Sonic wiring

[skyrangerman]

Hi all sonic builders.
Just about to tackle the wiring of my sonic, not overly confident about it.
I have the mev loom of wires and there two small electronic boards linked by some wires. Looks like one of the boards has some relays and fuses. Does this mean that I just need some fuses and relays for the engine side, how many other relays and fuses would i need , and I take it they would be around the engine bay area. Any help on what is required on top of what mev has supplied would be a great help.
thanks in advance
Jonathan.

[andybaird]

Hi Jonathan

I was nervy at doing the wiring on my Sonic at the start to.

If you look at my build thread you can see the two boxes that I put the fuses & relays in. One under the dash with the control panel for the dash and one in the engine bay with the fuse box and four relays for the starter, fan, main, and fuel relays.

If you just do one wire at a time.

Hope this helps

Cheers
Andy

[skyrangerman]

Hi Andy,
Thanks for your reply, so would i be right in saying that what you have in those two boxes is all that is needed in the way of fuses and relays?
Also what size relays have you used for the engine ancilleries in your white box.
Many thanks for your help.
Jonathan.

[avantkiwi]

I ended up add 3 boxes in total, but I did not use the MEV dash. 1 in the engine bay, 1 in the front and 1 in the foot well. I needed the extra box to house the indicator and hazard relays.
Exactly the same as Andy, 1 wire at a time, tag it, solder it and cover it.

[skyrangerman]

Cheers for that, can you remember what amperage relays you used on fuel pump, starter , cooling fan and main.
Thanks Jonathan.

[andybaird]

Hi Jonathan

I think it was 30 Amp relays that I got from e-bay
Also you need a fuse box that holds 4 fuses. I got one that holds six so I could add accessories.
They are on the white box with the diagnostic plug.
The black has only got the control panel from the Mev dash.


Cheers
Andy

[skyrangerman]

Thanks for the help Andy and Avantkiwi, just got in from the garage and am starting to feel a little bit better about it all, disecting the donor loom and working out what bits I need, it is starting to make a little sense now,have mounted two boxes, one on the steering column and one in the engine bay and have mounted the ecu. Found it a bit of a job to work out which end of the mev loom was the front and which the back, seems to have nearly the same color wires out of each end, think I have got it the right way round now. Dont think it will be long before I am asking some more questions. Your help is much appreciated. Jonathan.

[veefour]

Hi Jonathan do not get overly worried with the wiring I found all

the supplied instructions well laid out and easy to understand.

I have now wired 2 rockets and 2 sonics and the best way is to

lay all the loom out on the frame where you would like it to end

up, apply loose cable ties at various corners of the frame so you

can thread additional wires around where you need them.

Stick religously to the correct colours and add all the wires you

need as said one at a time and have them ending where you

want boxes e.t.c and add your tag.

Leave a little bit of length on your wires it is alot easier to

shorten than extend.

As said 4 30 amp relays don't use cheap ones and use relay

bases not loose terminals.

I boxed the MEV circuitry at the front and the additional relays in

the engine bay with the diagnostic socket and a 6 way fusebox.

Don't remove the unwanted wiring from the Ford loom until your

car is running and all electrics tested.

Then pick and cut out the unwanted wires, neaten up and tape

and/or trunk .

Keep it all tidy as you do it at all times.

It is 100 times easier to wire a car if you wire tidy.

[skyrangerman]

Many thanks for the info Veefour, In my quest to keep it tidy and neat, is it ok to cut and rejoin(solder and heatshrink) wires from the engine loom to the ecu so as to shorten and get rid of some of the un necessary length other wise i will have to double them back on themselves lots of extra wire, by this i mean some wires which are connected correctly but go all over the place instead of nice correct routing.
Many Thanks
Jonathan.

[veefour]

Yes Jonathan it will make the engine loom far tidier with a thinner

more flexible loom.

Nice to hear you will be jointing the cables properly with solder

and heatshrink.I have seen so many car resto's and kit car's

ruined with blue crimp-ons and scotch-locks everywhere.

[veefour]

PM sent Jonathan.

[avantkiwi]

Definitly only use crimpons as a temp measure. Solder and heatshrink every connection if possible. It is not only tidier, but far more secure and less likely to leave you chasing a dodgy connection at a time in the future.

[skyrangerman]

Hi all,
Could anyone tell me, on the Mev relay/fuseboard, the M6 bolt connection in the middle that is said on the instruction sheet to be + POS BATTERY, does this mean direct from the battery(live all the time) or via the ignition switch(only live when ignition turned on)?
Thanks Jonathan.

[andybaird]

Hi Jonathan

If I remember I think I fitted it to the battery. My dash is live all the time. The Side lights don't need the ignition on & there is a light on the dash that is always flashing when the battery is connected.
I will have a look to check if I get a chance tomorrow.

Andy

[veefour]

Live all the time off battery positive terminal. Also protect the

lead with a fuse to be safe but rate it high.

The biggest rating in a standard blade fuse is 40amp which even

with everything on will not draw 40amp but should the lead ever

short on anything for any reason it will blow instead of burn.