Wolf 1 Posted July 19 I am at my wits end trying to get spark on this Rancher that I bought used. The spark plug is new. All the fuses are good. Diodes tested are good. The safety swich has been replaced. The coil test good but I replaced it as well just to be sure. The CDI unit is OEM new. The stator tests good. The pick up coil tests good. I do not have a "peak voltage " tester but may need to get one. If the gap on the pick up is too wide I can see that as a problem. I have not messed with the votage regulator as that should not be involved. I hope that is correect. All the grounds test good. So what am I missing? HELP! wolf Share this post Link to post Share on other sites
Fishfiles 19,776 Posted July 19 Hi Wolf , welcome to the forum , I am not a 420 guy by trade and not 100% sure , that it was a 420 that I was reading about , but recently read a thread that the voltage regulator was the problem for no spark ---- seems you changed everything else ---- someone more knowledgeable than me will come along @retro , it has be theorized , by me , that a bad voltage regulator could possibly cause a no spark on a 420 , does that statement hold water ? Share this post Link to post Share on other sites
Wolf 1 Posted July 19 I have read that in the FOREMAN that it may play a role but not in the RANCHER. I just tested the voltage regulator and it tests OK. So that is not the issue. Thanks for the reply. wolf Share this post Link to post Share on other sites
jeepwm69 7,236 Posted July 20 Do you have 12V on the black/red wire at the coil? @Melatv walked me through all of this when I had a 420. Share this post Link to post Share on other sites
Wolf 1 Posted July 20 The wires going to the coil are green/yellow and black/brown stripe. The g/y is hot with 12 volts plus with ignition on. The blk wire is a ground that tested good to ground. Wolf Share this post Link to post Share on other sites
jeepwm69 7,236 Posted July 20 Sounds like you've covered everything that I would know to try. Maybe @Melatv has an idea. He's been around the last couple of days, so hopefully he'll chime in. @retro might be able to tell you how to cobble up a cheap peak voltage meter. Share this post Link to post Share on other sites
Wolf 1 Posted July 20 I saw a you tube video that shows the DVA circuit. A diode, resistor and capacitor. They sell for $30 on ebay. I may inquiry if a Honda tech locally would do the testing for a fee. The prior owner opened the stator case it is possible that the pickup coil gap is wrong, too wide so the signal to fire never gets to the cdi. The peak meter test should detect that. Stay posted. Wolf Share this post Link to post Share on other sites
Wolf 1 Posted July 31 So I got a DVA adapter to test "peak" voltage The stator Pikup coil reading was supposed to be > 0,7 V . I got 2.3v. So I gues the pick up coil is OK. The volatge on the "hot" primary coil lead reads the battery voltage 12V+ BUT when I crank the engine instaed of get >100Volts it drops to 9.2 volts. . So something is not right there. I will look on Utube to see what I should do next. PS the entire rear end is toast and I am rplacing that as well. wolf Share this post Link to post Share on other sites
Wolf 1 Posted August 7 There is one more safety "switch" on this ATV . The bank angle sensor. If the ATV tips >70 degrees the ignition turns off. I removed the sensor and get > 3volts when the sensor is upright. It is supposed to be 0volts or <0.1 volts. When I tip the sensor I get the expected 12v ( battery voltage). I have ordered a used senor. More later. wolf Share this post Link to post Share on other sites
toodeep 1,737 Posted August 8 3 hours ago, Wolf said: There is one more safety "switch" on this ATV . The bank angle sensor. If the ATV tips >70 degrees the ignition turns off. I removed the sensor and get > 3volts when the sensor is upright. It is supposed to be 0volts or <0.1 volts. When I tip the sensor I get the expected 12v ( battery voltage). I have ordered a used senor. More later. wolf You can bypass the bank angle sensor with a jumper wire on the outer terminals of the connector (harness side of course). A couple of my 420s are running with that deleted because it caused issues. Share this post Link to post Share on other sites
Wolf 1 Posted August 8 Thank you. I will try to jumper it tomorrow. Wolf Share this post Link to post Share on other sites
jeepwm69 7,236 Posted August 8 @1080PowersportsPartsLLC Share this post Link to post Share on other sites
Wolf 1 Posted August 8 15 hours ago, toodeep said: You can bypass the bank angle sensor with a jumper wire on the outer terminals of the connector (harness side of course). A couple of my 420s are running with that deleted because it caused issues. Share this post Link to post Share on other sites
Wolf 1 Posted August 8 I see my connector wires are not the same color as your photo. I have (in order) red black and green. I already blew one 10amp fuse with an ill placed jumper and want to be sure to place the jumper correctly. Is your guess the jumper goes between the red and the green? wolf Share this post Link to post Share on other sites
toodeep 1,737 Posted August 9 Yes, the red and green. The center wire is black with a green stripe if I remember correctly. Share this post Link to post Share on other sites
Wolf 1 Posted August 10 I got busy but did the jumper today and no luck . Still no spark. My peak voltage tester died. I have ordered anothe one and will run through that diagnostic again when the new one arrives. wolf Share this post Link to post Share on other sites
Wolf 1 Posted August 14 So I got a new peak voltage tester and got nothing at the saprk plug ( no surpise there) got battery voltage at the + (GRN/Yellow wire) at the ignition coil that dropped to 9V while cranking the engine. AT the 33P Grey CDI box connector on temianl B23 & B12 got 4.4V consistently and got 4.6 V at the 5P altenator connection (Blue/yellow and Green wires) The spec is >0.7 V. So that is good. There is a line in the manual to check the resistance of the stator yellow wires "Measure the resistance between yellow wire terminals of the altenator side connector. 0.1 to 1 ohm at 68 degrees F)" I do not under stand that. I see everyone checking the stator for continuity but no info on resistance testin or how you do it. What is a "side connector"? Thanks for any help. wolf Share this post Link to post Share on other sites
Wolf 1 Posted August 14 Apologies! I found a motorcycle video that does resistance testing . You test across each yellow terminal ( 1to 2, 1to 3 , 2to3 etc) and I get 0.7ohm . That is in spec 0.1 to 1 ohm..I rechecked the terminal to ground and there was no short. So mesuring wise the stator "tests" good. Someone prior to me has been in the stator and my stator may not be OEM. You always see the warnings "don't get a foreing made part it will screw thisngs up for you." I remain frustrated and confused. wolf Share this post Link to post Share on other sites
Wolf 1 Posted August 14 So let me add some more confusion here. I retested the volatge to the coil primary. Previously I always got battery voltage to the 2 wires. NOW I GET NOTHING. The only thing I have done is yank the wireing harness around to get at various connections. I am thinking I may have a short in the harness. wolf Share this post Link to post Share on other sites
Fishfiles 19,776 Posted August 15 13 hours ago, Wolf said: So let me add some more confusion here. I retested the volatge to the coil primary. Previously I always got battery voltage to the 2 wires. NOW I GET NOTHING. The only thing I have done is yank the wireing harness around to get at various connections. I am thinking I may have a short in the harness. wolf Hi Wolf . I have seen wires get corroded inside the plastic outer covering , you would never know the wire was broken or severely corroded , unless you pull on the wire , the plastic may stretch , also did you open every connector on the harness and clean and apply some dielectric grease to the connector's innards Share this post Link to post Share on other sites
Wolf 1 Posted August 16 Thank you Fishfiles. I am in the process of doing that. wolf Share this post Link to post Share on other sites
jeepwm69 7,236 Posted August 17 Factory service manual should have troubleshooting info, including checking continuity of wires. That's how I found the broken wire going to the shift motor on that Rubicon I had a couple of weeks ago; the FSM specified which pin in the ECU connector went to the shift motor, so I checked for continuity between that pin on the ECU connector and the pin on the shift motor plug, and was able to find the broken wire when one of the wires I tested didn't have continuity. Share this post Link to post Share on other sites
Wolf 1 Posted August 17 The service manual does have troubleshooting but it is a bit arcane and uses a lot of abreviations that a non-professional has to learn. My issue is no spark and I have examined and ruled out so far the coil, stator, pickup (CKP if you prefer), kill switch, and bank angle sensor, P33 connector (multiple pins). I am looking for the TP/MAP sensorand have not yet found it. I will remove the air box for a better view of the top of the engine. Thanks for your interest. wolf Share this post Link to post Share on other sites
Wolf 1 Posted August 17 Some news! I mapped out all the individual 33 pins on the PCM/ECM ( CDI if you prefer) and pin #11 is a G/Y wire that goes to the coil and subsequently to the spark plug. I get an open circut on that wire. I am not very good at electric work. I test that with the ignition off as well as ignition on. There is 12V current on that wire at the coil. Several other pins have current ie.) #1, #19, #21 and #33. I cannot find out if #11 should have 12V or not. I do not see a way to take apart the grey CDI plug. Is there a safe way to run a jumper wire and see if it solves my problem? Share this post Link to post Share on other sites
Wolf 1 Posted August 18 Do any of you know how to open the grey P33 ECU connector apart to be able to inspect and repalce a pion? wolf Share this post Link to post Share on other sites
