MadaboutKitcars

Now that the engine and ancillaries were fitted it was time for first start of the car.

After replacing the battery (should have thought of that earlier) she kicked into life after a few nudges of the key.SUPERB.

...now the bad news. Took the ign key out and she kept going!!!

I've checked the Ign wiring and this is OK, so I'm guessing something wrong with the 5AS unit wiring or the engine to Marlin Loom in the engine bay.

Before I go ripping the loom to bits does anyone have any suggestions or solved this one previously??


Also....is the height of the collant expansion bottle critical.....can't seem to get mine high enough?



Thanks

Rich

Rich,

PM me you're email address and I'll send u a pic of how I did my expansion bottle as I wanted it as high as possible.

John.

Hi mate.

Sounds like you have connected a perm positive where there should have been a switched positive. At a guess I would say fuel pump relay/mems ignition sense (Green/Pink) as on the digram that should be switched + (Marlin Green). Might be worth checking with a meter at the engine end to see if you get 12V at the green while ignition switch off.

HTH.

Thanks..I'll check it out and let you know what I find.

Also..I've used the Markin 5AS loom but didn't have any instructions on what to wire to what....so I figured it out from the Haynes wiring diag and old plug!

Does anyone have info from Marlin on how this unit should be wired?

Thanks

Rich

I have this from the Marlin wiring instructions:

MARLIN 5AS WIRING HARNESS
white/orange to E.C.U pin no 13
Going by the diagram, this should be Blue/Slate.
black to earth
white to switched live [EXI green]
blue to permanent live [EXI purple]
white/brown to dash board light [EXI pink/blue]

Hope that helps.

...Ahhhhhhhhhh!!...2hrs later, and still struggling with the wiring.

On further analysis the situation is this:-

When I connect the battery first time the immobiliser will arm and disarm OK with the fob. Lights work with no ignition so perm positive OK on this circuit.I've also double checked the 5AS wiring and this matches OK with everyones diagrams and my own logic.

I've metered the switch +ve(green) at the ign and the engine end and this is zero volts with the ign off...(As is the green/pink mems ign sense/fuel pump relay).....ok so far.

I have nothing connected to position 1 on the ign (aux)...so when I turn key to pos 2 the fuel pump primes, injectors chatter a bit etc and the 3 red warning lights illuminate on the dash (charge, oil and brakes) ready to start the car. At this stage the wipers and windscreen washer will work if required..so again these circuits OK.

Problem is then when I turn the key back to off (without starting the engine) the 3 warning lights stay lit on the dash and the green (switch +ve) stays at +12 volts. Only way I can then get everything back to normal is to disconnect the battery and start again.....it's as if the switch +ve is being 'latched' live by one of the relays?

Same happens if I start the engine...only when I remove the key the engine keeps running!

I've tried disconnecting the MEMS relay unit and going through the above procedure. This helps in that the ign lights will extinguish when the key is turned back to off....but obviously no start!...

Is it possible that the MEMS relay unit is knackered?..or is there something obvious I'm missing....

All help greatly appreciated...

thanks

Rich

Hi rich.

i had some funnies when I wired the greens to the ign switch wrong. Would turn over but not fire. Would only fire when turned to ignition and started using a screw drive on the starter.

Wire colours on mine might be different to yours butshould be able to work the out with the lables on the back oy your switch to compare.
http://www.johnil.pwp.blueyonder.co.uk/5exi/ign%20switch.doc


Sounds a bit unusual why at the off position, there's switched 12V just when you turn the key to ign but not when you first connect the battery.

I had a funny with the instruments whee the ABS light would not go off (Had to take the bulb out in the end to solve it). Try turning on the ignition without the dials connected and see if the switched 12V disappears.

The fuel pump relay is the only one out of the four that is switched.
This is how mine is wired.
http://www.johnil.pwp.blueyonder.co.uk/5exi/engine%20wiring.jpg

Next step would be to unplug the relay pack and check the voltages again.

HTH

Hooray!!!!!!! Wiring problem solved

Thanks for all the help (limpabit esp.)....followed all the checks suggested and came up with nothing unusual.....so went through what wires were conencted to the switch +ve at engine end again (Marlin Green).....it was then that I realised the Brown and Pink (N/K) that was surplus from the charcoal cannister purge valve would have been better insulated off instead of being connected to green +ve....don't I feel like a muppet!

Anyway...car behaves exactly as required now and I can turn off the ignition with the key!

Just need to raise the coolant exp. tank now......

...on with the build...

Rich

Glad you got it going Rich. it's a great feeling isn't it.

Still don't explain though why when you switched of the ignition, the fuel pump replay still got supplied 12V and kept the engine running.

....weird I agree.

Only reason I can think is that when the pink/brown was energised whilst connected to the green then this latched a relay in the MEMS that didn't unlatch when ign turned off...possible??

Rich

Ahh I think the reason is the Green wire you had connected to the N/K was getting a perm + from the main relay keeping closed. But because of this, green is now effectivly perm +. That would mean MEMs was earthing this relay to activate it because it senses + on the G/K. Good to know the reason behind it!