# Management problems! VU4 and switchspeed



## vr_ben (Aug 5, 2010)

Hi,

I installed bags about a month ago on my mk3, with the accuair vu4 manifold and switchspeed management. It has all been good until recently, I have no idea whats wrong with it now. The car has electrical issues, the fuel pump doesnt turn off when I take out the key and so I have to disconnect the battery every time its parked in an attempt to have some battery left for when I next want to start it up. For the last couple of weeks the switchspeed controller has been flashing red and not turning on the compressors, I figure this means low power? That hasnt been a great problem, I would just unplug the controller and the compressors would fire up and fill the tank and it would be ok. Not sure why it would think its not getting enough power, the ground and everything should be fine.

Now however, when I plug the battery back in (before I even put the key in) the controller starts flashing randomly and the compressors and vu4 start doing random things. If i turn the ignition on the compressors kick on and it seems the vu4 opens and shuts random solenoids in one crazy hectic kind of dance, and doesnt take any notice of what you do to the control.

Ive been through all of the wiring and it looks ok, I pulled it out and redid everything just to be sure anyway, it works some times, and sometimes it still does the same thing. I wired up my own little ghetto control with a few switches which just put battery power to the corresponding solenoid in the vu4 thinking that this would still work when the rest doesnt. When the switchspeed controller and all of that works, it works a treat, but when the switchspeed stuff is having a spaz, pushing the switches does nothing, even if the vu4 isnt plugged into the switchspeed ECU. This has me pretty stumped.

Any ideas? Im well and truly confused and frankly, am pretty ****ing sick of this car.


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## son of planrforrobert (Dec 21, 2009)

Your problem may be simpler than you think. The moment you said that your fuel pump stays on when you turn the key off immediately makes me think your ignition switch is going bad...and it will make your car's electrical do crazy things. I had 4 go bad on my mk3 in a matter of a year or so, and when they went bad, a few different things would happen:

- the door chime would never turn off
- the radio would turn off then turn right back on and stay on
- my head/tail lights would not work properly

It's not outside the realm of possibility for your issues to be centered around a bad ignition switch (and because of that, a dead or dying battery). My advice is to buy an OEM switch at the dealer (the aftermarket pieces are crap) and get a new battery in there and see if that solves it.


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## vr_ben (Aug 5, 2010)

Thanks for that, I actually already do have a new ignition switch coming as I figured thats likely what was casuing the fuel pump problems, and had considered it could be somewhat responsible for the suspension aswell. Guess ill have to wait for that to come and see if it fixes things. Have a lot of driving im meant to be doing this weekend and thre switch wont be here in time, so guess ill just have to see how it goes.


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## vr_ben (Aug 5, 2010)

Swapped the ignition switch today, made absolutely no difference. The switchspeed seems to be dead now. I think maybe the switchspeed ECU is fried? I got the switches I wired up working again, so just need to figure out how to wire up the compressors to work and it will be fine to drive. Does anyone know if I can wire that pressure sensor which is connected to the ecu just to the relays? It has three wires coming off of it so im not sure.


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## mikesvw2.0 (Aug 27, 2009)

When the switchspeed controller starts flashing it could be a number of things depending on how many times it flashes. The owners manual gives a list of things to check relating to how many times the controller flashes.


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## Sobayb6 (Sep 10, 2011)

There seems to be quite a few threads on switchspeed lately acting up including mine, has me a little worried about the reliability of it and maybe considering going with the vu4 to an avs controller.


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## blue bags (Jul 1, 2009)

Ive seen very similar symptoms with switchspeed before with power issues. when the ECU is only getting partial power from the battery itll blink red, and its normal for things to get a little wacky if power is cutting in and out. If you put a new battery in your car i bet it would be fine, until your other electrical problems kill it again. basically, if possible, try and fix your battery draw problem and chance are itll be good assuming your wiring is correct


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## son of planrforrobert (Dec 21, 2009)

/\/\/\ I was just going to suggest this. If your ignition switch has been going bad for a while, it will slowly kill the battery (ask me how I know  ), especially if your battery was already a couple years old.


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## vr_ben (Aug 5, 2010)

Yeah thats what im thinking. Ive checked the voltage at the harnesd and it seems to be okay, but I think that it mustn't be consistent. 

Wish I had the money to get a new battery and to get a pro to look for the problem. I can build an engine and most mechanical things, but little electrical things like this are what drive me crazy.

Sent from my HTC Wildfire using Tapatalk


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## son of planrforrobert (Dec 21, 2009)

Easy way to test your battery:

1. Walk out to your car and pop the hood. Measure voltage across the battery terminals.

2. Turn car on, and let it idle. Measure voltage across the terminals.

3. Turn car off, wait 5 minutes, measure voltage across the terminals.

If #1 is anything less than 12v, your battery is toast. If #2 doesn't produce something like 13.5ish volts, your battery is toast (and your alternator may be wearing out...but that's unlikely).

If #2 is good, but #3 drops back to less than 12v, your battery for sure is garbage.


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## vr_ben (Aug 5, 2010)

Thanks, ill give it a try later, although I think it will be okay, I do check the voltage on the battery and it seemed to be alright. However, when I unplug my battery when im parked and then plug it back in when I try to start it, it sometimes has gone flat, so i think theres probably something wrong with it. the battery is only about 2 years old, but has been completely drained more then a few times which wouldnt have been good for it. 

Id love to get a new optima battery, relocate it to the boot and run all new power cables and ground cables to everything to be certain that all of those are fine. 

Sent from my HTC Wildfire using Tapatalk


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## [email protected] (Feb 10, 2012)

Hey Ben, 

The best route on checking what's causing the draw is to go fuse for fuse with the key off. Pull a fuse and stick your meter in the terminals for the fuse. Doing this you can see what kind of current draw each fuse is seeing. There shouldn't be anything drawing over .3 amps. If you find something with a heavy draw that's more than likely the issue. 

If your battery has correct voltage (over 12 volts) and the SwitchSpeed is still acting strange, than something may have been damaged during the whole battery/voltage issue. If so, than give me a call so we can swap some parts quickly and get you back on the road.

Jesse


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