Wiring Omex Relays

[Chris_Mi 6]

Right, where to start

 

I am starting to install an OMEX 600 (and Jenveys) in my Miami. I have present the OMEX pre made up loom and labels, and all seems to be good, apart from me not understanding the relay operation

 

I have installed the wiring exactly the same as the car it was taken out of. The only thing is that the car I took it from had a push button start - you turned the ignition to switch 2, then pressed the button, and it fired up (Fuel pumped primed on 1st ignition switch). Unfortunately during taking the wiring apart, the 'push button' circuit became detatched and I don't know where it was from/attached to with any certainty. In the Miami, I want the car to operate normally on the ignition (i.e. without the push button), so I want to get rid of it. The engine won't be in for a couple of months, but I really need certainty that how it is currently wired will work first time.

 

Can anyone please please therefore confirm that the the wiring diagram below (how it is wired in to the Miami)

1) is correct

2) and that the 'cut' wires off the brown multiplug and strange relay are not needed

3) whether a 1A fuse is required on the live to the OMEX (because this was not present before), and where it should go

 

Your help is really really appreciated!

OMEX Relay Wiring.doc

Edited October 2, 2011 by Chris_Mi

[Chris_Mi 6]

ok then, no takers ???

 

Can anyone tell me whether this old thing is a relay, and where the thick brown wire 1R(?) and the white wire 76 eventually lead to? Due to the size of the brown, I am guessing it is direct 12V from battery +ive?

 

Are the green, light blue and earth wires from terminals 4, 1 and 3 respectively needed?

[Miles 331 1 Cars]

No idea without spending some time, But the std wiring loom should not be used at all and those links are asking for allot of trouble, Looks like Pug Performance work or that's how there GTi6 conversions are done.

 

The relays from the ECU are all 0v switched and not 12v like most people would wire up a relay

 

I'd just bit the bullet and buy a new loom from them and start again

[Chris_Mi 6]

The thing is, the loom is in great nick. It is clearly one of the preassembled looms that you can buy direct from Omex (with the correct relays). However, for the life of me, I cannot find an Omex wiring diagram, and the one they supply is complete cack!

 

I'm sure this is not as complex as it looks I just need some pointers to get me on my way!

 

Should say also - its an alloy 16v Mi16

 

Thanks

Chris

Edited October 4, 2011 by Chris_Mi

[Chris_Mi 6]

Right fellow enthusiasts! Since members are more keen discussing whether or not it is inconsiderate or morally right/wrong to distress passengers by driving briskly rather than helping me out , I have done some deep Google digging.

 

Basically, it looks like I am repeating what Sarty and many others have done (in a similar way) when wiring in Megasquirts etc. However, my issue/s is/are not entirely the same.

 

I think I am getting there, and have now revised my diagram to get rid of the 'strange' relay (left in my last diagram) that didn't seem to be doing much.

 

I have read that the OMEX 600 needs a 12V permanent feed and a switched live feed (presumably from ignition). What I didn't notice is that the OMEX premade harness has 'thin' red wires (approx 1.5mm), and 'thick' red wires (approx 2mm) - the difference is subtle, although I now think that all the thin reds are for a switched live (some fed through the ECU), and all the thick reds are permanent live (from battery +ive)

 

Please can someone confirm?

 

My new diagram does not have any control on the starter. I thought pins 6 & 7 on the 7 pin brown multiplug (thin yellow and thick red) had some feed to the starter, but these do not seem to be connected to anything.

 

Please can someone confirm what/how the starter motor is fed? Will it be from outside of the ECU loom? Are the thin yellow and thick red pins 6 & 7 needed?

 

The VERY high level OMEX wiring diagram (bl**dy useless if you ask me) shows that a 1Amp fuse is needed on the live feed to the ECU.

 

Does anyone know whether this would be the permanent 12v feed (i.e. between pins 87 and ECU on the right relay in my new diagram), or would this be needed on the switched live (i.e. between pin 86 and the ECU on the right relay in my new diagram). Is a 1Amp fuse required on both of these feeds?

 

Any help is really really appreciated

OMEX Relay Wiring.doc

[dcc 855]

one thing i will say from personal experience. strip the entire loom out of the car and use a wiring guide, label all the wire, and start from there!

[Miles 331 1 Cars]

It's quite hard to say with the pic above, the switched positives all come from the battery/igintion switch and not the ECU, this keeps the current away from the ECU and my comment that the relays are 0v switched.

The starter again is just the ignition switch, wire 46 in the car.

 

As DCC's said, it's quicker to start fresh allot of the time as it can take hours to figure out what others have done, plus with a link like that in the Tacco relay plug it looks very poor and un-reliable, Not been crimped properly or even the right colour crimp

Edited October 6, 2011 by Miles

[Chris_Mi 6]

the switched positives all come from the battery/igintion switch and not the ECU, this keeps the current away from the ECU and my comment that the relays are 0v switched.

 

I think the ECU is wired in this way now.

However, the relay on the right is a premade OMEX relay that comes readily wired (as shown in pic below). The only thing that I do not understand with this is that it feeds the high current circuit back to the ECU through either of pin 87s. This doesn't seem correct to me, however this is how it comes from OMEX, so it must be correct. Can anyone confirm?

 

The starter again is just the ignition switch, wire 46 in the car.

 

I was under the impression (from both Grimbadger's multiplug thread, and several comments that I had seen) that either pin 6 or 7 of the 7 pin brown multiplug were something to do with the feed for the starter. Is it definately the case that the starter cranks from wire 46? This is present and fine, whilst pins 6 and 7 of the multiplug were removed at some point.

 

As DCC's said, it's quicker to start fresh allot of the time as it can take hours to figure out what others have done, plus with a link like that in the Tacco relay plug it looks very poor and un-reliable, Not been crimped properly or even the right colour crimp

 

I am starting afresh Before I can correct any mistakes thought, I need to understand the circuit fully, and as you can tell, wiring is not my forte!

By the way, I have now removed that relay plug, because it doesn't seem to be adding much i.e. in my revised diagram the left relay acts as the tacco relay.

 

I think I am getting somewhere.....slowly.....

[maxi 36 1 Cars]

Im not quite sure what you are trying to attempt above but......

 

The omex loom is a stand alone management loom. As with any of these, give them a live, switched live, earth and use their relay to drive the fuel pump and the car will run. It really is very simple wiring.

 

Your starter motor is fed a permanant live from the battery via the main positive lead which also connects to the shunt box (power distribution box in the engine bay) and on to the alternator. The trigger wire from the ignition runs in the sensor loom (brown multiplugs under the dash) and has nothing whatsoever to do with the omex management loom. I think you need to get your head around the fact there are two looms to the engine, management (omex) and the sensors ( starter trigger, alternator trigger, coolant temp gauge, oil temp and oil pressure gauges, low oil pressure warning light, oil temp, overheating light). Hope this helps.

 

Maxi