Topic: Blower motor fan running when off
in Forum: C3 Electrical
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Hi Guys,
I am having an issue with my 1977 corvette, well I think it is an issue.. My blower motor is running on low speed as soon as I turn the key to on. This is with the blower switch on the off position and heater/ac on off. I can use the blower motor switch and put it to low/med/high and everything works fine but again the blower motor is running on low speed as soon as I turn key to the on position.
I took a look at the schematics and if I pull the tan wire going to the blower motor resister I get normal operation, low/med/high and the blower motor is not running on low speed with the switch to off position. But the tan wire according to the schematics is going to 12 V to the fuse box and is suppose to be that way so I am kinda stumped here.
Any insight?
I am having an issue with my 1977 corvette, well I think it is an issue.. My blower motor is running on low speed as soon as I turn the key to on. This is with the blower switch on the off position and heater/ac on off. I can use the blower motor switch and put it to low/med/high and everything works fine but again the blower motor is running on low speed as soon as I turn key to the on position.
I took a look at the schematics and if I pull the tan wire going to the blower motor resister I get normal operation, low/med/high and the blower motor is not running on low speed with the switch to off position. But the tan wire according to the schematics is going to 12 V to the fuse box and is suppose to be that way so I am kinda stumped here.
Any insight?
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On my 78s and 79s there is no off for the blower, it always runs. Does your control show an off or just low,med,high?
Just part of the ventilation system as there are no floor vents in AC Vettes.
I'd think the 77s are the same since that was the first year for the new console and console mounted controls.
Do you have an owners manual? It would be mentioned in there.
It shows Hi/Med/Low and off. I don't own the owners manual but I guess I can live with it or just disconnect the brown wire going to the blower resister.
Was really just trying to find out if other vettes are the same way..
Was really just trying to find out if other vettes are the same way..
On some of the GM's the blower motor runs at a low voltage, Gm's idea was to keep the fan at a slow run from seizing due to non use. I have put a switch in some to stop this and still be able to use the fan when needed...this is done by...
removing the blower fan fuse from the fuse panel
attach a fuseable wire to the hot side of the fuse socket in the fuse panel, you can use a flat spade connector attached to the wire
run this wire to a good 20 or 30 amp micro toggle switch in a holder neatly attached under the dash out of sight but easily reached
I use a black plastic holder with a micro switch with a black toggle boot over it (helps to make it not visable)
I attach the holder to the steering column bracket on the left side
then run a wire with a spade connector to the other side of the fuse socket.
On models with the glass fuses I break a fuse and split into two remove any glass left and trim the fuse link and solder the each wire separately to each fuse end and use them instead of the spade connectors to attach to the fuse panel
With the switch in the off possition there is no power going to the fan and when you need the fan just turn the switch on.
With the switch off...This will aslo help with reducing heat coming in to the car
Hope this helps
John
[QUOTE=csradley]It shows Hi/Med/Low and off.
[/QUOTE]
mkapp7879 2008-10-17 17:29:59
[/QUOTE]
Is the 'off' WITH the low/med/high on the fan switch or is it with the top slider for the AC-heat control?
My books show the 77 heater controls the same as my 78-79 control.
As stated in the 78 owners manual
'Notice: Whenever the ignition switch is turned ON, the blower motor will automatically operate at LO, MED, or HI depending on switch setting. There is no OFF position"
Does it look like this?
Thanks for the reply back guys. As I remember it the fan control switch has OFF/Low/Med and Hi, so it look like the picture except mine has off as well. I'll verify again in the morning. I can slide the slider to the off position as well and it still blows on low with the fan switch on off and slider on off. Another thing that seems odd is if I but the slider to max the fan blows on hi speed with no control via the blower/fan switch.
The vette has A/C but it it not fully installed currently, compressor and lines are not on it as I just did a engine swap and plan on converting the system over at some point.
My 77 vette is an early year model with alarm switch in the fender if that makes any difference.
Thanks...
While working on it today, I removed the blower fan switch and it still stays on low. I verified the wiring was good and correct. Next checked the blower resistor and it's good and I checked the relay and it seems to be working as it should. But just in case I am going to replace it tomorrow as it's a cheap part at the local parts house.
The only thing that I have found that makes it not run on low when the switch is off is to remove the brown wire from the blower resistor,all other fan fuction still works just not the fan running on low when switch is off.
I'll work on it again tomorrow... But from the post from others it is possible that it is suppose to be that way but then again why would the switch have an off setting?
in Forum: C3 Electrical
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