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Switched and Ignition Switched Live Question

Tiger Super Six - 17/7/11 at 10:03 PM

I am about to wire in my ECU (Omex) and it has a thick wire that it says should go to a switched live and a thin wire that should go to an ignition switched live. The second one I get, but what's the difference for the switched live? Should that just go to the battery and if so, why is it called a switched live?

Mark

jabs - 18/7/11 at 06:22 AM

As it is a thick wire then assume it will take some current so rather then go directly via ignition switch it will go via a relay switched by the ignition

[Edited on 18/7/11 by jabs]

John Bonnett - 18/7/11 at 06:33 AM

quote:
Originally posted by Tiger Super Six
I am about to wire in my ECU (Omex) and it has a thick wire that it says should go to a switched live and a thin wire that should go to an ignition switched live. The second one I get, but what's the difference for the switched live? Should that just go to the battery and if so, why is it called a switched live?

Mark

I'd recommend a call to Omex for clarification. It's not something you'd want to get wrong.

Tiger Super Six - 18/7/11 at 10:07 AM

Cheers for the replies chaps.

I have phoned Omex support and they have said that the thin wire runs the ECU and draws 0.5 amp so that's fine for them to quote as going through the ignition switch.

On the other thick wire, this is the feed for the coil pack which draws larger current so they can't state on their paperwork that it can go through the ignition switch as some ignition switches will not take it. He asked where I was taking the ignition switch from and I said the old ignition switch live wire that went to the + side of the pinto coil. He said as it used to run the coil it should be fine to wire up to this switched live.

Bascially, he said the usual way to wire it up is to join the wires together and run them through an ignition switched live, but they can't put that down due to some ignition switches not being up to the job.

Mark.

snowy2 - 19/7/11 at 07:20 AM

switched live......a live that is "live " after it has been switched....i.e. by an ignition switch or relay or any other switch.

First wire would be supplied by a relay which is operated by the ignition switch , the second will be direct from the ignition switch.

Why? modern switches are not normally capable of switching large current flows so relays are required.....

nick205 - 19/7/11 at 08:55 AM

I'd wire it via a fused relay to avoid any uncertainty with the ignition switch. It should also allow you more freedom in positioning the components for the shortest wire lengths and a good feed to the coil pack. It will also make for easier changes in the future should you want to change any of the components involved.