Guys just trying to setup the "failsafe" part of my AEM gauges. I have taken a photo of the instructions that came with the gauge, see below. This is on a "normal closed) relay. The low side (ground output from the Widebands Failsafe can be used to turn ON a NC (normally closed) relay and interrupt the output signal from a boost controller to its boost solenoid (shown below.) NOTE be sure that pulling power from the boost controller will decrease boost down to the waste gate spring pressure rather than increase boost to the turbochargers max.This will depend on what type of waste gate is used and how it is plumbed with the vacuum hose.

 

I then cam across the following diagram below,

The diagram again is to cut boost to standard waste gate pressure, however this diagram is different and has the 12v supply going into pin 85 rather than pin 86. The diagrams seem to say the opposite to each other, and now has confused me. Any input or questions welcome.

That's a touch odd. I thought I had my head round that till you pointed out they contradict each other. It's a nice feature what ever, just like the stock safety boost system but more robust.

That's a touch odd. I thought I had my head round that till you pointed out they contradict each other. It's a nice feature what ever, just like the stock safety boost system but more robust.

 

Is the second diagram the same "NC" diagram?

doesn't matter on pin 85 0r 86..... they are a coil that moves the connection from between pins 87a (NC connection = normally connected to pin 30 unless a 12v and earth are connected to pins 85 and 86)

Then the connection is broken and pin 30 is connected to pin 87....

If using these diagrams please use a fuse on the 12v feed and also an unused crimp connector pushed onto the unused pin 87 to insulate it, as it could touch an earthing point and blow the output of you boost controller......

Only difference in diagrams is 12v feed.... first is from same point as boost controller and second is just any ignition feed.......

 

Hope this makes sense..... it did in my head anyway...... lol

 

Edited May 10, 201510 yr by veilside01702

Pins 85 & 86 are the connections to the relay coil, it wouldn't matter if the connections were reversed, the relay is switched via the coil.

Pin 30 is the common or supply connection.

Pins 87a & 87 are the output connections.

When voltage flows through the coil, the coil is energised & switches the relay from Pin 87a to Pin 87.

Thanks for your answers guys, that make it much clearer. I can move forward with this :thumbup1: