im back with another issuise ..grrr

Not getting too far found that relay r9 isnt clicking when igitions turned on .yet bloody things showing power .if i hold relay in all lights appear on dash yet still wont start .looks like a auto election .tryed another relay with no luck

but didnt you say that you tryed other good fusebox instead? cos if you did it's something else

adaptorman said:

Not getting too far found that relay r9 isnt clicking when igitions turned on .yet bloody things showing power .if i hold relay in all lights appear on dash yet still wont start .looks like a auto election .tryed another relay with no luck

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It sounds like its the power feed to the operating terminal of the relay and all other systems depending on the same feed. When you say it shows power on the relay that will be the live for the load of the relay not the switched operating coil that you can see.

Have you tried changing the relay for a good one? Does the old relay work off the car if you hot wire it to a battery? Try the simple things first especially if as you say all the lights come on when you manually operate the thing.

found a issiuse , ill try explain relay location (r9) black relay , I noticed first click of the key I heard a click the second ignition turno very faint click (sometimes wouldn't evern make a noise , I removed the relay tested the pins which show as they should apart from one pin only showing 10v ,instead of the 11v (yet opsite pin wasn't dropping to 0 volts when ecu came live, (maybe battery was a little low) , I basicly pressed contact inside the relay to find all the remaing lights powered up ie glow plug,engine management light,and diagnostic port connects, I cleared all the faults,went threw checking injector injection , crank sensor and rpm all, along with other assorted sensors all powered and showing correctly , yet when I cranked engine all I can fain black smoke but wouldn't evern try to fire ,,tried a spot of carb cleaner nothing , im personaly thinking this guy hasn't hasn't tested ecu correctly . so ill presonaly sent it off just for piece of mind tbh ,,, will keep you posted ,,, ill get there ,, (one day)

yes cos the main relay is commanded by the ECM on it's coil but it reverts the feed to the ECM through the contact

the main relay's coil feed from ECU is on the same black plug pin 21, which pin is in line between pins 5, 6 and 30 ...so all the trouble is on that area, or internal ECM crack there or a wiring issue between the ECM and fusebox

@adaptorman ...with ECM plugs connected insert a sewing needle into the wire from pin 21 of black plug, put ignition on and measure ... you must get EARTH with ignition on, if you have unplug the inertia switch and bridge pins in the plug, make sure that the feed from fuse F13 in engine bay gets to the brown/black wire at the inertia switch then through it back to the fusebox...cos the +12V from inertia switch and the earth from ECM are energising the coil of the main relay...also check for earth on all the black wires to ECM black plug...this one make it unplugged to not get something backwards

see attachment, follow the path of the coil's circuit and you'll understand...come back with the finding and we'll get to a conclusion

and any measurements you want to make with plugged ECM or otrher ECUs that's the way: thin sewing needle through the insulation to reach the 'core' then measure on it...good luck

right im roughly with u ,sure the wife will have one somewere ,,, saved diagram ill report which wire,pins doing what , little cold now and chuffing snowing to top things off

take your time... we are close to an answer just let's hope you didnt let too long that bypassed relay to backfeed the ECM which didnt give the earth path for a reason...if ithe relay doesnt get earth path from the ECM the cause must be found cos that ECM depends on other inputs too...so even if you thought you elliminated the issue by pressing manually the relay it's not so

im totally with you on that ,,, brilliant ,,,only issiuses i didn't understand if everything was working while cranking on the engine wouldn't evern try to fire/start when cranking while the relay was manualy pressed , ie there was diesel smoke but no fireing , unless ecm is faulty ,, will update tomorrow ,,

I'm following your posts closely hoping it throws up something that will help me.

On the 110 defender where is the Main relay & fuel relay.
I thought the main relay was behind the dash and fuel under seat.
But it looks like main is under seat and fuel is at the fuses in front of gearstick.

So whats the difference between ECU & ECM are they not the same unit?

Ruari said:

I'm following your posts closely hoping it throws up something that will help me.

On the 110 defender where is the Main relay & fuel relay.
I thought the main relay was behind the dash and fuel under seat.
But it looks like main is under seat and fuel is at the fuses in front of gearstick.

So whats the difference between ECU & ECM are they not the same unit?

Click to expand...

I dont know much about Defender, here is about a D2, which as engine management is quite close as they could share the same engine ECU =ECM = engine controll module.. but the power distribution is different ...if you watch that part of diagram i posted you'll see that's how the "ECU" is officially named: ECM....

ECU=electronic controll unit, and there are more ECU's on a D2, even the fender has an ABS ECU so by naming it ECM there's no confusion that's if we want to be 100% accurate, otherwise simply ECU=ECM

Right pal f13 has 12v .but pin21 off black plug shows a thin blue red strip .when switched igition on not showing earth just shows a single bleed .removed r9 engine relay pin1 not showing 12v

did you get to the end of it?

Never found the problem .so i replaced the ecu lom which cured the problem .i assumed a brokern wire or wires in loom .tbh .fingers crossed its great .only small thing ive notice smell of strobg feuling from exhust on idiol (maybe because old cat convertor was removed .) Starts runs well ..fingers crossed ...

i had similar problems with mine . i rang emmotts of colne explained the fuel pump +heater coil have a delayed acion before coming on from 30 sec to 1 day or 2 they said it is possible the engine ecu so i bit the bullit drove 207 miles there they fitted another ecu. the car has been running 3 days now no problems yet