I am not a good electrical diagnostician. I know on a contemporary vehicle it is normal for there to be a little spark when you attach or detach the ground to the battery, as there is always something on, the clock, the security system, etc. But I don't think there should be a spark on the T, as nothing should be on, assuming all switches are off (headlights and ignition, no brake light switch added yet). But I do get a spark every time i attach / detach the ground strap. The car is not quite drivable yet, It starts fine on the battery, and the generator seems to be doing its job. I have a '21 Touring with a brand new wiring harness from Mac's. It is wired correctly, tight connections, I have gone over it already, every connection is soldered where applicable, even additions I have made. There is no tail light on the car now, the wire is taped and not shorting. The headlights do not work yet, bad ground, and poor connection to the sockets, I have not gotten to them yet, so they are disconnected now. The car does have a distributor, a 20 amp fuse added, and a starter relay added. What should I be looking for?
A short circuit. or posibbly the the ignition is always on? its a pretty simple system, use a multimeter and isolate circuits until you find one thats causing the ground, you should have no connection between the positive and negative leads to the battery.
Have you checked that the cut-out (on the generator) is not stuck closed?
Does it have a cutout or a voltage regulator on the genny? Seems to me you will see a spark with the regulator.
if his cutout was stuck shut i thinkhe would have more of a zorch than a spark.
Has the horn button been installed? I had similar issue with my '24 turns out one of the wires in the horn button was makeing contact to ground
How could I tell the difference between a cut out and a voltage regulator. What is on the car seems to work, but it does not have a Ford script on the cover so it probably has been replaced. The engine came from a gentleman who passed away at least 12 years ago, so who knows how old it is. Yes the horn button has been installed, just last week, but I noticed the spark before.
Doug :Did you turn the engine a little , so the contact points are open in your distributor , perhaps this helps .
Something's on as stated above. I'd go with the terminal block if you can't isolate it any other way. With every thing hooked up as normal ( and sparking at the battery),loosen the screws on the terminal block, one at a time and remove some wires. No spark? Put 'em back & tighten the screw and move to the next one. Every circuit on the car passes through that block if it's wired correctly. When you hit "sparky" you've isolated it.
and this from another thread:
By John F. Regan on Friday, April 15, 2011 - 04:14 pm:
All of our voltage regulators are easily discernible as to 6,8, or 12V as follows:
On the underside of the base the 8V units are stamped with a letter "A" while 12V units are stamped with a letter "B". No stamp at all and it is then a 6V unit. Positive ground Voltage Regulators have a steel washer in place of one of the center insulating washers. As pointed out - a rivet in one of the center locations designates that it is a cutout. Hope this helps.
and for more information, put these words (or something similar) in your "Google" search window, and read lots of interesting things:
"cutout and voltage regulator difference MTFCA"
Okay it has been a while since I brought this up, and I did not have a chance to trouble shoot this specific problem until today. I went off on another of the many tangents of the issues my T needs addressed, along with the issues my neighbor's Model A has had (I keep the A running for my neighbor in exchange for driving it when I want to). The A is a running car, and the running car takes priority over the one which does not, so the T got shelved for a while.
I started as suggested with the terminal block, and unscrewed each screw to find the short. Last one is the generator, and it is/was the problem. The cut out is the issue. From above, this should not be a surprise. The points seam to stick together. They were stuck again after starting and running the engine for a short while.
So, is this repairable, or adjustable, or does it need to be replaced. If it needs to be replaced, I would want to upgrade to either the solid state version, or is the voltage regulator that is available the way to go?
My car is a pile of parts, and authenticity is not an issue. Dependability and safety are my main concerned. My T is titled as a '21 and I don't think there is anything as old as '21 left to it. It came with a '21 engine, and the frame was '21 or older, I would assume the drive train was too. The frame had issues, so it was replaced with a later frame. Drive train is '27, front axle came from a buddy's T which now has a dropped axle, and I'm convinced the body is a '22
A voltage regulator is the only way to go in my opinion. Trouble free once installed, if and only if all electrical items are working on your T.
Electrical troubleshooting on a simple vehicle like a T is childsplay if you don't let it intimidate you. Essentially every circuit (lights, generator, horn, etc., etc. connects to the battery - either directly or to a "bus" wire from the battery (think of it as an extension of the positive battery terminal).
Troubleshooting then, is simply a matter of disconnecting each circuit until you no longer get that spark. A better indicator than a spark is to connect an ammeter between the battery and the battery cable. That way you can know just how much the current drain is and actually see the current drop to zero when you disconnect the offending circuit (make sure the ammeter can carry enough current !). BUT there's nothing wrong with using that spark as an indicator either!
I agree that the generator cutout is the most likely culprit, but if not .... disconnecting each circuit will let you find the problem.
Tap the top of the cutout with a small hammer or vise grips. Do sort of a a "bonk!" with the hammer, not a firm whack. You will hear a metallic "ting!" from inside the cutout, which is the points snapping. Then try your battery cable. You may have to "encourage" the cutout a couple times before the points free up. This is not a permanent cure, but it at least will keep your battery from draining or possibly heating up wires and starting a fire. It is a short-term, get me home kind of fix. The problem lies in the cutout, which may be one of those 1970's cheap off-shore pieces of junk that surface now and again these days.
Sticking cutouts used to be a very common problem in Model A's during the 1970's because off-shore repop cutouts weren't worth a darn. That issue has supposedly been corrected, in addition to cutouts becoming available with diodes. Lots of solutions available now that weren't commonly available in this hobby from vendors 35-40 years ago.
Back in the 50's I drove a Model A that the cutout always stuck closed, my "no money" solution was to leave the cover off the cutout and every time I shut the engine off I would open the hood and manually open the contacts.
Worked for me, YMMV.
I actually have a Knife cut off switch in mine mounted on the fire wall. Just in case.
One problem with a sticking cutout that most people get in trouble with is that they see it as a nuisance rather than a serious problem. Once a cutout starts to stick "closed" it runs the battery down but it also means that the points are crusty, pitted, and dirty and can also stick "open" meaning that when the engine speeds up the cutout contacts physically close but do not make electrical connection and then the generator is running with no load on it and that spells doom for the generator. Cutouts are nasty since if you leave them in place they will bag first your battery and then your generator. At the very least use a diode cutout since then you will only bag the battery if the thing shorts since diodes do not fail open.
A team of technicians is working in a secret testing facility near Leander, Texas to fix this problem of sticking generator cutouts once and for all.
The team has devised an electronic unit that looks just like the metal cover on an original Ford cutout. It contains a microprocessor with one million terrabites of memory. The microprocessor controls a solenoid that is equipped with a depleted uranium mallet.
When the Model T is turned off the microprocessor determines that the generator is no longer turning yet the battery is connected. Through superior powers of its supercomputing capabilities the chip enables the solenoid to whack the bejesus out of the cutout until it releases.
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