE. After doing so , BOM, I got air flow. It was a 12 dollar fix. Now my compressor wont come on unless i jump that preasure switch.
But that another thread. Thanks.
THE MORAL OF THE STORY, CHECK OUT THE WIRING DIAGRAMS ON MALIBURACING.COMhttp://www.maliburacing.com/wiring_diagrams/FourSeasonAirConditioner.jpg

 

[mjc79]

thanks for that info man. i went ahead and replaced both the relay and the resistor. everything is all good now with no wires getting hot or melting of fuses lol. thanks again.