Still having a blower motor relay issue

[rainyraven]

Hello everybody..
I put up some new pics of Roxy.. she's making head way

But I'm still scratching my head so I replaced the whole wiring harness for the ac/ heater on my truck.. new relay new motor new wiring

I checked it on the parts truck I got a hold of worked fine took it off the parts truck hooked it up and now I'm right back too my problem.

1. I checked power to relay power is there.
2. if I unplug the relay and just jump power from the main red wire of the relay fan runs fine. of course I have no control over the speed then.
why does it not send the power from the relay to the motor? anybody have this problem before.. HELP ME I'm going nucking futs
Thanks

 

[crazy4offroad]

Have you replaced the blower motor resistor?

 

[rainyraven]

^^ is that on on the outside of the box.. or is there another one on the inside ? if there is one someplace on the inside that could be my problem but I've replaced everything on the outside of the box also the box.. but the ac side is not powered never has been before.

Its just strange to me that I'm getting power to the relay but then it just goes someplace else almost like the relay is sending the power back to the cab.. *shakes head I don't even know if thats really possible is it?

 

[crazy4offroad]

It's on the outside. When you jump the relay are you bypassing or actuating? Meaning are you jumping main power-in over to fan-out, bypassing the relay? Or are you jumping switch in to ground causing the relay to actuate? On the relay, you have power in (from power source, like junction), power out to the fan, a ground and a switch wire in. Check your ground and check your switch wire in. But if you're able to jump switch wire in to ground that should kick the fan on. If not, check those 2.

 

[rainyraven]

ok Thanks for the help.. Id believe I'm jumping main power in to the fan when I get fan to run.
on the relay if I prob the main power wire its got power, but the other wire off the relay the one that hooks up too the fan power out to fan from relay* is dead. hope that helps explain what I got going on.*thou I think you already understand my issue*

Thanks again for the help.. I'm not the most electrical savoy but I'm learning.. I have a slow learning curve on electric stuff for some reason.

 

[crazy4offroad]

I understand what you're saying. How many wires go to the relay?

 

[rainyraven]

Right On Thank you very much I got it figured it thanks too your help.. You ROCK MAN!

 

[crazy4offroad]

Glad to be of help, but what did it turn out to be? This thread might help someone in the future if your fix is posted.

 

[bucket]

My '79 has some kind of secondary blower switch on the back of the HVAC controller. It's on the fritz too. The blower works on all speeds, but only on one or two of the settings (heat, AC, vent, defog, etc.) will let the blower work. It works fine on heat, but occasionally it needs that slider knob jiggled to let the blower come on. I'm planning on taking the HVAC controller out and bypassing that troublesome switch somehow.

 

[rainyraven]

My '79 has some kind of secondary blower switch on the back of the HVAC controller. It's on the fritz too. The blower works on all speeds, but only on one or two of the settings (heat, AC, vent, defog, etc.) will let the blower work. It works fine on heat, but occasionally it needs that slider knob jiggled to let the blower come on. I'm planning on taking the HVAC controller out and bypassing that troublesome switch somehow.

That sounds exactly like my truck when I got it..

So for me I could never figure out why my truck only work on one or two speeds..
then finally it just stopped working all together *it was also on a toggle switch when I got the truck.

So yesterday I found the brown wire coming from the fuse box that goes to the the fan switch was dead. instead of dealing with pulling the fuse box out,
I unhooked that wire and used a constant power. Orange wire to replace it.. and now I have all speeds and when I turn the heater too off it turns off!

Keep in mind that my truck came too me with a lot of wiring reworked.. but I'm sure this same concept will work for you too, you could just run your own constant wire off the fuse box with a spade and then another spade into the brown wire on the fan switch.. hope this helps you and anybody else that had this problem