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        General >> Problems >> Electrical wizards needed :)
        
(Message started by: Highlander on May 1^st, 2008, 8:02pm)

Title: Electrical wizards needed :)
Post by Highlander on May 1^st, 2008, 8:02pm

Non starting 24v (Tintins)
Intermittent fault, seems to start if left a while.

PATS light doesnt light at all
Engine doesnt crank
All ignition lights show as normal.
All the usual tests done no joy.
Another ECU tried

Now what I have discovered is...

If the engine loom is disconnected, the big square plug down the offside of the engine then the PATS light shows as normal, no codes and the engine will crank, although obviously wont fire as the wiring is disconnected.

As soon as its reconnected the car is dead again,

I've connected an earth to the engine to rule that out.

So...... next stage i assume is to check all the connections on the multiplug with a meter and find the fault.

Anyone got any theories what it might be before i do the testing?

I cant see any damage as per this http://www.fordscorpio.co.uk/faults_wiring.htm

Title: Re: Electrical wizards needed :)
Post by Matt on May 1^st, 2008, 8:32pm

well first off id say the engine loom is broken, but i couldnt say as to where,

the enging would still crank if the cam or crank sensors were dead, just wouldnt fire, ditto with the injector circuit

could strip the brown plug down and reconenct certain parts, eg injectors

could it be a problem with the start inhibitor on the gearbox? dodgy relay perhaps, the loom does contain some of the boxes wiring . . .

Title: Re: Electrical wizards needed :)
Post by Highlander on May 1^st, 2008, 8:40pm

definitely something in the engine loom which is stopping it cranking.

The inhibitor relay is ok and I assume is wired from the selector multiplug or the gearbox loom anyway.

I might use two old mutiplugs and make an inline tester to see which wire is causing it

Title: Re: Electrical wizards needed :)
Post by Matt on May 1^st, 2008, 8:48pm

theres only so many systems covered by the engine loom,

injectors, cam and crank sensors, coil pack, oil pressure sensor, coolant temp sensors, then the 2 or 3 multi plugs to the box,

the fans, ac, alterator, power steering, coolant level etc are off the front loom with runs fromt each fuse box, down the inner wings and accross the front of the car if i remember correctly,

to me it sounds like a gearbox/start inhibitor problem, just like when you try to start the car in gear, all the systems come on but theres no life in the engine

Title: Re: Electrical wizards needed :)
Post by Highlander on May 1^st, 2008, 9:29pm

Doesnt the gearbox have a seperate loom though Matt?
The box multiplugs run up the top of the box and into their own multiplug beside the engine multplug

I can get the engine to crank no problem but only when the engine loom is disconnected, i was thinking along the lines of the ECU inhibiting it due to a wiring fault??

Title: Re: Electrical wizards needed :)
Post by Tompion on May 1^st, 2008, 9:59pm

I wouldn't have thought a faulty start inhibitor would prevent the pats light coming on.

Title: Re: Electrical wizards needed :)
Post by gozz on May 1^st, 2008, 10:26pm

Highlander.
I have had considerable problems with 12v engine looms whereby even though the part from the offside inner wing multiplug to the engine and box are completely remade,there are still anomalous happenings because the rest of the loom within the engine compartment and about a third of the way across the front of the car,is degraded when cut open.Having said that,the 12v,having a distributor,has three signal wires from the dist module to the PCM bound together inside a shield,and this all degrades causing random signals.Tintin's problem as a 24v may be something similar,or not as the case may be!
GOZZ

Title: Re: Electrical wizards needed :)
Post by Octavian_P on May 2^nd, 2008, 8:21am

If the plug on the TRS isn't seated well it could make the inhibitor not to start the car

Title: Re: Electrical wizards needed :)
Post by Matt on May 2^nd, 2008, 1:19pm

the 2 cossie looms i have both have two connections for the gear box, the go through the vee of the heads then down the back of the engine, then their clipped to the top of the box where they plug into two connections on the same side of the selector, i believe one is the vss cant remeber where the other plugs into

Title: Re: Electrical wizards needed :)
Post by shaun on May 23^rd, 2008, 12:18pm

as matt said the two looms cross over in the middle of the v in a cozzy and the plastic falls off the wires causing all sorts of crap,ive done 3 looms now and thay dont look too bad at first till you have a realy good look with a bright light ,also the wires that come from the box can rub between the bell,housing and the boddy,ive found that too, after all this i hope you have sorted it,if you want any pics to help you let me no n i will email them to you...shaun
;)

Title: Re: Electrical wizards needed :)
Post by shaun on May 26^th, 2008, 7:31pm

i took anouther loom off a car for you m8 tintin is bringing it back with him it neds a small amount of work to it but fingers x :o this should do the job good luck

Title: Re: Electrical wizards needed :)
Post by Highlander on May 26^th, 2008, 8:56pm

Hope so :)