TRX420FM 2007 no spark

[jeepwm69 7,731]

14 hours ago, Wolf said:

Do any of you know how to open the grey P33 ECU connector apart to be able to inspect and repalce a pion? wolf

Now you're getting into the "professional" electric work.

 

I'm a "snip and bypass" type guy. 

 

Let's see if we can get @Melatv to chime in, or maybe @retro

 

The TP (throttle position) sensor is on the side of the throttle body/"carb" assembly.

[Wolf 1]

1 hour ago, jeepwm69 said:

Now you're getting into the "professional" electric work.

 

I'm a "snip and bypass" type guy. 

 

Let's see if we can get @Melatv to chime in, or maybe @retro

 

The TP (throttle position) sensor is on the side of the throttle body/"carb" assembly.

 

[Wolf 1]

I pushed the g/y wire into the grey connecter by about 4mm and low and behold I got continuity back to the coil area of that wire. So this is a problem.  How to fix it permanently is the next project.  Tracking down unconnected wires is quite a challenge and really time consuming. I am hopeful that this find will solve my no spark issue.  Wolf 

[jeepwm69 7,731]

1 hour ago, Wolf said:

I pushed the g/y wire into the grey connecter by about 4mm and low and behold I got continuity back to the coil area of that wire. So this is a problem.  How to fix it permanently is the next project.  Tracking down unconnected wires is quite a challenge and really time consuming. I am hopeful that this find will solve my no spark issue.  Wolf 

 

Get some CRC contact cleaner and hose those connections out really well. 

[Wolf 1]

I was procrastinating to see if I actually had spark or not; primarily because I had no next step idea or plan should I fail again. So today I finally verified that indeed we have spark! One, one frigging wire was the problem after all! Looking at the B11 connector all looked OK until you did a continuity test which failed. The most helpful diagram was not the wiring diagram ( which is virtually impossible to read on a computer screen) but a diagram in the "fuel" section in Chapter 6 page 8 that listed 19 of the 33 "B" pins on the P33 grey CDI connector. I tried to copy that page but was not able too. It identified the pin number and its function. B11 is identified as "ignition" . Stuffing the G/Y back into the connector is not a permanent fix. I am looking to buy the P33 Sumitomo connector to learn how to take it appart. There is no on line video of that specific connector. I tested each of the 33 pins for volatge first, then resitance on the remaing pins and finally ground on the pins with no volatge or resistance.  This list is not complete I am sure BUT pins 1,19, 21 and 33 had battery voltage, pins 10,13 22 has resitance. I never got any good other readinds on the remaining pins. I assume they get input from various sensors when the engine is running. Well now on to putting everything cack where it belongs. I hope some of my post will be of help to others. wolf

[jeepwm69 7,731]

21 hours ago, Wolf said:

I was procrastinating to see if I actually had spark or not; primarily because I had no next step idea or plan should I fail again. So today I finally verified that indeed we have spark! One, one frigging wire was the problem after all! Looking at the B11 connector all looked OK until you did a continuity test which failed. The most helpful diagram was not the wiring diagram ( which is virtually impossible to read on a computer screen) but a diagram in the "fuel" section in Chapter 6 page 8 that listed 19 of the 33 "B" pins on the P33 grey CDI connector. I tried to copy that page but was not able too. It identified the pin number and its function. B11 is identified as "ignition" . Stuffing the G/Y back into the connector is not a permanent fix. I am looking to buy the P33 Sumitomo connector to learn how to take it appart. There is no on line video of that specific connector. I tested each of the 33 pins for volatge first, then resitance on the remaing pins and finally ground on the pins with no volatge or resistance.  This list is not complete I am sure BUT pins 1,19, 21 and 33 had battery voltage, pins 10,13 22 has resitance. I never got any good other readinds on the remaining pins. I assume they get input from various sensors when the engine is running. Well now on to putting everything cack where it belongs. I hope some of my post will be of help to others. wolf

 

First off, glad you found it.  I likely would have thrown a used wiring harness at it before I had the patience to find the problem.

 

Thanks very much for posting up what you found too.  The biggest benefit of the forums vs Facebook groups is threads like this are much easier to find and read, whereas when something like this gets posted to social media, it disappears or is hard to find using search engines.  Hopefully your thread will help someone else with similar issues in the future.

 

Now, when you figure out how to redo that pin, let us know!  I guess one option would be to get a connector off of a junk wiring harness and splice all those wires a little ways away from the connector. 

[redhulk2085 0]

Hey guys this is Redhulk2085. I recently just bought a 2007 Honda TRX420 TM model I have no spark and no power to the fuel pump when I test the black and white wire to the ignition it shows that there is power the light comes on but when I hook it up to my positive to test the ground I'm not receiving any signal or light flashing on my circuit tester can anybody help me figure this problem out I have been all over this thing with the multi reader and this circuit tester light also does the rectifier need to be grounded to the frame

[Wolf 1]

My issue was no spark that turned out to be a loose connection at the computer.  I think it was #11 connection that went to the coil. I sold the 2007 so I cannot verify your request. Sorry, wolf 

[redhulk2085 0]

What is the #11 connection.

[Wolf 1]

The cdi box (computer ) has ?33 wires going to it. Every connection has a number . I think each row has 11 connections and you have 3 rows. The last wire on row number 1 is the #11 connection that provides power to the coil. Wolf 

[redhulk2085 0]

Ok thanks 

[redhulk2085 0]

Is the g/y to the coil a hot or ground wire. Because I can't get anything from it.

[redhulk2085 0]

I have a question for someone if anyone can help please do just bought a new ignition switch for my 2007 Honda TRX420TM model. I connected the new key switch in the neutral light came on and it cranks but when I turn the key over to the on position it does nothing can somebody help me with that.

[redhulk2085 0]

Sorry y'all have one more question when my coil pack is plugged in are both sides the green and the yellow and the black and the red. They are both showing to be hot when it is plugged in is this correct.