Thread: polaris help
02-24-2008, 12:32 AM #1
- Join Date
- Feb 2008
have a problem with my msx110 not getting spark to the rear cylinder. put in a new ecu
02-24-2008, 06:53 AM #2
02-24-2008, 07:23 AM #3
did you try new plugs? have you swapped the coils to see if you get spark? also why did you change the ecu? if you swap the coils and make sure you have a good set of plugs installed and still have no spark on that cylinder you are going to have to get a multi-meter and the wiring diagram. is this a salt water boat or fresh water boat? has it ever been under water? does it run at all? need more information.
Welcome to the Green Hulk!
02-24-2008, 08:39 PM #4
- Join Date
- Feb 2008
02-25-2008, 08:45 AM #5
well it sounds like you have something going on in the wiring harness. you said it is at the rear or pto cylinder right? so i am to assume that you swapped out the coils and the pto coil works on the mag cylinder correct? you never answered my question on why the emm was changed? was this underwater? it is a pretty simple to firgure out what is going on if you understand basic electronics. ok from what i can think off the top of my head there should be three color wires at the coil.
1. green- goes to emm and is your driver wire.
2. black-should have a engine/chassis ground all the time
3.red/purple- should have voltage present when you wake up the system(crank machine or tap start button when lanyard is in)
so do the following:
get a mutli-meter and put it on volts D.C.
get some paperclips or backprobes is you have them.
visually check the terminals and make sure that when you hold the connector that the terminal does not move in connector body and does not have any signs of corrosion. do this at the coil and at the emm on the largest connector.(you will have to unplug all the emm connectors to get to this connector)
while you have the connector off the emm probe and connect your meter to the green wire and the other end to the green wire location at the coil connector. while doing this move the wire around and see if the reading changes. also make sure that you do not hold either end of the meter as you will get a resistance reading.put the meter on OHMS and make sure that you have less than 1 OHM.(be sure to touch the meter leads together and subtract and reading if one is obtained) if you have less than a ohm the wire is good. also make sure that the terminal end is not loose and looks like it is in good shape. if all is good put the connections pack on emm
next put you meter on volts DC. put you lanyard in and backprobe at the pto coil connector on the black and the red/purple. tap the starter button few times to wake up system.you should see battery voltage there. then do the following tests to confirm what you found:
put the meter on ohms and check from engine ground at the battery to the black terminal. should be less than 1 OHM. then while the meter is in the same configuration switch the meter to Volts DC and see what you get. you should get no more than 1 Volt DC of loss. if all this checks out than you have a good ground.
do the same two tests on the red purple wire. go from the red/purple at the pto coil connector to the battery positive. make sure that you have less than 1 OHM of resistance and no less than 1 volt dc of voltage drop. if that checks out ok than you have a good red/purple circut.
if all of the above checks out goos than you most likely have a bad pto coil driver in the emm. was this emm that you put in brand new?
hope this helps and is not to confusing. i need more input from you on your side on some questions that were asked previously and in this test procedure.
Last edited by 2&4strokepolaristech; 02-25-2008 at 08:50 AM.
02-26-2008, 10:13 PM #6
02-26-2008, 10:30 PM #7
- Join Date
- Jul 2007
- near Toronto, Canada
You can not use a multimeter to properly test resistance (ohms) on a circuit that has power. A multimeter can only provide a correct reading for resistance if the circuit is unpowered.
Testing the ground wire (or any wire) for continuity (where low resistance is what you want to find), requires that the power be completely off, or at least one terminal of the battery be disconnected. Otherwise, wire resistance (if present) can appear as small voltage differences, which can confuse the meter, and provide a false ohms reading.
Test for voltage drop with the power connected, for sure, but test for resistance only with the electric power source disconnected, or otherwise out of the circuit under test.
Jay is correct that when testing low ohm ranges, like wires (and some coils), you must first check the meter's own 'zero' reading with the probes touching. Then subtract that reading from any measurements, to get the actual wire resistance value.
02-27-2008, 06:50 AM #8
i have never had any problems with a fluke meter measuring resistance in all my years. as a matter of fact every manufacturer that i have gone to training for and in most every service manual they use fluke meter. it has never lead me down the wrong path. i guess everybody is doing it wrong and i do not know how we all got this far?
hey K447 you take it from here ok! good luck this is part of the reason i do not post as much on here as i use to. EVERYBODY KNOWS BETTER!
Thanks Al I tought it was pretty good to.
Last edited by 2&4strokepolaristech; 02-27-2008 at 06:57 AM.
02-27-2008, 12:22 PM #9
- Join Date
- Jul 2007
- near Toronto, Canada
Part of my background is electrical and electronics, so topics that involve those aspects interest me.
Regarding experience with PWC technology, history, knowledge and effective servicing techniques, obviously yourself and others are way ahead of where I am.
I am not saying that the test sequence described produces incorrect diagnosis.
"... put the meter on ohms and check from engine ground at the battery to the black terminal. should be less than 1 OHM."
Your description of the test for resistance to ground for the black wire was straightforward. My post was merely clarifying that if there was any power present during this test, the resistance value displayed could be inaccurate.
The very next test indicated that power could indeed be present;
"...then while the meter is in the same configuration switch the meter to Volts DC and see what you get. you should get no more than 1 Volt DC of loss.."
This test sequence is relying on the meter's automatic self-protection to avoid meter damage. Which I suppose is just fine, as long what is happening is understood.
Using this technique (making resistance measurements in powered circuits) in other situations could create misleading diagnosis, if it is important that the resistance values displayed be accurate. That is what I was attempting to highlight.
If significant voltage is present in the test you outlined, then the voltage drop test reading will show the problem, and the prior resistance test result is immaterial. If there is no voltage drop at all (zero volts measured), then the resistance measurement can be useful. It is unlikely to be accurate if there was even a small voltage differential present.
My technical point is simply that measuring resistance is the one function a multi-meter does where the meter's own internal battery is supplying low voltage electrical power to the probes (typically under 1 volt, but it can be as much as 3 volts), and measuring the resulting small current flowing through the resistance being tested.
If the wire or circuit being tested has some voltage of its own, the multi-meter cannot accurately measure the resistance, since there are now two voltage sources involved (the meter's internal source and the external battery). A tiny change in voltage seen at the probe tips can create large changes in the displayed resistance.
Many fully automatic multi-meters continually sense the presence of voltage at the probe tips, and disable ohm measurements if voltage is detected, or automatically switch to displaying the voltage at the probes, rather than the resistance. This can confuse the user, if they think they are reading a resistance measurement, when it fact it is a voltage readout they are looking at.
Two of my own Fluke meters do NOT do this, they interpret the external voltage as an incorrect resistance value, and the ohms displayed are completely incorrect. The attached photos clearly show this.
In the old analog dial meter days, touching an ohmmeter to a powered circuit was almost guaranteed to damage the meter. While that problem has been eliminated with the modern automatic mode switching, self protecting multi-meters, it does mean that sometimes the meter is not doing what you think it is, if there is some residual voltage or current present in the circuit.
I have also used Fluke meters for years, and I think they were one of the first reliable meters that self-protected against incorrect mode settings.
Incorrect resistance readings in the presence of external voltage applies to many multi-meters, not just Fluke (which are excellent meters, of course). You cannot accurately measure resistance of a circuit that has voltage or current present at the measuring points.
Attached are two pictures. The first shows an old, nearly dead battery (about 0.8 volts) being tested for resistance. The displayed 12 megohms is incorrect, of course.
The second shows two meters connected together. One meter (Fluke 77) set for ohms, the other (Fluke 23III) shows the voltage present on the probe tips of the first meter (0.761 volts).
I currently have a head cold, and am probably not thinking at 100%. If my post rubbed you the wrong way, or appeared to criticize your expertise, I apologize.
02-27-2008, 09:20 PM #10
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- Feb 2008
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