Calling All Electrical Gurus,

[Guest mcramsay]

As ive said time and time again im using a modular loom on my kit, i know some people think this is a waste of time but ive found the loom pretty straight forward to fit so far. however i have now run into small problem and just wanted to ask some advice, hopefully its a pretty straight forward. either i am at fault or the loom is at fault!

 

basically the loom has 2 fusebox's one for the headlights and etc, and one for the ECU, the ECU box running things like the injector feeds, fuel pump rad fan and a switched live. sadly there is not a "drawing" per say with the loom, only a table of what wire does what, this is the page details that will help show my problem:

 

 

hopefully you can make the above photo out well enough to read .

 

my problem lies with the Blue Cable on the ECU connector. as you can see on the table it is described as the " switched live from the main relay" i originally had this cable wired up to the main 12V supplies to turn on the Emerald ECU. however when connecting the loom up to the battery (All earths and etc connected as they should be) the ecu would not turn on .

 

this prompted me to look deeper into what this Blue cable actually does, tracing it back it comes from PIN 86 on the Main relay. and looking at all other relays pin 86 is normally connected either directly to earth or via a switch to earth (like the column switches or an ecu switched earth) so on Pin 85 of the relay there is a switched 12+ and pin 86 is claiming to be a switched 12+ from the main relay...which cant make sence as the relay i believe should earth through Pin 86.

 

i rewired the ECU plug so that the Emerald was taking its supply from the Green wire on the ECU plug on the loom, this is just a bog standard switched 12+ from the fusebox, meaning the blue wire was not connected to anything, when powering up the loom again nothing happened. When i applied an Earth to the Blue wire on the ECU plug on the loom, (so in effect presenting an earth to PIN 86 on the Main Relay, the ECU and fuel pumps switched on as i expected.

 

what i dont understand is why would the BLUE wire on the ECU connector plug be there? as there nothing that would switch to earth on the ECU that would switch the relay.

 

all i can think is that there is a mistake with the loom, and this blue wire should connect directly to earth. that or i am completely looking at the wrong thing!

i have contacted the bloke who made the loom, who has been great at providing advice on the loom, who has said he will carry out a test and get back to me, just wondered if any of you guys could offer any explanation ......

[Pete Mar]

Hi

 

I know on on my Omex I had the same problem. If this is the same then the blue wire is not a supply from the main relay but a way for the ECU to switching the relay. As you say pin 86 is an earth pin in the control side of the relay, my Omex ECU controls each part on the system by switching the earth side of the circuit.

 

I like you have the ECU powered off a green switch live.

 

Hope that helps.

 

Pete

[Pete Mar]

I take it you have also purchase a Rapid fit loom like me?

[Guest mcramsay]

Yes I'm using the rapid fit loom, did you use the green switched live on the ecu plug to power the ecu and then connect the blue wire directly to earth then?

[Guest mcramsay]

As I do not believe the emerald has any way of controlling the earth side of that relay

[Pete Mar]

Yes that was the direction I went in as I had a chat with the guys at Omex and they really could not see why you need to have the ECU control that relay. Just make sure that the wire on the live side of the control side of the relay is switched, I can't remember if my one was or I had to connect it to a green switch live that is controlled by the ignition switch.

 

Pete

[Pete Mar]

Omex told me I could use one of the aux out puts if I really wanted to have the ECU do this so I guess yours might well have the same aux out put options.

 

[speedtripledan]

just a side question it says rapid fit how rapid is it and how much do they cost?

[Guest mcramsay]

there are diffrerent looms to suit different cars, also there is a basic modular loom, with out without ECU and a modular loom with sierra switchgear again with or Without the ECU fusebox.

 

i went for the sierra switchgear modular loom with ECU. which was £275 with £15 PP.

 

i cant rate the loom highly enough, and it pretty much fits the Zero perfectly. really really easy to work out whats what on the loom as well. aside from this issue (which is now sovled) it took me 30 mins to connect the loom up to the sierra switch gear. with the supplied plugs, and it looks 10000 times neater than my first attempt with the old Zero loom.

 

i know from previous posts that you are not a fan of the modular looms, but honestly i can say that the fitting of this loom has been easy peasy. and is 100 times neater than it would have been had i made the loom my self. all the hard stuff is done for you.

[Pete Mar]

I have to agree. My loom was easy to understand, fitted really well and is about half the price of the GBS. If your using the GBS plenum I used a Ford engine loom to connect things like the injectors, TP sensor and the air control valve, needed a little work and cost me £15 on ebay but is very tidy looking job.

[speedtripledan]

was just curious really. your right i dont like them i was wondering how cost effective there were including time of install