Doug's A/C System, R&D/Build Thread Options

[ChrisFoley]

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Sorry I can't answer your question Fred. It looks good to me but I don't know sh!t about AC control circuits.

[Chris914n6]

You left out the binary pressure switch. Also you want the comp to cycle on and off separate from the fans. Shouldn't be too hard to find a diagram from one of the hotrod sites. AC wiring is basic but not THAT basic.

[ClayPerrine]

Alright. My 914 is operational! Turning my attention to finally wiring up all my A/C components. Got to get the A/C cooling before the Texas heat set in down here. I've created a very ugly wiring diagram. Anybody see anything incorrect here? I can run the evap from either the #8 or #9 fuse (switched power) or directly from the battery. I ran a separate 10 gauge wire from the battery to the frunk for the condenser fan. Just need to connect all the wires to the components and the relay. Thanks all.

From experience, you probably need two relays, one for the compressor, and one for the fans. If you are running fuel injection, you want to add an idle up device too. Get a tank switching valve for a Ford pickup with dual tanks. Cap the normally open side, and plumb it in parallel with the decel valve. Hook the wire up to another relay. Then once you have the car started and the AC running, you will have to add restrictions to the intake hose of the valve to lower the idle speed. I used a dowel rod the same size as the ID of the hose, and drilled out the center until I got the same idle speed as when the AC was off.

Hope that helps.

Clay

[Rider914]

From experience, you probably need two relays, one for the compressor, and one for the fans. If you are running fuel injection, you want to add an idle up device too. Get a tank switching valve for a Ford pickup with dual tanks. Cap the normally open side, and plumb it in parallel with the decel valve. Hook the wire up to another relay. Then once you have the car started and the AC running, you will have to add restrictions to the intake hose of the valve to lower the idle speed. I used a dowel rod the same size as the ID of the hose, and drilled out the center until I got the same idle speed as when the AC was off.

Hope that helps.

Clay
[/quote]

This is genius!

[friethmiller]

Thanks All! Really appreciate the input. Sorry if I oversimplified the wiring. The instructions (image below) that I received in Custom Auto Air's 914 A/C kit was beyond terrible. While their phone support is good, they don't really know the 914 setup. From what I can gather, this kit was "acquired" when they merged with another company several years back. I'm just trying to figure it out the best I can. I'll see about adding a relay for the compressor. I'm running dual carbs, BTW.

[friethmiller]

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Sorry I can't answer your question Fred. It looks good to me but I don't know sh!t about AC control circuits.

No worries, Chris. You've done plenty already to help my 914! Which, by the way, sounds so sweet with your custom exhaust/muffler. Get a ton of compliments on the sound of my engine. (IMG:style_emoticons/default/first.gif)

[friethmiller]

After fixing a leak, and securing a new ground for the evaporator unit, my A/C is finally operational!! I still need to tighten the compressor belt a bit more but she's blowing colld air. Not a moment too soon! It's officially summer here in TX. Shout out to Doug (the OP) and several of the others that have chimed in on this thread. Thanks y'all!!

Here's a pic of the wiring in the frunk with the condenser & dryer



With everything buttoned up:



Pic of the flexible condenser intake flap (part of a door seal from Home Depot):



Pic of compressor with hoses - Note the 2 new 10 gauge wires on the battery for the evap and condenser.

[ChrisFoley]

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[worn]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

[friethmiller]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

[Front yard mechanic]

I really like the looks of your ac setup maybe try to fit a fast idle solenoid

[friethmiller]

thanks! Funny, I was just searching for an idle solenoid for Weber 44s. Might have to use something like this. I was also wondering if Tangerine Racing’s manual idle control might work as well.

[ChrisFoley]

thanks! Funny, I was just searching for an idle solenoid for Weber 44s. Might have to use something like this. I was also wondering if Tangerine Racing’s manual idle control might work as well.

It would probably be useful for that. Although the solenoid applies pressure close to the point of need. The hand throttle applies tension to the throttle cable.

[friethmiller]

thanks! Funny, I was just searching for an idle solenoid for Weber 44s. Might have to use something like this. I was also wondering if Tangerine Racing’s manual idle control might work as well.

It would probably be useful for that. Although the solenoid applies pressure close to the point of need. The hand throttle applies tension to the throttle cable.

Thanks for the info Chris. Not sure of the lead-time on this but I just ordered your hand throttle kit. I want to be able to control idle myself.

[Chris914n6]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

It's called a choke. There even was an electric version in the 80s lol.

[friethmiller]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

It's called a choke. There even was an electric version in the 80s lol.

I don't think I have chokes on my 44 IDF carbs. Haven't been able to find any, manual or electric.

[ClayPerrine]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

It's called a choke. There even was an electric version in the 80s lol.

I don't think I have chokes on my 44 IDF carbs. Haven't been able to find any, manual or electric.

Under that cover are two pistons that can be raised up to make the mixture richer for cold running. You need the covers that have the arm and cable mount to make them work. That works fine for cold running but not for idling up for AC compressor load.



You can buy them here: https://www.dellorto.co.uk/shop/weber-carbu...ting-mechanism/



A kicker solenoid like the one shown previously would work. I have never done one, as I don't like carbs. But you would have to fabricate a bracket to hold it in the right location to open both carbs.

Clay

[friethmiller]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

It's called a choke. There even was an electric version in the 80s lol.

I don't think I have chokes on my 44 IDF carbs. Haven't been able to find any, manual or electric.

Under that cover are two pistons that can be raised up to make the mixture richer for cold running. You need the covers that have the arm and cable mount to make them work. That works fine for cold running but not for idling up for AC compressor load.

You can buy them here: https://www.dellorto.co.uk/shop/weber-carbu...ting-mechanism/



A kicker solenoid like the one shown previously would work. I have never done one, as I don't like carbs. But you would have to fabricate a bracket to hold it in the right location to open both carbs.

Clay

Clay, thanks for the info! I hear ya on the carbs (IMG:style_emoticons/default/smile.gif) As you know, chokes aren't exactly necessary items down here in Texas. I'll look into the solenoid option. Pulling the acceleration cable slightly or something on the master carb (manual or automatic) is all I need. I'm running Tangerine's pulley system.

[ClayPerrine]

Congratulations! Did you understand what Clay was saying about a two tank Ford? He is one of the most expert hot weather guys I can think of, but what tanks? Am I too far north?

I understand and believe you but I don’t have fuel injection. Is there a different solution for carbs? The compressor pulls my idle down a little too low.

It's called a choke. There even was an electric version in the 80s lol.

I don't think I have chokes on my 44 IDF carbs. Haven't been able to find any, manual or electric.

Under that cover are two pistons that can be raised up to make the mixture richer for cold running. You need the covers that have the arm and cable mount to make them work. That works fine for cold running but not for idling up for AC compressor load.

You can buy them here: https://www.dellorto.co.uk/shop/weber-carbu...ting-mechanism/



A kicker solenoid like the one shown previously would work. I have never done one, as I don't like carbs. But you would have to fabricate a bracket to hold it in the right location to open both carbs.

Clay

Clay, thanks for the info! I hear ya on the carbs (IMG:style_emoticons/default/smile.gif) As you know, chokes aren't exactly necessary items down here in Texas. I'll look into the solenoid option. Pulling the acceleration cable slightly or something on the master carb (manual or automatic) is all I need. I'm running Tangerine's pulley system.

If I were doing it, I would put it in the tunnel next to the bell crank on the pedal box. Make it push on the linkage like the hand throttle does.

Clay

[friethmiller]

If I were doing it, I would put it in the tunnel next to the bell crank on the pedal box. Make it push on the linkage like the hand throttle does.

Clay

Oh! I like that idea too! Thanks.