Rear ventilation from two to multiple speed - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kikkegek · 11-17-2010, 08:22 AM

hello,

the switch for the rear ventilation in my ride is broken. I need to replace it. I checked to see if the wires are still working. and they are. I measure an amperage of 1A at LO and 10A at HI setting.

But LO is too low and HI is too high. HI feels like a storm inside the car. I am now looking for a solution or new switch to make it possible to select speeds in between or at least a middle speed, so I can vent the rear of the car "normally".

any ideas?

and where can I find the controller for these two speeds right now?

motornut · 11-17-2010, 08:35 AM

the switch in the dash?
the speed/voltage/amps is not controlled by the switch
it's just a switch

kikkegek · 11-17-2010, 09:01 AM

Quote:

Originally Posted by motornut

the switch in the dash?
the speed/voltage/amps is not controlled by the switch
it's just a switch

huh? so the fan in the back has a connection for LO and for HI speed?

In the LMC catalog a resistor is shown in the wiring.

but I have no clue (yet) on where this is inside the car?
and I dont know the specs of this resistor?

The way LO speed is made is either by deviding the current (voltage) in two using a resistor in parallel to the fan or by putting it in series with the fan, thereby deviding the available amperage (power?) in two...I am not sure about the last thing though.

can you help me with that?

motornut · 11-17-2010, 10:15 AM

yup hi and low
can't find a decent pic of the switch....on work puter
if i was home.......crap the burb an't there either lol
i tore it all out and my wires outa the 88 as the heater hoses started to leak
ac quit
wires coiled on the hump.......
the black had one switch/window/gate
one for fan
gold one had one for speed

motornut · 11-17-2010, 10:25 AM

but it's just a switch
i used mine for the dome light
up turns the light on
middle off but dial still works
down works with the doors

kikkegek · 11-17-2010, 10:43 AM

he thanks motornut (you gotta real name?)!

Here is what mine looked like before I took the bottom one out:

The top one has electrical and vacuum hose connections on the back, but does not seem to do a thing. I need to look into this.

The bottom one says REAR A/C and has LO (left) OFF (middle) and HI (right).
It has a 3 wire connection to the back of it and no vacuum connections.

Is yours identical?

babyJay · 11-17-2010, 11:55 AM

As stated before, the switch is just a switch, it is merely opening or closing a current path. Is this an "aftermarket" add on or do all Subs have this. Maybe you can PM a mod and have this moved to the Sub-thread for Suburbans?

48cj2a · 11-17-2010, 01:32 PM

I had to replace a blower resistor assembly in my 03 Burban because it was only working on the two highest settings and not on low and mid.

Wonder if you could adapt one of these and a modern switch from a donor?

Do a google search for suburban heater blower a/c control module

motornut · 11-17-2010, 03:55 PM

hi its John
looks the same as yours

11-17-2010, 08:22 AM	#1
kikkegek Registered User Join Date: Aug 2010 Location: Netherlands, The Hague Posts: 1,518	Rear ventilation from two to multiple speed hello, the switch for the rear ventilation in my ride is broken. I need to replace it. I checked to see if the wires are still working. and they are. I measure an amperage of 1A at LO and 10A at HI setting. But LO is too low and HI is too high. HI feels like a storm inside the car. I am now looking for a solution or new switch to make it possible to select speeds in between or at least a middle speed, so I can vent the rear of the car "normally". any ideas? and where can I find the controller for these two speeds right now? __________________ My dreamride / project:1977 GMC C15 Suburban In storage: Monster - 1974 GMC Suburban 25hundred Sold : Chevrolet Suburban K20 Silverado 1986 Guide: real HID projectors for 4x6 headlights link: DIY LED TAILLIGHTS

11-17-2010, 08:35 AM	#2
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Rear ventilation from two to multiple speed the switch in the dash? the speed/voltage/amps is not controlled by the switch it's just a switch __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350 Last edited by motornut; 11-17-2010 at 08:36 AM.

11-17-2010, 10:15 AM	#4
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Rear ventilation from two to multiple speed yup hi and low can't find a decent pic of the switch....on work puter if i was home.......crap the burb an't there either lol i tore it all out and my wires outa the 88 as the heater hoses started to leak ac quit wires coiled on the hump....... the black had one switch/window/gate one for fan gold one had one for speed Attached Images __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350 Last edited by motornut; 11-17-2010 at 10:26 AM.

11-17-2010, 10:25 AM	#5
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Rear ventilation from two to multiple speed but it's just a switch i used mine for the dome light up turns the light on middle off but dial still works down works with the doors __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350

11-17-2010, 10:43 AM	#6
kikkegek Registered User Join Date: Aug 2010 Location: Netherlands, The Hague Posts: 1,518	Re: Rear ventilation from two to multiple speed he thanks motornut (you gotta real name?)! Here is what mine looked like before I took the bottom one out: The top one has electrical and vacuum hose connections on the back, but does not seem to do a thing. I need to look into this. The bottom one says REAR A/C and has LO (left) OFF (middle) and HI (right). It has a 3 wire connection to the back of it and no vacuum connections. Is yours identical? __________________ My dreamride / project:1977 GMC C15 Suburban In storage: Monster - 1974 GMC Suburban 25hundred Sold : Chevrolet Suburban K20 Silverado 1986 Guide: real HID projectors for 4x6 headlights link: DIY LED TAILLIGHTS

11-17-2010, 11:55 AM	#7
babyJay Arrived on a Pale Horse Join Date: Mar 2007 Location: SnagTown Indiana Posts: 2,524	Re: Rear ventilation from two to multiple speed As stated before, the switch is just a switch, it is merely opening or closing a current path. Is this an "aftermarket" add on or do all Subs have this. Maybe you can PM a mod and have this moved to the Sub-thread for Suburbans? __________________ Jason 87 V30 350TBI/400 White w/Boss V-plow 89 R3500 CC SRW

11-17-2010, 01:32 PM	#8
48cj2a Registered User Join Date: Feb 2010 Location: Central, IL Posts: 599	Re: Rear ventilation from two to multiple speed I had to replace a blower resistor assembly in my 03 Burban because it was only working on the two highest settings and not on low and mid. Wonder if you could adapt one of these and a modern switch from a donor? Do a google search for suburban heater blower a/c control module __________________ 03 Suburban Z71 Z71 98 GMC Yukon SLT 4x4 Yukon 86 M1009 CUCV Project Milverado 48 Willys CJ2A 48CJ2A

11-17-2010, 03:55 PM	#9
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Rear ventilation from two to multiple speed hi its John looks the same as yours Attached Images __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350 Last edited by motornut; 11-17-2010 at 03:57 PM. Reason: haha forgot my name

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