Headlights kill engine

JRinElginTX · Apr 13, 2014

Odd thing happened today, while running the tractor out in the field, I turned on the headlights and it promptly killed the engine. This happened 3 times in a row. I just completely rewired it and all worked well for around a month. This is a 12 volt system with a 1 year old battery on a 1948 8n. When I try and turn the lights on now, they don't burn. However have good juice to the starter. One other point of interest, if I leave the battery connected for longer than 2 days, it kills the battery. So now I just unplug the positive terminal when not in use. I didn't replace any of the other electrical components during the rewiring/restoration process. My thoughts are a lose wire, but not sure. Everything seems secured well in the conduit. Thanks again!

russb wa · Apr 13, 2014

Electricity works a lot like water in plumbing. I like using a probe which is similar in shape to a screwdriver with a wire through the handle and a light inside the handle. instead of a blade it has a point which you can use to puncture the insulation on a wire, making electrical contact and see what's hot or not.

Hope you like puzzles and I hope this helps.

JMOR · Apr 13, 2014

(quoted from post at 23:20:18 04/13/14) Odd thing happened today, while running the tractor out in the field, I turned on the headlights and it promptly killed the engine. This happened 3 times in a row. I just completely rewired it and all worked well for around a month. This is a 12 volt system with a 1 year old battery on a 1948 8n. When I try and turn the lights on now, they don't burn. However have good juice to the starter. One other point of interest, if I leave the battery connected for longer than 2 days, it kills the battery. So now I just unplug the positive terminal when not in use. I didn't replace any of the other electrical components during the rewiring/restoration process. My thoughts are a lose wire, but not sure. Everything seems secured well in the conduit. Thanks again!

ince it is no longer "as it left the factory", we have zero idea of what components you have and how you wired them. Some will make guesses, even with zero knowledge of what & how you have converted it. If you can fill in the blanks, I can without a doubt help you.

Mr. T. Minnesota · Apr 14, 2014

JR,
Check the voltage of your battery when charging? Sounds like you are possibly drawing down on an already close to dead battery! If that is not the case, sounds like you have rewired something wrong. Just a thought!!
Mr. T. Minnesota

2nforever · Apr 14, 2014

I have experienced the same thing on my 2n and it turned out to be a frayed power wire to the Solenoid. It might also be the wire being to small to carry the current for both then engine and lights. I have to double my wires here for the lights to work properly.

souNdguy · Apr 14, 2014

how do you have the lights wired?

thru the key switch?

if so.. may be insuficient switch or wireing, assuming you don't have any switched direct shorts.

also. what conversion for 12v? 3 wire alt?

are you leaving the excite tab powered full time?

JRinElginTX · Apr 14, 2014

I used this diagram that I found on-line.

http://www.myfordtractors.com/12volt.shtml

It's a one wire alternator, it has a new key switch, and new light switch as well. Not too sure what the excite tab is, but I'm "excited" to find out!

The wires are all new and I stepped up the gage on the wire size than what the original specs called for.

The voltage looks fine when it's on the charger, however I might try slow charging it at 2 amps on a trickle.

The alternator is a one wire Delco and I used the free diagram off of the internet. I'm using the same junction block and two resistors.

I did purchase a multimeter, so if all else fails I can run with that. Any cautionary tales on using one of these? Haven't done that before.

Hope that I answered all of the questions and again thanks so much!

souNdguy · Apr 15, 2014

I don't prefer the 1 wire jobs. if I were you i would see if it could be run as 3 wire.

wire from key on to #1 tab thru a 194 lamp, #2 tab to charge stud. these tabs may live under a black plug..e tc.

what coil. oem 6v square?

JRinElginTX · Apr 15, 2014

Here's a picture of the alternator before I restored it. Where are the other tabs? What is the excite tab? Also the key switch is a 2 post.

JMOR · Apr 15, 2014

(quoted from post at 00:18:55 04/16/14) Here's a picture of the alternator before I restored it. Where are the other tabs? What is the excite tab? Also the key switch is a 2 post.

hat is wrong. Certainly not like the link you referenced earlier. Are you sure it is even a one-wire alternator?

Jimps · Apr 16, 2014

Like JMOR said, that is wrong. Here is a pic of how it should look at the alternator:

My yellow wire goes from Tab #1 (Excite) back to ignition switch. Tab #2 (Sense) is pig-tailed back to Bat post on Alternator (smaller red wire).

Hope this helps.

Jimps in GA.

8N Ren · Apr 16, 2014

JR, do yourself a favor and replace that rubber gas line with a steel one, you don't want to catch fire.

JRinElginTX · Apr 16, 2014

That was the setup she came with when I bought her. No doubt it was set up incorrectly. I'm going to rewire according to the diagram. However the wire going back to the ignition switch passes through something else a (LARRP?) Not too sure what that is. Thanks again and I'll send pics back once we have it completed. Also, will change out the rubber gas line back to metal, that was also a 'modification' when I bought it.

JMOR · Apr 16, 2014

(quoted from post at 20:01:41 04/16/14) That was the setup she came with when I bought her. No doubt it was set up incorrectly. I'm going to rewire according to the diagram. However the wire going back to the ignition switch passes through something else a (LARRP?) Not too sure what that is. Thanks again and I'll send pics back once we have it completed. Also, will change out the rubber gas line back to metal, that was also a 'modification' when I bought it.

LARRP" is 'idiot lamp", a small light bulb, such as a #194, or you can use a resistor or a diode.

JRinElginTX · Apr 16, 2014

Would this old resistor work that is below the ammeter instead of using a diode or light? It might be the original, but I'm not sure. Thanks again!

JMOR · Apr 17, 2014

(quoted from post at 00:07:13 04/17/14) Would this old resistor work that is below the ammeter instead of using a diode or light? It might be the original, but I'm not sure. Thanks again!

ill not, because the value is far too small, less than an Ohm, and you need about 10 Ohms or more.

Headlights kill engine

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