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1944 ford cmp laa tractor broken down :-(


POPPY

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According to the quoted RAC stats the second commonest cause of breakdowns both pre and immediately post war was halfshafts (followed by cylinders/pistons then clutch and only after that lot fuel issues)

 

The order was the same immediately post war, although the incidence of cylinder/piston issues had risen by a couple of percentage points. The story in 1950 was pretty similar, which surprised me a bit!

 

Now I would be wary of transposing these findings to a modern context, but I suppose the lesson is that checking the ignition first is a good plan. My own experience with a number of vehicles now is that is even more so as pattern components of indifferent quality are readily available on t'internet. I have seen new but duff spark plugs, coils dying after only a few hundred miles and rotor arms by the bucketload (well thats a bit of an exaggeration but you know what I mean..). I can never remember having to change a rotor arm in the 1970s, but have changed rather a lot in the last 12 months.

 

So there we go....

 

I will get that troubleshoting guide scanned.

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I had a coil fail on my WOT2 a couple of years ago. It was working fine one day and then, on the day of it's MoT, it wouldn't start in the MoT centre's car park. After getting home via the AA, I replaced the 12v coil with a new one from the Green Spark Plug co and it's been no problem ever since.

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Good evening all, i am back from my third night of working on my broken down Ford CMP and the story gets worse:cry:.

I managed to pick up a new top of the range 6V ignition coil from Rex Ward (who is currently on holiday in sunny Barnstaple and had one with him:):):)) and fitted it in no time but there is still no power to the distributor?

 

The kind chap i purchased the Ford from informed me that the Ford is running on a 6V system (Thats why i purchased a 6V Coil).

 

But it turns out the Ford vehicle battery is a 12v batt, the starter motor is a 6 volt type, the front head lamp bulb is 6 volts, and the rear indicator bulbs are 12 volts???

I really dont know if i am to fault find and repair her as a 6 volt or a 12 volt system? If it is a 12 volt system then i have now probably fried the 6v Coil that i drove all the way to devon today to collect.:blush:

 

The Farmer has been good as gold letting me keep my Ford in his drive way(after breaking down 3 x nights ago) but i a keen to sort the electrics out and get a spark going to the distributor so i can get her under hard cover:) I am sooooooo confused . com:embarrassed:

 

Mark

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Good evening all, i am back from my third night of working on my broken down Ford CMP and the story gets worse:cry:.

I managed to pick up a new top of the range 6V ignition coil from Rex Ward (who is currently on holiday in sunny Barnstaple and had one with him:):):)) and fitted it in no time but there is still no power to the distributor?

 

The kind chap i purchased the Ford from informed me that the Ford is running on a 6V system (Thats why i purchased a 6V Coil).

 

But it turns out the Ford vehicle battery is a 12v batt, the starter motor is a 6 volt type, the front head lamp bulb is 6 volts, and the rear indicator bulbs are 12 volts???

 

I really dont know if i am to fault find and repair her as a 6 volt or a 12 volt system? If it is a 12 volt system then i have now probably fried the 6v Coil that i drove all the way to devon today to collect.:blush:

 

The Farmer has been good as gold letting me keep my Ford in his drive way(after breaking down 3 x nights ago) but i a keen to sort the electrics out and get a spark going to the distributor so i can get her under hard cover:) I am sooooooo confused . com:embarrassed:

 

Mark

 

Mark, you're confused, so am I from what you have just said. The old coil would no doubt have had some marking on it to denote its voltage. Not sure of the history of this vehicle without going back through the threads, but maybe someone "converted" it to 12volt, but had not changed the 6volt headlamps as they did not consider using them, hence why the indicators are 12volt.

 

I doubt there is a voltage dropper in the system, but just in case there is, why not use a multimeter to check the voltage going to the coil. If 12v, then the answer is to try a 12v coil, but make sure it is a full 12v one and not one intended for ballast resisted systems as in a lot of modern vehicles.

 

regards, Richard

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As Richard says, if it is a 12v battery it will be a 12v coil for sure. Ignore the starter motor - most 12v conversions use the same 6v starter as it will cope well with the higher voltage. It may be that someone has wired the two 6v headlamps up in series instead of changing to 12v sealed units or whatever the CMP uses for candles. The 12v indicators are a positive sign that it is now a 12v system.

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Ok , just to get you home, get a long wire from your battery .....

 

You know, that looked just like it was going to read.......all the way home to a mains battery booster, and crank it home on the starter.

Certainly not with a 6v starter! :nono: :D

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As mentioned most people keep the 6v starter as they run fine on 12v, why not just get a multimeter and check the voltage at the battery even if you have run it down you will know whether it's a 12 or 6v job. Six volts fully charged usually around 7.5v max. Twelve volts fully charged 13.5 ish. If you find out what battery you have use the right coil and as suggested as a get you home trick wire a live wire direct from the battery to your coil. If you still can't get a spark then it is a question of starting at the beginning and working your way through ALL the ignition system mate. If I lived nearby I would love to give you a hand maybe if you contact your local MVT group someone there would be willing to help you ? It could be something simple like a broken wire it certainly sounds as if electrics were not the previous owners specialist subject ! Best Wishes and Good Luck, Dave

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The low tension side of the coil is wired to the coil resistor and circuit breaker board (mounted behind the dash - this thing http://www.vanpeltsales.com/FH_web/FH_images/Igntion-Partspics/11A-12250breaker-resistor.jpg). I wonder if the 12V has blown something on there.

 

If so then bypassing the board and supplying -ve volts to the low tension side of the coil would get you going. You can get a spare from Van Pelt http://www.vanpeltsales.com/FH_web/igntn-partsprices-pg2.htm

 

The connection goes from the coil to the resistor (looks like this - http://www.vanpeltsales.com/FH_web/FH_images/Igntion-Partspics/18-12250R-resistor.jpg ) to the ignition switch, so you could just bypass the resistor if that's what's gone.

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This might help. See wires 16 and 24.

 

I notice that wire 16 runs through one of the junction strips on its way between the resistor and the ignition switch, so it maybe worth checking that the screws are tight (if they are still used).

 

CMP wiring.jpg

Edited by Lauren Child
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Mark,

 

Sorry to hear of your problems.

I suspect the 6V/12V issue may be something of a red herring here, bearing in mind that the vehicle was running ok to start with. In your position, I would put the original coil back on and go back to basics.

First of all, you say there is no output from the coil, how have you established this?

Start by checking that petrol is getting through to the carburettor (loosen union on carb, and crank engine over a couple of times - there should be a good flow), if not, locate and rectify problem. Also check that there isn't water in the petrol, or any other contaminant. Check also that the air filter isn't blocked.

If the fuel side of things is ok, start on the ignition. First, remove one spark plug and earth it to the engine block whilst cranking the engine over. Is there a spark across the gap? if there is, the problem is not with the ignition. If no spark, make sure that the plug leads are all numbered, so that you know which cylinder they go back to! Remove distributor cap, and check that the carbon plunger is present and free to move. Check for signs of tracking or cracks - if present replace the cap with a new one. Remove each lead in turn (one at a time, so they go back in the same place) and check that all connections are sound, and that the leads themselves are ok. Pay particular attention to the king lead from the coil to the distributor, again replace any which are suspect. If all is ok, turn your attention to the distributor itself. Is the rotor arm present and intact? Clean points, and re-set gap. Crank the engine over and check for a spark at the points as they open - you should be able to see and hear this. If there is no spark, then either the condenser has failed, or there is a fault in the low tension circuit. This could be as simple as a failed fuse (check with a meter, don't rely on a visual inspection), or could be a broken or loose wire - you will need to use your meter, set for continuity test, to work your way through the circuit to see where the fault is. Don't forget the earth strap from the engine to the chassis, if this has worked loose or failed, then that is the cause of your problem.

Hopefully, this should enable you to locate and rectify the problem. Incidentally, the easiest way to tell what voltage the vehicle is running on is to look at the battery. A 6V battery has three cells, and three filler caps. A 12V battery has 6 cells and 6 filler caps. A modern battery should also have a label showing voltage and amp/hours.

Best of luck getting it sorted, and don't get too downhearted - my Bedford QL broke down before I even got it off the drive, when it was delivered. At the time I thought I had made the biggest mistake of my life, but now I wouldn't sell it for the world!

Cheers, Mike.

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This might help. See wires 16 and 24.

 

I notice that wire 16 runs through one of the junction strips on its way between the resistor and the ignition switch, so it maybe worth checking that the screws are tight (if they are still used).

 

[ATTACH=CONFIG]81046[/ATTACH]

 

Thats most kind ! Thank you :)

 

Mark

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