Heater Blower

[Laurent M.]

[Edward J.]

Re: Heater Blower

Laurent, yes in ignition position , Assy. position I do not have a wiring diagram in front of me, so I am not sure. If no one can answer this I can get you a answer later after work. Why are you asking this? something up?

[Laurent M.]

Re: Heater Blower

Thanks Edwards. English is not my mother tongue, I am french guy with just a school english level but I will try to do my best to explain you the problem. Before I worked on the car the blower was running but the AC no. Because the harness in the engine bay was very poor I have decided to replace it and the AC harness too, and refresh all the AC component in the engine bay.
I have also remove all the dash to check the AC system components and discover that bubba(s) had really made a good job in this car..).
My car is an early 70, I found that the dash harness wiring was a 1971 ( because 2 additionnal relay located in the AC duct box).In fact I believe that all the AC system come from a 71 car. Anyway, I wouldn't replace it because its condition is very good.there is no big difference between the 70 and 71 dash harness and it wasn't difficult to plug it the AC control harness ...But the fan don't start that means there is something wrong somewhere.
I'am confident to find the problem.

[Laurent M.]

Re: Heater Blower

Test again this evening and I can confirm that the blower works with ignition on and not assy position. The reason I tought that it didn't work was simply. the fan switch was is position max but this position doesn't work, all others positions are ok. I suppose I've now to check the AC relay or the blower ,heater resistor no?

[Edward J.]

Re: Heater Blower

Laurent, there is a fuse located in the drivers side inner fender wheel, its encased is a white plastic holder that has a twist style release. This is for the high speed blower relay.

[Laurent M.]

Re: Heater Blower

Thanks, just test this 30A fuse is ok

[Edward J.]

Re: Heater Blower

Okay go to relay on heater box. the relay connector- wiggle the connector with the high speed on and key on see if t the blower starts to work, have seen the connector's get hot, the orange wire on relay make a bad connection.

[Laurent M.]

Re: Heater Blower

I have wiggle the connector and the relay isn't hot , it still not working

[Edward J.]

Re: Heater Blower

So next unplug connector and see if orange wire has power, and check if black wire has a ground, I do not have a diagram in front of me and am working from memory. MY 72 had the plastic connector melted and the orange wire with a bad connection. if you take a test light and clip one wire on to ground and the other to the orange wire it should light up with key on and blower on high speed.

[Laurent M.]

Re: Heater Blower

OK connector is unplugged and power arrived at connector ( FYI is a new ac harness ) but it seems that there is a problem with the black wire (ground) it seems that the relay is not correctly grounded. I have connected a wire between the ground terminal of the relay and a good ground and I can hear the relay "clicked" when i ground it but the blower doesn't run at max speed.
I have to check tomorrow the black wire , and if it's still bad that should be the relay

[Edward J.]

Re: Heater Blower

Do you hear the relay click with everything hooked up and blower switch on high speed? When relay clicks there should be power to purple wire at blower motor. it does sound like relay, but check the purple wire for power. I think the ground goes from relay to blower and branch's off to some where maybe to starter?? engine block to transmission bolt.

[Laurent M.]

Re: Heater Blower

thanks I will continue tomorrow time for me (in France) to stop, I will keep you inform

[Laurent M.]

Re: Heater Blower

Hi Edwards.The problem is fixed. Let's me explain to you.
The ground were ok, the purple wire has power normal because the motor is connected at this wire and works at low speed;
then the problem was the relay. one previous owner has mount this relay on the AC box with the connectors up. I ve remove and dismantel it and saw that it was plenty of rust dust inside, during the time a lot of water gone inside.
I ve clean as much as possible, reinstall it in the car, all speed are work well. I ve order today a new one.
I really want to thank you for your good advices and knowledge. I've the car for only 6 months and learn a lot with reading the forum. I ve done lot of work on the car by myself and the next job will be after the summer to replace the edelbrock carb+intake by original part. I've on the shell a correct period rochester carb ,but to be honest I am a bit affraid to rebuilt and tune it to get good performances. Will see
Laurent

[Edward J.]

Re: Heater Blower

Laurent, If you have patience and are well organized, set the carb on a clean piece of paper and this task will start out on the right note. lay everything down in its order as you dissemble carburetor,If it was in some sort of working order a simple rebuild kit should be all you need. myself being a mechanic all my life I have experienced this hundreds of times. And what I have always liked is to find out what makes things tick. I guess this goes for most of Corvette owners. there should be a instruction sheet in the rebuilding kit to aid you and give you the spec.s.

[Laurent M.]

Re: Heater Blower

Do you know where I can buy a good quality rebuilt kit for my quadrajet?