GTD airconditioner

On the ac unit supplied by GTD, what does the pressure safety switch control, the fan or the compressor ? What about the thermostat with the capilary tube,what does it control? How are these wired to the main dash control? Any help would be appreciated.
 
BC
The LP/HP switch (safety switch)controls the compressor clutch power either directly or by relay.The thermostat also controls the compressor clutch.
Usally power is supplied to the evapourator unit (under dsah) through the thermostat control out to the LP/HP switch than to the compressor clutch via a relay.
hope this helps.
Clayton
 
What about the fan does it get wired into the same series with the thermostat and safety switch or is that too much of a load?
If it does, this means the fan would be on whenever the compressor is on.There is another safty switch available that has three functions (low pressure 30lbs,high pressure 380lbs,and fan on at 220lbs).What switch would be better?
Thank you
 
I don't know the specifics of the gtd wiring but i'll try to make it simple. You must use relays, one to the compressor and on to the fan(s). Use the wire between compressor relay and compressor to power to trigger side of the fan relay. If the condensor fan is the same as your cooling fan(s) you must use a diode on this wire and splice in after the temp switch for cooling fans. As for the switch the simple hi/lo is the easiest.
Hook this and your climate temp sensor to control the trigger side of the compressor clutch relay.
So much for making it simple..... one more snag. Hook it up so the ac switch is powered by the blower for your heater.
Now if your as confused as i have made myself, tell me what your car has for ac/heater components (Blower with different speeds or single, ac switch, separate fans or condensor/cooling combo, one or two of them )and I can draw up a wiring diagram, MIGHT be easier.
 
G

Guest

Guest
The switch you describe, BC, is called a trinary switch. This is the one you want. When wired into the ground side of the fan relay trigger, it will turn on fans when the pressure gets to the preset and cuts off the compressor if it gets too high or low. I have four ways my fans trigger: trinary switch on A/C, adjustable thermostat with sensor on metal tubing just infront of the radiator, a temp switch in the intake manifold as a backup and a manual override toggle on the panel. The only diode I needed was on the indicator light that tells me if the fans are on. If any of these switches are closed it grounds the relay trigger circuit (+ side is always hot) and turns on the fans and turns on the indicator lamp.
 
I have two powered control knobs.One is the blower for a/c and heat(off,low medium,high).The other knob is for a/c only and controls the temperature.It consists of a thermostat with a capilary tube.The tube is mounted inside the evaporator touching the coils.When the thermostat gets too cold for the desired setting it shuts off the compressor.To use the heat you turn the thermostat to it's warmest setting,which turns off the compressor,then you open a cable operated water valve.I plan on mounting the condensor and fan in the engine bay.I don't have enough room to mount it in front of the radiator.How often does your fan turn on when you have the a/c on ? Since the engine bay isn't the optimal cooling place for the condensor,I don't know if I should have the fan come on whenever the compressor is on or have a trinary switch control the fan.
Thanks for the help.
 
There really is no single right way. I work on Honda's mostly and the fans come on instantly, if i remember right, with the trinary switch it is delayed for a few seconds and runs on after(I know my brothers 89 firebird was like this) most window mounted ac units for houses trigger both at the same time. point being, if you have one switch already, use it, it will work and both are just as easy to wire, especially with the condensor fan being separate. If you have a strong enough relay (40 amp ??) you should be able to run the fan and the clutch on the 1 relay. Just make sure to use a heavy guage wire on the source and accesory side of the relay, 14 awg should be more that enough. Lastly, just make sure the condensor can get fresh air, it should work fine.
 
Hi guys, BC, the trinary should swithc the fans on as soon as AC is selected. The thermister probe should not touch the evap coil, just be about 5mm away. when you turn the stat dial to AC off then yes you open water valve for heater. If you had the Condensor rad infront or behind the water rad then you must get fans on when AC is on. use the Trinary to do this. Do you have the old style small rad version? has it got a built in fan? You could upgrade to a infront of water rad type that will be more efficient. Anyone knows that to put the AC condensor in the back with the exhaust next to it is no good. you will be in a constantly humid car. Why GTD did it that way is beyond me. I always mount mine in front of the rad with fans drawing fresh air through for max efficiency. Hope this helps.

All the best

Mark
MDA
 
I have an upgraded large aluminum radiator with two large fans so this doesn't give me enough room to mount the condensor in front of the radiator without refabricating the whole thing.I could possibly mount the condensor behind the radiator,but how efficient would that be ?
 

Howard Jones

Supporter
I don't know where you live but if you plan to drive you car in the summer, 80-90 degree days do everything you can to mount a proper condencer in front of the radiator. Leave the GTD condencer on the bench, makes a good paper weight. Vintage Air makes a condencer that fits perfect on my GTD. I think it is 23" long and almost the same height as the radiator. Do not mount behind the radiator. If you put it there it will not work at all. This is for sure!

[ February 16, 2003: Message edited by: Howard Jones ]
 
BC

I also use a Vintage Ac condenser (18 X 14). I took the fan off of the GTD condenser and made a shroud for the new condenser.

I plan to use the condenser in the rear (passenger side). If you need photos, e-mail me.
 
Hi Guys,

Have been reading this with interest as I have a GTD with the A/C package from GTD and have been disappointed with the output.

The condenser is mounted in the rear, just inside the rear deck, in front of the rear wheel. Whilst the unit does work, seems to only just be able to hold the temp down (it didn't in the queue to get into Le Mans!). The other problem I think I have is the evaporator seams to freeze up and the air flow stops. Has anyone else had this problem (if so how did you get around it)?

Faili F, could you also please send me the pics of your setup.

Thanks
 
David, a freezinng evaporator is usuually a sign of a bad "ETR" switch.
There should be one of these with a probe that senses the temp of the evap core,,,,, when the core gets too cold, it will cut off the compressor.
 
Hi David,

I sent you photos of the condenser. Let me know If you need more shots.

Good luck
smile.gif
 
Reviving this old thread.
Planning to install an airco unit and wondering how to guide the hoses to the condensor.
Orginally on the GTD, the condensor is mounted in the rear (which I prefer in terms of length and keep it small) but it is not working due to the heat of the engine.
advised is to place the condensor before the radiator but how to route the hoses with a GTD ?
Has anyone pictures of how he did the routing of the hoses ?
 
Hi Brett,
I am following your build thread aswell.
Do you have pictures from the front and rear side front to see how the tubes run outside. Does your front nose still fit since there is not much room between the nose and the chassis.

Geert-Jan,
Is yours not cold enough ?
Is it the orginal GTD setup or different ?
Why not passing by with the GTD and have a nice cold Belgian beer at my place.:drunk:


Regards
Andy
 
It gives a cold breeze, but not like you are used to in modern cars.
I don't use it a lot, but when I do I am it's just a bit more convenient inside the car.
I had some (minor) issues with it, that made me thinking of getting rid of it.
But for the last couple of years it's been trouble free, so now I'm not sure....

My wheel has been damaged (long story) and is being repaired. As soon as it's back, I'll let you know. That beer sounds tempting.... (My favorite is Duvel, especially the tripel hop!)
 
Back
Top