Another AAR Valve Question, Where does the red lead go? Options

[Craigers17]

Recently, I've been refurbishing the intake and FI system on the 914. I've noticed that a few of the valves are either inoperable or blocked off or both. The AAR valve red lead was not hooked up to anything. I'm trying to figure out where this lead plugs in? I've attached two pics...one of the valve and one of a a white wire that is pretty much the only thing near the AAR valve. So is this white wire the proper connection for the red AAR lead ? If not, where does the red lead go and what does the white wire connect to ?

I'm going to "PB Blast" this thing as well per some of the other posts, but any help on the connection is appreciated. Thanks!

[BeatNavy]

The AAR lead definitely connects to a white wire. The only other connection like that on the wiring harness goes to the CHT, so if that connection is left over, that's definitely where it goes. Don't short that lead or you'll blow a fuse on the relay board and fuel pump won't run IIRC. In other words, there is a reason that connection is shielded like that.

[Craigers17]

The AAR lead definitely connects to a white wire. The only other connection like that on the wiring harness goes to the CHT, so if that connection is left over, that's definitely where it goes. Don't short that lead or you'll blow a fuse on the relay board and fuel pump won't run IIRC. In other words, there is a reason that connection is shielded like that.

Thanks Rob. You're gonna have to start charging me for technical support! (IMG:style_emoticons/default/beerchug.gif)

The CHT is accounted for and working, so this makes sense. 10-4 on not shorting it, ... while getting this fuel system sorted out, I usually keep the negative battery terminal disconnected anyway. The first time I cranked it after installing the new injectors, I actually had a fire extinguisher right next to the car just in case anything went south!

[BeatNavy]

Thanks Rob. You're gonna have to start charging me for technical support! (IMG:style_emoticons/default/beerchug.gif)

Thank goodness my consulting days are over (I hope). The only thing I still need to know about government consulting is that when the govt customer asks you how much money to implement the recommendations you say "We estimate one million dollars..." and wait to see if they fall out of their chair - if not, you quickly follow up with "...for phase one." (IMG:style_emoticons/default/smile.gif)

I'm sure there's something similar in the Porsche world.

[Craigers17]

So I am still trying to get my AAR valve up and running. I have continuity from the 12 pin on the relay to the business end of the white wire. My volt meter says I am getting around 13.5 volts give or take to my spade connection.

I THINK I had a bad connector on the wire closest to the AAR valve side. After putting on the new connector, that's when I got my 13.5 volt reading. However, I have 2 different AAR valves, and one has been tested good, but neither seem to close.

So, here are my questions:
1. It's possible that I had already warmed my engine up this morning, BEFORE I made the connections functional. So, is the AAR valve ONLY powered during the warm up cycle? In other words, is there a temp shut off, that cuts off after a certain temp?

I can find this out later today or tomorrow morning, when the engine cools back down, but I thought it was worth asking.

2.I am assuming I should have continuity between the red wire connector and the AAR valve canister?

3. The only other thing I can think of is that I need to do more PB blasting on the AAR unit that has been tested, as maybe it locked up again.

Any pointers would be helpful.....I really don't know why I'm "getting worked" by this thing, but I am. Thanks!

[BeatNavy]

So I am still trying to get my AAR valve up and running. I have continuity from the 12 pin on the relay to the business end of the white wire. My volt meter says I am getting around 13.5 volts give or take to my spade connection.

I THINK I had a bad connector on the wire closest to the AAR valve side. After putting on the new connector, that's when I got my 13.5 volt reading. However, I have 2 different AAR valves, and one has been tested good, but neither seem to close. Those AAR leads tend to break off right at the base of the body, which makes repairing them difficult. Even without power to the AAR I believe engine bay temp is enough to make them close eventually, albeit more slowly than it would with voltage across the element. Having said that, yours may still be cruddy to the point where it doesn't want to move either direction.

So, here are my questions:
1. It's possible that I had already warmed my engine up this morning, BEFORE I made the connections functional. So, is the AAR valve ONLY powered during the warm up cycle? In other words, is there a temp shut off, that cuts off after a certain temp? No, my understanding is that the wire has continuous voltage.

I can find this out later today or tomorrow morning, when the engine cools back down, but I thought it was worth asking.

2.I am assuming I should have continuity between the red wire connector and the AAR valve canister? There is continuity, but through the heating element (which will have high resistance). AAR receives 12v from lead and is grounded by bolting it to the mount of the case. You could take a measurement and you should see some continuity I suppose.

3. The only other thing I can think of is that I need to do more PB blasting on the AAR unit that has been tested, as maybe it locked up again. Probably what's going on. You can carefully pry open the top to get better access to the innards for cleaning purposes.

Any pointers would be helpful.....I really don't know why I'm "getting worked" by this thing, but I am. Thanks!

Here is my understanding, inline in Red. Hopefully others can confirm or dispute.

I'd recommend removing the AAR from the car and bench testing it. Wait until it's cold and make sure it's open. Use a jumper to (carefully) connect the lead to the positive battery terminal and use another jumper to connect the AAR body to negative terminal. You should observe it to start closing and be fully closed after 5 minutes or so.

[Craigers17]

Thanks Rob!

Upon reading your response, it just hit me like a ton of bricks what I am doing incorrectly! I'll test it and give feedback....although it might be highly embarassing to me.

[Craigers17]

Thanks Rob!

Upon reading your response, it just hit me like a ton of bricks what I am doing incorrectly! I'll test it and give feedback....although it might be highly embarassing to me.

Resolution: So the "new to me" AAR Valve is now working. The original AAR valve will get warm, but it is not turning. I think with continued PB Blasting, I can get it working as a functional backup.

I forgot to mention in my original post that I had already taken the valve out of the car to test to try to visually watch the internal mechanism "close". My cardinal mistake was , in a moment of immense stupidity, I wasn't grounding the canister to anything after hooking up the power lead.(yes....an epic fail....of wiring 101). So I'm sitting there with the valve in my hand waiting for the internal mechanism to magically close with no ground.....when I read Rob's response to my last post, my mistake became glaringly obvious....live and learn!

[BeatNavy]

(IMG:style_emoticons/default/beerchug.gif)

[dr914@autoatlanta.com]

we are rebuilding them with modern guts now. The aux valve is like a revolving door that opens with heat, either engine heat or its own internal heading element which ever becomes hottest first Hence on a 105 degree day in arizona, the valve is already closed. it becomes clogged from moisture and blow buy which freezes the revolving door most of the time, and other times the heating element fails causing it to close only after a longer period of time. It is on the fuel pump circuit so does not operate unless the fuel pump is running or when the car is running. The fuel pump fuse is the same on for the aux air valve and the heater blower motor. The red wire is connected to the white wire coming off the ignition harness at the distributor. Some have mistaken the connection for the white wire in the earlier harness for the thermo time switch located in the same area