retro

Ok, both of those measurements are good. Just two more tests though ok...? I still have one of those nagging "what if" questions rattling around in my head. :) Plug everything in, Ignition key on, multimeter set to DC volts mode. Poke your red meter lead under the boot on the Black/yellow wire terminal on the Ignition coil and hold your black meter lead on frame ground while cranking the motor over with the starter. Let me know if you see DC volts measured during the test (and if so the reading). If no DC voltage is seen then you can try tapping on the CDI (pretty sharply, but not so hard that you break it) a few times with a plastic screwdriver handle while you are cranking the motor over with the starter to see if you can get it to make spark intermittently.

Smarter than the average bear eh booboo!!!!

YUP! Truth on all the points you made!!! We gotta put all corporate gubmints into disappeared mode. Along with money too. Well you think that electrical stuff is voodoo to you, but I think that's a pretty humble take. You're good at fixing everything you are challenged by once you understand it. You'll soon be an electrical wizard me thinks. Hope you can find an AMPS meter that snaps right in to that case.

Yeah, the controller design that senses low battery voltage before they'll kick on are poorly thought out designs. They won't kick on unless the battery is partially charged. They ignore a completely dead one. I see the same designs on some AA NiMh battery chargers and on many LiPo battery chargers too. They suck because the main design criteria for component selection is to be as cheap to manufacture as possible. Old stuff is usually better stuff because function was valued more than production cost prior to the repugnicans teardown (moved everything to the far east countries where slave/child labor costs are almost free) of USA manufacturing. I've only seen a battery go to reverse polarity once. It happened to my Kawasaki dirt bike battery when I was kid. I blew both ends off of that battery when it exploded after I jumper cabled it to a car battery, trying to flip the polarity back. :)

I say let him finish it man.... Knowledge isn't free and he is the only one willing to pay the price, then he's sharing his new knowledge with us -- so we are getting it all for free! Hammer down Jeep!

So as you said apparently the Schumacher is working (somewhat at least), but the amp meter doesn't seem to be working since you can't get the needle to wiggle off of zero. That Amp meter is easy to replace and you can probably find them On eBay for cheap. But first lets learn a bit more about which type of charge controller you're working with. There are two basic types of charge controllers in use in Automatic battery chargers. The most simple and inexpensive charge controller just monitors the battery voltage while charging and shuts off the output when the battery reaches a certain voltage threshold. The simple type provides charge voltage and current to the battery clamps at all times, even when the battery clamps are not connected to a battery. The more complex and more expensive type Automatic charge controller does not provide any output to the battery clamps until the clamps are connected to a battery, because the controller must sense a low (below fully charged battery voltage threshold) battery voltage before the controller will kick on. You can learn which type of controller you're working with by quickly sparking the red and black battery clamps together (shorting them together quickly as you can - don't hold them together) while they're not connected to a battery. If sparks fly from the clamps then you're working with the simple and inexpensive type controller, and sparks flying indicates that the charger is working. Try this test on 10 Amps Manual mode, then again on Automatic mode. Let me know what happens. If you see sparks fly but the Amps meter doesn't jump toward max scale then the Amps meter is definitely junk. Then measure DC volts across the battery clamps with your meter while the clamps are not connected to a battery. Then switch your meter to AC volts mode and measure again. Let me know what those two measurements are.

You can put your multimeter on Amps mode, move your Red multimeter lead to the Amps socket on your meter (if applicable), unplug the two wires that go to the Amp meter on the Schumacher and poke a multimeter lead into each spade connector on those two wires to measure the charge current going into your ATV battery. If you get a low amps reading (1 or 2 amps? Depends on the charge level in the battery how much current it will accept) then you can assume that the Amp meter in the Schumacher is dead. I would check that Amp gauge before going any further. It looks like there is a half-wave rectifier diode mounted inside on the rear panel. It looks like there is another diode (single spade terminal, White/black wire plugged into it) mounted on the rear panel to the right (as viewed in the photo) of the half-wave rectifier. That diode is probably used for reverse-polarity (allows you to connect the charger leads up backwards on a battery, dummy-proofing) protection, although I can't tell where that White/black wire goes to, so I could have those two diodes mixed up. You can use an old toothbrush and some rubbing alcohol to clean up that circuit board. You can test those two diodes too, by setting your meter to resistance mode (or diode test mode if your meter has that feature), disconnect the wires from them -- and for the diode that has two soldered terminals, measure between the two terminals on the diode with the wires disconnected. Swap your meter leads (opposite polarity) and measure again across those two terminals. If that diode conducts when measured one way, but does not conduct when measuring with opposite polarity (two meter leads swapped, then that diode tests good. If the diode conducts on both polarity's then it tests shorted and is junk. If it does not conduct on either polarity then it tests popped open and is junk. Test the same way on the diode with the White/black wire plugged into it, but since that diode has only one terminal, the case provides it's ground where it is mounted. So one lead on the terminal, the other lead on case ground when measuring. Swap the meter leads to measure opposite polarity.

Yeah, the used CDI appears to be dead. Lets complete the tests on the CDI connector before you replace that CDI though. With the CDI unplugged, your meter on DC volts mode, Ignition key on, measure DC volts between the Black/green wire terminal inside the CDI harness connector and frame ground. You should see battery voltage. Last one.... CDI unplugged, Ignition key off, multimeter in resistance mode, measure resistance between the Black/yellow wire terminal inside the CDI harness connector and frame ground. Report back with that measurement.

Great! That's the best we could hope for since the response time of a multimeter is very slow.... the AC voltage pulse is so narrow and so brief that even the quickest responding multimeters have difficulty recording those voltage pulses. That's why a peak voltage adapter is generally required in order to perform that test. Since you were able to see the pulses occurring that means the Pulse Generator is working. The next test is similar.... we gonna try to measure for AC volts pulses on the ignition coil primary terminal. Plug the CDI back in, set your multimeter to AC volts, turn the Ignition on, hold the red multimeter lead onto the Black/yellow wire terminal on the Ignition coil (do not unplug the Black/yellow wire from the coil, just slip your red lead under the rubber boot to touch the terminal) and hold your black meter lead on frame ground. While holding your meter leads in place crank the motor over with the starter for a few seconds. We are looking for pulses measuring 100 volts AC peaks, or higher. But we'll call the CDI good if your meter attempts to record AC voltage pulses. EDIT: Make sure the spark plug is plugged into the spark plug cable and is grounded on the cylinder head while cranking the motor over.

Did the 0.24 volts AC readings appear in pulses on your meter?

If you see any pulses reading above zero volts AC appear on your multimeter while cranking the motor over then the Pulse Generator is probably working right and we can move on to the next test.

Ok the next test may not be possible.... this generally requires a Peak Voltage adapter, but lets talk about it. Do you have a high quality multimeter? Does your multimeter have a Min/Max button on it? Or a Capture button feature? If so, set your multimeter to AC volts mode and enable the "Max" button on your multimeter (in hopes that you might capture a weak AC voltage spike). Turn the Ignition key on, hold the red multimeter lead onto the Blue/yellow wire terminal and hold the black multimeter lead onto the Green/white wire terminal inside the CDI connector. While holding your multimeter leads on those two terminals depress the starter button and crank the motor over for a few seconds. We are looking for 0.7 volts AC, minimum.

Ok, with the key off, measure resistance between the Blue/yellow wire terminal and the Green/white wire terminal inside the CDI connector. You're looking for about 330 ohms resistance give or take....

Aye! I screwed that up big time! I apologize, I don't know what I was thinking when I typed those instructions, but I definitely advised you wrong! Ok, still got no spark right?

@oilcanboyd, you wouldn't by chance be known as Oil Can Boyd the MLB pitcher would you?

My guess is it's coming from the exhaust as well. Exactly where I don't know.... could be a baffle inside the muffler has come loose from the muffler body or it could be the heat shield creeping back and forth against the header pipe due to expansion/contraction. I'd remove the heat shield to see if the sound goes away. If it does not then I'd blame it on a baffle inside the muffler.

Maybe the Green/white wire is good until it reaches the CDI.... Maybe the wire is broken loose from the terminal inside the CDI connector? That's why you need to verify ground from inside the CDI harness connector, not from the bare spot on that wire. Or maybe I am just misunderstanding you.... :)

Do you have continuity from the Green/white wire terminal inside the CDI harness connector to frame ground? Because if that CDI connector terminal is grounded then you should measure battery voltage between the Black/white terminal and the Green/white terminal inside the CDI connector. The Black/white is the positive (poke your Red multimeter lead into the Black/white wire terminal) and the Green/white is the negative (poke your Black multimeter lead into the Black/white wire terminal). Multimeter in DC volts mode, Ignition key on, Run/Stop switch in the "Run" position.

It's possible Jeep, that the voltage regulator inside your Schumacher may still be functional.... you won't know until the fried bridge rectifier is replaced. It likely got fried when the bridge rectifier failed, but it's certainty for failure depends on whether the bridge diodes shorted out or popped the circuit open. If the diodes popped open then the regulator ceased to be supplied with voltage, which means that it could not have been fried by unrectified AC voltage. Fingers crossed. :)

Sorry Jeep, I didn't see this thread yesterday or I would have jumped in right away. First let me explain the differences in battery charger types and their components. Full manual chargers are the simplest design, they usually have just two parts in the case; a stepdown high output current capacity transformer, and either a half-wave rectifier configuration (one diode), or a full-wave bridge rectifier diodes configuration (4 diodes). The transformer used in all battery charger types just steps down the 115 volts AC input to produce an output AC voltage that is a slightly higher voltage than a fully charged battery can tolerate without destroying the battery during a normal charge cycle. For instance, my purchased in 1993 Schumacher full manual (just has a mechanical timer controlling it) charger transformer outputs 17 volts AC @115 volts AC input. Since it is a full manual type the user must monitor battery voltage while charging and stop the charging cycle when the battery has reached a fully charged condition. That lil' bugger can boil a flooded lead-acid battery dry if it is allowed to continue to charge way beyond a fully-charged condition. It is not intended to charge AGM type batteries, the output voltage is way too high, so it can destroy an AGM if the user allows the AGM to continue to be charging beyond 14.7 volts. I love manual chargers because I want to have full control over the charge cycle.... If I feel like I need to bring an aging battery up to a low boil (for cell voltage equalization and to shed sulfates from the plates) I can do that with a full manual charger. I won't buy an automatic charger (they taper and shut down the charge cycle at 14.7 volts) and I refuse to use one where I have a manual charger option. The rectifier diode configuration in battery chargers converts the transformer AC output voltage into a DC voltage that the battery can accept. A half-wave rectifier consists of one diode (two diodes are used in some configurations), which converts just one half of the AC sine wave into DC. They work by not conducting any current at all while the AC sine wave cycle is in it's lower wave state (negative polarity) and begin to conduct current only while the AC sine wave is in it's upper wave state (positive polarity). Using an oscilloscope you can view an AC sine wave pattern alternating from positive polarity through negative polarity and back through positive polarity at 60 cycles per second. So a half-wave rectifier only conducts current during half of the available AC cycle, which results in the production of pulsating DC. It's common to find half-wave rectifiers mounted inside older model full manual chargers produced decades ago, because they were cheaper to produce than full-wave rectified units (1 diodes vs 4 diodes). Nowadays diodes are inexpensive, so modern chargers often times have full-wave bridge rectifiers inside the case because they're more efficient units. This is what a half-wave rectifier circuit looks like: Full-wave bridge rectifiers are a requirement for automatic chargers though, because auto units have a solid state DC voltage regulator added inside the case which monitors the battery voltage during each charging cycle and tapers off the rate of charge from a high to low charge rate (as the battery approaches it's full charge condition), then usually shuts off the charging output completely once the battery reaches full charge (usually preset at 14.7 volts shutoff for a 12 volt battery) condition. The DC voltage regulator can only function if it's input supply voltage is (almost) pure DC (minimum residual AC when viewed on an oscilloscope). The regulator cannot function if there is AC voltage supplying it or if the supply is pulsating DC. So automatic chargers have a full-wave bridge rectifier inside the case which works to output (close to) pure DC by conducting current on both the positive polarity portion of the sine wave and the negative polarity portion of the sine wave output by the transformer. Modern automatic chargers usually have a filter capacitor connected into the output immediately following the full-wave bridge rectifier, which smooths out the DC supply for the voltage regulator, by absorbing the peaks of the full-wave signal (which results in a slight increase in output voltage due to the smoothing effect). This is what a full-wave bridge rectifier circuit looks like: The Schumacher unit you have in your pic likely has a fried voltage regulator in it that was killed by the failed bridge rectifier. The transformer is still good, so the unit can be fixed by replacing the full-wave bridge rectifier with a new one (depending on the design of that unit you might need two bridge rectifiers, one for 10 amps output mode and one for 2 amps output mode -- otherwise the voltage regulator featured the 10/2 amps output options). Just leave the Auto/Manual switch in the Manual position and it will work again. You don't need the Auto feature.... just don't leave the charger unattended. Old stuff is the best stuff, don't throw that charger away! Here ya go, they're cheap! You can afford to buy two or three of them (I keep them in stock) in case ya gotta fix another unit someday! (eBay) Bridge Rectifier, Single Phase, 50 V, 25 A, Module, 1.1 V, 4 Pins GBPC25005+ If you need any help getting it going again, take the top of the case off and shoot me a few pics of the internals. EDIT: This is a better choice than the one I linked above. It is a reputable major brand, so it's not a china knockoff being marketed by a potential liar who could be selling a 10 amp part, but advertising it as a 25 amp part. This one is rated at up to 40 amps too, so it will be more durable and last longer than a 25 amp rectifier. This one costs more, but it's worth more.... (eBay) NTE Electronics NTE5340 BRIDGE RECTIFIER-FULL WAVE SINGLE PHASE 200V 40AMP This is the link to the datasheet for the NTE5340: https://www.nteinc.com/specs/5300to5399/NTE5340.html

Yes. The kill switch just routes battery voltage to power the Ignition module (CDI) while switched to the Run position. So when the kill switch is in the Stop position power is interrupted to the CDI. The starter is not affected. Have you replaced any parts on your Rancher? Are the wiring harnesses in good, undamaged (no rodent chewed wires, no splices etc.) condition?

Ok great! As with the other two tests in that post, I asked you to do the resistance test on the light Blue wire because I wanted to learn whether there are any more open wires in the CDI circuits. Your test (& repair) proves that wire is good. I'll explain the excessive resistance since it's baked into my nature to provide more info than folks care to hear.... :) The CDI controls the Ignition and it also controls the oil cooler fan motor by monitoring the temperature of the motor oil in the motor to start the fan or stop the fan. The Light blue wire you tested had the Oil Temperature sensor still connected in circuit and so if the oil temp sensor was a good one your measurement should have read between 9.5k - 10.5k ohms. Your test proved that the Light Blue wire is good and your repair even improved upon the losses in the wire due to excessive resistance (it was hacked up?) in that wire. However, the oil temp sensor has degraded over the years and is now way out of spec. After the ignition problem is solved you'll need to replace that oil temp sensor. You'll probably need to replace the headlight bulbs as well if they test out blown/open. So we have a Green/white ground wire that is open between the CDI harness connector and the frame ground. If I were you I would remove a small portion of the insulation on that Green/white wire close to, but about 2 inches away from the CDI connector (to give you enough room to seal your work up airtight/watertight). Then test for continuity between the newly bared wire location and the terminal inside the CDI plug to prove that the connector is still good where that wire goes into the back of it. If the wire proves to be connected to the terminal then solder a new wire onto the bare wire location and solder an eyelet terminal onto the other end of the new wire and bolt that new wire to the frame ground that you'll find located near the CDI mounting location. That should fix the missing CDI ground issue..... but we're only half way done tinkering with that ground circuit...... :) Referencing the wiring diagram for your Rancher you'll notice that same Green/white wire also provides the ground for the Ignition Pulse Generator downstream from the CDI connector, (which triggers the CDI to fire off voltage to the Ign. coil which creates the high voltage necessary to cause the spark plug.to fire). You'll also notice that same ground terminal that bolts to the frame provides the ground for the Regulator/Rectifier (Green wire). So.... unplug the 5p Pulse Generator/Stator windings connector and test for continuity between the Green/white wire terminal inside the 5p harness connector and frame ground. Then unplug the Regulator/Rectifier harness connector and test for continuity between the Green wire terminal inside that connector to frame ground. If either one, or both, of those grounds test open then test & make repairs to those connectors/wires similar to the repair you did for the open CDI ground. Let us know how it goes and whether those wiring repairs fix the no-spark issue, or not.... I gotta run out to my shooting range to help my neighbor sight in his new crossbow, so I may be gone for a coupla hours or more. I'll check back in as soon as I can.

Hi RS990, do you have a 350D with no spark? If so start a new thread and include as much info as you can so we can help.

Do you have soldering equipment and some rosin core electrical solder @Chesnuts54? Got some small diameter shrink tubing you can use for sealing up soldered wire connections?

Yeah, the OP replaced both of those parts with used OEM parts from the same year & model Rancher after the original CDI fried. Now after replacing those parts he has found open circuits on the Green/White wire and the Black/Yellow wire in the CDI harness connector. We're trying to test the other wires in the CDI connector now to see whether there are any more open wires in that connector. Now you're all caught up. :)