Amp draw on tractor?

Dave/MO

Member
What is the amp draw suppose to be with the ignition on. Put amp clamp on positive cable and got nothing. when I pushed start button I got 6.34 to. 6.89. On ignition switch I got .65. Is this normal or is my coil bad? On the wire coming off my alternator I got nothing at all with the ignition on or off. HELP ME!!
 
I'm a little lost here Dave.
I'm assuming you're working on an N of some model that has been
converted to 12 Volt negative ground because you mentioned alternator.
I would expect no current from the alternator unless it were running.
Current on the key switch with key on, engine not running would depend
on the position of the points, opened or closed.
Current draw on the battery cable when you push the starter button would
vary I think, depending on load. Is the starter turning?
What is the problem you are trying to fix?
You may have posted it earlier, and if so I apologize but I don't remember.
 
41 9n 12V. Tractor has not ran for about 2 weeks now. Had gas leaking from carb so I put repair kit in carb. Changed plugs, plug wires, points, condenser and still would not start. Had fuel from bowl to carb and thru carb. took carb off and shot ether up intake and still would not fire. I am think coil is bad because everything else is new.
 
Got it. Sometimes new doesn't always mean good. Specially with today's
parts made to lower standards.
Do you have spark at the plug wires when you roll it over?
If you have a tester, that will work, but if not there should be a snappy
blue/white spark that will jump to a good ground when you hold the wire
close to it. You could also use a spark plug and ground the body of it to
look. Any good plug will work for that.
Use an insulated tool to hold it, or you get to feel that spark!
If no spark, do you have battery voltage to the top of the coil when the
points are open? Does it drop to about half that when the points are closed?
The ammeter would indicate the points opening and closing as well, but I
find it hard to tell when the engine is turned over by a 12 votl battery.
Just turns too fast for the needle to react.
With the front mount distributor you could have a bad coil, or it could just be
a bad connection between the coil and the distributor.
Could also be a bad ignition switch not applying power to the coil.
So rather than throwing money at parts, we need to isolate it to the cause.
 
If I am correct. If I ohm out the ignition switch with it turned off I should get OL on my meter and if I turn key on it should read anything but OL. I will check switch tomorrow and also ohm out coil. When I bought coil it read 3.0 ohms. If it reads lower then it is bad right?
 
Switch should read a dead short, i.e. Zero ohms when on.
The coils seem to be all over the place depending on manufacturer.
If it read 3 ohms when you bought it, it should still read that.
Problem is it can change with heat, so just because it reads 3 ohms
cold doesn't mean it is necessarily "good".
On the other hand, if it reads open, OL, then it is most likely bad.
Wish I could help more with that, but I don't know of any way the average
guy can bench test a coil with any certainty other than checking for an open winding.
 
Check for spark with a plug grounded to the block. Should jump at least 3/16" with a blue white spark. I asked before where you are located in MO.
 
(quoted from post at 00:10:18 05/11/13) I live in Silex. About 10 miles north of Troy
I don't know MO well at all, but if Harold is close to you and willing to help,
I would jump at the chance. He has an impressive collection of vintage Fords.
 
Dave........yer weird squarecan sparkie coil with mandatory "infamous ballast resistor" should pull about 3-amps (points closed); (6-or-12V) with points OPEN you will read NO AMPS. Ittza LAW, Kirchhoff's Law.

Yer 6-volt starter motor will pull about 150-AMPS.

Yer weaksister ignition switch will drop about 1.5-volts when turned on. INFINITY (digital overload) when turned OFF.

BIGGEST problem with 4-nipple dizzy is the points (0.015") Unlike the 5-nipple roundcan coil, the squarecan coil is somewhat "fragile". It overheats and short a few turns and suddenly, NO SPARKIES!!!

Ittza 2-bolt, 15-min job to remove the weird 4-nipple dizzy and change/adjust the points (0.015") on the kitchen table. Just un-snapple yer capple and letter dangle. Installation is a reversal of the removal ...except... finger start the 2-bolts and then install the rotor. Now twist the rotor so the OFFSET tang drive will mate with the OFFSET camshaft slot. Now tighten yer 2-bolts and re-snapple yer capple. Simple, eh?

Remember to "polish" the INVISIBLE corrosion from between the points (0.015") after installation. Me? I clamp a clean $1-bill between the points and pull. Iff'n yer really cheap, tear a strip from HEAVY brown paper grocery sack and use that.

As fer yer alternator, it should be intuitively obvious, yer engine MUST be running. It will put out as many amps as the 12V-battery requires to re-charge and generally that will be about 14.4-14.7 volts across the battery terminals. That is what the BUILT-IN solid state voltage regulator is supposed to do.

CAUTION: digital voltmeters do NOT like N-tractors 'cuz they have SPARKIES running around. Yer readout can be all over the place with the tractor running ........HTH, Dell, yer self-appointed sparkie-meister
 
Never could afford to change parts.On gas leak a bit of dirt can make a carb flood.My tractor floods now and then.It sounds like you are using your ohmmeter on circuits with power in them.That WILL cook your meter.Your new points and condenser may be junk.Old ones good quality.
 
I may have waaaay missed the boat here, but, AMP CLAMP? What is that? I have a couple of what I think of as "amp clamps"... but they are for Alternating Current...like household wiring. I have also had some inductive ammeters, the kind that you slip alongside the wire in question...

An appropriately ranged INDUCTIVE ammeter should tell if you have current flowing through a conductor.... but I've never tried an AMP CLAMP on DC...

Confused..... duey
 

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