Yet another wiring question

Fri Feb 14, 2014 5:54 pm

After installing Mr. Brillman's beautiful wiring harness on my '52 cub (with I-wire alternator and 12 volt negative ground), the new battery went dead in a couple of days. With the battery recharged, the tractor starts. Here are the two tests I performed--Please tell me if they mean anything: Both tests were with the positive cable disconnected.
1. I connected my continuity device to each terminal of the tractor's ammeter (one at a time) and to the body of the meter. I did it with ignition switch on and off. No light came on on the continuity meter at any time. That means no short, right?
2. Then I connected one test lead to the negative terminal of the battery and touched the probe to each of the 2 terminals of the ammeter. No light when the switch was off, but the light came on when the ignition switch was on. Does that indicate a short?
Charles

Re: Yet another wiring question

Fri Feb 14, 2014 6:59 pm

I take it you are using a test light to conduct the tests.

In order for the test light to "light" there needs to be a loop (circuit) from the negative to positive terminal on the battery through the test light.

You really didn't explain how you were conducting the tests. Were were the test light leads attached during each test?

Re: Yet another wiring question

Fri Feb 14, 2014 9:27 pm

The way that I see it: If your "continuity device" contains its own power source (battery) and turns the light on to indicate a continuous circuit; and your Cub has a distributor; and the positive lead is disconnected from the battery andthat lead is isolated from the tractor; and the negative lead is connected to the tractor (ground) -- then with the switch on, if the points are closed, you would have continuity. Lack of continuity to the gauge case may indicate that the case may not have a good ground. Try all that again with the coil-to-distributor wire disconnected and isolated.

Bill

Re: Yet another wiring question

Fri Feb 14, 2014 10:40 pm

charlesellis wrote:.....1. I connected my continuity device to each terminal of the tractor's ammeter (one at a time) and to the body of the meter. ...........

Like-em-all wrote:....... Lack of continuity to the gauge case may indicate that the case may not have a good ground. ........
I don't think the ammeter case is "grounded" other than by it's mounting and then it's not an electrical connection. There is no connection between the terminals and case, just between the terminals.

Re: Yet another wiring question

Fri Feb 14, 2014 11:59 pm

If you have access to an ammeter, connect it in series with one of the battery cables and the battery (with everything off). That is, you should be able to determine how much parasitic current drain there is.

Re: Yet another wiring question

Sat Feb 15, 2014 12:00 am

BTW, what sort of wiring harness is "Mr. Brillman's beautiful wiring harness"? Since the Cub didn't come stock with a 1-wire alternator and 12 neg ground, was this harness made up custom for you?

Re: Yet another wiring question

Sat Feb 15, 2014 10:08 am

Thanks for your responses. I'll answer your questions in order.
1. I did use a test light (called continuity tester). I attached the clip to grounds (case of ammeter and neg. terminal of battery.
2. I repainted the dash (and other parts. To do so, I had removed the ammeter. As the terminals pass through a grounded mounting bracket, there is a good chance of a short there. I'm still not sure if that is the case. That is what I was trying to ask. I'll try testing again with coil to distributor wire disconnected.
3. I'll also try my handheld ammeter as Rusty suggested.
4. I told Mr. Brillman (a most patient guy) what I had and he sent me the correct harness--with one lead to the alternator.

Is this forum great, or what?!
Charles

Re: Yet another wiring question

Sat Feb 15, 2014 11:47 am

Sorry to be so dense, but do you have contact info for Mr. Brillman? Thx.

Re: Yet another wiring question

Sat Feb 15, 2014 8:16 pm

charlesellis wrote:..... As the terminals pass through a grounded mounting bracket, there is a good chance of a short there. I'm still not sure if that is the case. ..........
Both studs sticking out the back of the ammeter should have a nylon/plastic/rubber/etc. washer between the nut on the stud and the bracket. There should be a lip on the insulating washer that fits in the hole of the bracket and the stud goes through the lip so the stud can't contact the inside edge of the hole in the bracket. So stacked up from the ammeter out you should have the bracket, the insulating washer with lip, metal washer, nut, wire terminal(s), lock washer, nut. You can use an appropriately sized rubber grommet. Don't need to really clamp down on the bracket just snug it up enough to keep the meter from turning in the hole. Really clamping down on it can deform the insulating washer and short it out.

Re: Yet another wiring question

Sat Feb 15, 2014 8:46 pm

ok... simple test.

to test if there is a draw on the battery when the ign switch is off, simply disconnect the ground wire from the case of the tractor. any sparks when you connect/disconnect it indicates a current draw. you probably would not see any draw on an ammeter, as the draw is probably not enough to deflect the needle.

is your battery new? mag or battery ignition?

Re: Yet another wiring question

Mon Feb 17, 2014 4:35 pm

Here are replies to recent posts:
1. To Scrivet--I used the nylon washers, but as you indicate, it's possible to use them and still have a short. No one has yet addressed my original question: Do the tests I performed (described in my first post--dated Feb. 14) indicate a short?
2. To artc--I have a brand new battery and battery ignition. I'll try the test. But I have on order an analog meter with a band for small amounts of current. Would I set it on milliamps and connect the leads between neg batt terminals and groundwire? Or would it get shorted out? I think that is the test Jay Smith mentioned.
3. To Jay Smith (see #2 above). Brillman has a new catalog out. He has electrical equipment for all sorts of old tractors, trucks and cars. Email is Info@brillman.com. Web site is www.brillman.com I learned of him from this forum.
Charles

Re: Yet another wiring question

Mon Feb 17, 2014 5:22 pm

charlesellis wrote:I have on order an analog meter with a band for small amounts of current. Would I set it on milliamps and connect the leads between neg batt terminals and groundwire?
Use the 20 amp terminals on the multimeter. You can also use a digital multimeter. You are initially looking for a significant amp draw, enough to run down the battery in a short time.

Actually, depending on which style test light you have. Use a test light first before installing a multimeter. You will blow the multimeter's fuse if the amp draw is more than the meter's limit. Surprisingly, the replacement fuse may cost more than the multimeter.

Re: Yet another wiring question

Mon Feb 17, 2014 11:13 pm

Question 1 you are correct.

Question 2 Not enough info about the way the one wire alternator harness is made to give an answer.
2A. One wire alternator is hooked to? Battery cable at starter - Ammeter then back to starter - ammeter then on to battery - somewhere else.
2B. Where is the ignition kill switch getting power from now with the one wire alternator? What else if anything is connected to the input on the kill switch? The other wire on the ignition switch going to the coil is hooked to the pos or neg teminal?
2C. Light switch is hooked to a fuse which gets power from a connection to the ?

Like-em-all wrote:....... Try all that again with the coil-to-distributor wire disconnected and isolated.
What is result of test 2 with ignition switch/coil wire disconnected from coil?

Re: Yet another wiring question

Tue Feb 18, 2014 7:17 am

Did Brillman provide a wiring diagram with the harness?

If so, post a copy of the wiring diagram.

Re: Yet another wiring question

Tue Feb 18, 2014 9:02 am

Brillman did not provide a wiring diagram. Instead, each wire had a number attached. A sheet said what number to attach to each place on the tractor. That's why I'm not sure how to answer Scrivit's questions (Feb. 18) without sitting down with the tractor in front of me. In the meantime I have attached a kill switch to the positive terminal of the battery and a trickle charger.
Charles