VEMS EGT/WB gauge powering

[Bram]

I am busy to connect the VEMS EGT/WB gauge to the electrical system. I am not sure what would be the best way to link it up to the electrical system, as there are a few requirements:

1. needs to be powered directly after the engine has been started
2. consumes 3A at start to warm up the WB lambda

This is the device I am talking about:

http://www.vems.hu/wiki/index.php?page=AfreshTiny

Does somebody have a tip where to connect it to? The gauge will be fitted inside the ash tray btw, so if I can get some power from that area it would make things a bit easier. Would the sigarette lighter be an option?

[audiman]

any ign+ live feed will be fine. go into the wiring from the ign. switch and find a live with ign on AND with engine running.

Its a great gauge, i have one in the golf. Not cheap, but good quality products are usual expensive.

[Bram]

ok, thanks. Good idea. Will the DIN at the radio work too?

[ranz]

ok, thanks. Good idea. Will the DIN at the radio work too?

Yes, that will work to. Do not forget connect the - to the engine, not to the body.

[Bram]

Yes, that will work to. Do not forget connect the - to the engine, not to the body.

The - from the gauge you mean?

[ranz]

Yes, the negative (blue wire) has to be connected to the engine, and as said, the red wire connects anywhere where is +12V when engine is running (I have connected it directly to wire what comes from the ingnition switch (but I can not remember the color of the wire rigt now).

[Jamo]

Yes, that will work to. Do not forget connect the - to the engine, not to the body.

Err why? http://www.phattransmissions.com/VEM...de/README.html

Connect the red power wires to a suitable +12v supply and the blue ground wire to a clean grounding point.

The cleanest ground point is a separate wire to the body you'll get no interference that way or rely on the stock wiring.

[Bram]

Good point. I also did not see the engine as good grounding point of a standalone gauge inside the cabin. I will connect it to the body/chassis somewhere.

[Bram]

I got the tip from Jyrki to use a relays with integrated fuse holder to switch +12v and the Gauge on and off. I think that is a safe way to do it. I will connect the relais to the ignition wire +15V or radio wakeup wire (DIN), so it can be switched by turning the key and start the car, and connect the gauge to +12V and the minus on the body. I just need to find a proper +12v wire now.

Cheers Guys.

[GazzaG60]

i kept mine simple. feed from around the wheel ignition live. and ground body.

its not rocket science getting power there.

[Bram]

i kept mine simple. feed from around the wheel ignition live. and ground body.

its not rocket science getting power there.

I know, but I am not familiar too much with car electrics and really want to prevent any fire, short-circuiting, or I don't know what can go wrong here. Better safe then sorry right?

[GazzaG60]

yes too right better safe. i wasn't being funny about it, keeping it simple is usually the best. good grounds are a must. they will throw off egt and afr loads if not good. more than one isn't a bad idea either if the first seems not enough. its not like we are trying to match exactly the NB02 feedback for analysis.

[Bram]

Anyone has a part number for a relay with fuse socket holder?

[ranz]

Err why?

When your ground is from body and somehow your ground cable from body to engine has bad contact (or you forget it connect after disconnecting, my friend forgot that after engine replacment) and you try now start the car, what happens??? by by gauge, that what happens. Starter is trying to get the ground from whatever whats connected to the body ground (lambda sensor body is connected to the engine, cabels from it go to the gauge and gauge is connected to the body).
Thats the reason why most motronic ecu grounds are connected to the engine, not to the body.

[terrybullwon]

Bram is your EGT connected to your gauge or ECU?