No spark, 2013 500 Foreman ES (now not fixed again)

[retro 4,048]

5 hours ago, jeepwm69 said:

Battery shows 11.7 V at the coil, 12.41 V directly off the battery

 

The battery is low, should be 12.6 volts or higher. The 7/10s of a volt drop (from 12.41 across the battery) at the Red/Black coil terminal is a problem though. Check fuse sockets for overheating and unplug/plug back in harness connectors in case there is a bad connection. Also check the handlebar kill switch, there should be battery voltage coming out of it.... it's a black/white wire if i remember right. The grounds are good right?

[jeepwm69 7,611]

13 minutes ago, retro said:

 

The battery is low, should be 12.6 volts or higher. The 7/10s of a volt drop (from 12.41 across the battery) at the Red/Black coil terminal is a problem though. Check fuse sockets for overheating and unplug/plug back in harness connectors in case there is a bad connection. Also check the handlebar kill switch, there should be battery voltage coming out of it.... it's a black/white wire if i remember right. The grounds are good right?

i haven’t checked grounds.  Probably should.  This machine looks new, like it’s never been in the mud, and has been stored inside.  No corrosion anywhere on it (at least that I can see) but I’m going to have to check everything obviously.

[retro 4,048]

2013 Foreman might have seen a major change in the ignition circuit ECM/PCM, as the 420 Ranchers wiring are entirely different from the Foreman models and the 2012 Foreman wiring differs from the 2014 foreman wiring. I don't have a 2013 diagram for reference, so lets try something, see if we can find out which manual to use for reference....

 

Using your multimeter, key turned on, measure DC volts with the red meter lead on the coil Green/yellow terminal and the black meter lead on the Red/black terminal. Is there positive (+) battery voltage? If so what is the measurement?

 

Then swap your meter leads so the red lead is on the Red/black coil terminal and black lead is on the Green/yellow terminal. Is there positive (+) battery voltage? If so what is the measurement?

[jeepwm69 7,611]

I'll try that after work.

 

2012-2013 use the same wiring harness, ECU, and coil.  The 2012-2013 Foreman was a bit of a "transition model" and that model was a two year only run until the "new body style" Foreman came out in 2014.

[retro 4,048]

Ok then, after you check the initial voltage at the coil as described above, try checking the peak voltage at the coil while connecting the red PVA lead to the Green/yellow terminal and the black PVA lead on the Red/black terminal. Let me know those results.

[jeepwm69 7,611]

8 hours ago, retro said:

2013 Foreman might have seen a major change in the ignition circuit ECM/PCM, as the 420 Ranchers wiring are entirely different from the Foreman models and the 2012 Foreman wiring differs from the 2014 foreman wiring. I don't have a 2013 diagram for reference, so lets try something, see if we can find out which manual to use for reference....

 

Using your multimeter, key turned on, measure DC volts with the red meter lead on the coil Green/yellow terminal and the black meter lead on the Red/black terminal. Is there positive (+) battery voltage? If so what is the measurement?

 

Then swap your meter leads so the red lead is on the Red/black coil terminal and black lead is on the Green/yellow terminal. Is there positive (+) battery voltage? If so what is the measurement?

-11.24

 

11.24

 

 

[jeepwm69 7,611]

7 hours ago, retro said:

Ok then, after you check the initial voltage at the coil as described above, try checking the peak voltage at the coil while connecting the red PVA lead to the Green/yellow terminal and the black PVA lead on the Red/black terminal. Let me know those results.

 

It started off at like -.8 and it has been dropping the longer it’s connected to where it is now down to -.15 and still dropping, but the drop off rate has slowed the longer it is connected

 

Almost stopped at -.13

[jeepwm69 7,611]

Battery is still at 12.31 V and I’ve had it connected to a tender

[jeepwm69 7,611]

Coil is hot to the touch after I tried to crank it

[retro 4,048]

3 hours ago, jeepwm69 said:

11.24

 

This is a problem, it should match battery voltage.

 

3 hours ago, jeepwm69 said:

Battery is still at 12.31 V and I’ve had it connected to a tender

 

This is a problem too, the battery voltage should be above 13 volts with a tender on it.

 

3 hours ago, jeepwm69 said:

Coil is hot to the touch after I tried to crank it

 

This is a bad sign too.

 

So it looks like the battery is being drained by something, or it is junk. The 9/10s volt drop across the coil is a problem and the coil should not be getting hot while cranking. Possibly the coil has shorted primary windings or the harness grounds are loose/dirty. Check the ignition switch and the handlebar kill switch too.

 

3 hours ago, jeepwm69 said:

It started off at like -.8 and it has been dropping the longer it’s connected to where it is now down to -.15 and still dropping, but the drop off rate has slowed the longer it is connected

 

Almost stopped at -.13

 

Try swapping PVA leads.... put the red PVA lead on the Red/black coil terminal and put the black PVA lead on the Green/yellow coil terminal and crank over the motor with the key on. Let me know those results.

[retro 4,048]

You can disconnect the positive battery cable and set your multimeter up to measure amps current with the red meter lead on the positive battery post and the black meter lead on the positive battery cable. If there is any current with the key off, unplug (& plug back in) component connectors one at a time until you find the culprit. Note that the display meter may draw a milliamp or so while the key is off - thats normal.

[jeepwm69 7,611]

Wonder if the regulator is shot?   That's what I usually see when a battery is being drained anyhow.

 

I'll try measuring for drain, and see what I find.  Fuse box looks brand freaking new, no corrosion or signs of heat at all there. 

 

I have a good battery I can slap on there.  The battery on the machine was low when I picked it up, so it is likely near the end of its useful life.

[jeepwm69 7,611]

On 2/25/2024 at 1:53 PM, jeepwm69 said:

Fuel pump Clicks on

 

Battery shows 11.7 V at the coil, 12.41 V directly off the battery

 

.26 V on the green yellow

So looking at this again, I had a loose battery connection on the positive battery terminal. Tightened it up. 12.65 V on the battery at rest. 11.02 at the coil. When I crank it drops down to about 9.5v at the coil.

 

Going to clean up grounds, and check voltage at the on off switch now

[jeepwm69 7,611]

11.65 v on the black/white wire in the off/on/off switch on the handlebars.

 

 

[jeepwm69 7,611]

Also of note, checking voltage in the fuse box. Main 30amp fuse shows 12.24 V. 10A ignition fuse only shows 11.78 V.

 

Possible when that coil shorted to the exhaust that it partially burnt up a wire somewhere in the ignition circuit?

 

Pull the 10a ignition fuse and checked voltage with my volt meter on the hot side. 12.42V. 
 

When I plug the fuse back in it drops to like 11.28 V on both sides of the fuse. That will be indicative of a drain somewhere correct?

[retro 4,048]

Yeah it looks like there is a possible current drain somewhere in the ignition circuit. If battery voltage goes through the Ignition switch before reaching the 10 amp fuse (as the diagram shows) then the drain is downstream from the ignition switch and the 10 amp fuse.

 

[jeepwm69 7,611]

Looks like that’s pointing to the ECU again?  I’ll try unplugging the ECU tomorrow and see what that nets on the ignition fuse and the stop switch 

 

[jeepwm69 7,611]

OK @retro, tell me if my thought process here is correct.

 

12.7 V at battery now. I’ve had it on a tender. 
 

I unplugged the gray connector on the ECU and checked the black/red wire going to ECU. 

12.7v

 

then I checked the black red wire at the coil which is supposed to come off of that same black and red wire going into the ECU and got 11.5 V

 

 

So do I have a bad ECU or do you think of wires burnt somewhere in the middle or ?

 

 

[_Wilson_™ 6,567]

Ya know something ? You'll be an electric wizard after this.....  

[retro 4,048]

6 hours ago, jeepwm69 said:

12.7 V at battery now. I’ve had it on a tender. 
 

I unplugged the gray connector on the ECU and checked the black/red wire going to ECU. 

12.7v

 

then I checked the black red wire at the coil which is supposed to come off of that same black and red wire going into the ECU and got 11.5 V

 

It looks like a wiring issue to me, since you had the gray connector unplugged from the ECU and still measured a 1 volt drop at the Bl/R coil terminal.

 

Check out the wiring diagram below.... trace the coil Bl/R wire and notice it joins the Fuel injector Bl/R wire inside the wiring harness. Then that Bl/R wire continues to J/C 2 junction connector where it is joined with fuel pump Bl/R, power Bl/R, DLC Bl/R, ECM Bl/R etc.

 

Unplug and check voltage at the Fuel injector, in case the issue is the internal harness junction where the coil BL/R joins the Fuel injector BL/R. I'd put my money on that internal harness crimp joint at this point.... but if the Fuel injector Bl/R measures the same voltage drop as the coil Bl/R, then check voltage on all of the BL/R wires inside the junction connector if you can.

 

I am working on a major bathroom demo & enlarge/replace project for my daughter so I can't be here very often, but I'll try to check back here at  least once a day. Have fun tracing!

 

[jeepwm69 7,611]

10 hours ago, retro said:

 

It looks like a wiring issue to me, since you had the gray connector unplugged from the ECU and still measured a 1 volt drop at the Bl/R coil terminal.

 

Check out the wiring diagram below.... trace the coil Bl/R wire and notice it joins the Fuel injector Bl/R wire inside the wiring harness. Then that Bl/R wire continues to J/C 2 junction connector where it is joined with fuel pump Bl/R, power Bl/R, DLC Bl/R, ECM Bl/R etc.

 

Unplug and check voltage at the Fuel injector, in case the issue is the internal harness junction where the coil BL/R joins the Fuel injector BL/R. I'd put my money on that internal harness crimp joint at this point.... but if the Fuel injector Bl/R measures the same voltage drop as the coil Bl/R, then check voltage on all of the BL/R wires inside the junction connector if you can.

 

I am working on a major bathroom demo & enlarge/replace project for my daughter so I can't be here very often, but I'll try to check back here at  least once a day. Have fun tracing!

 

 

To clarify, when I measured at the coil, that was with the ECU plugged back in.  I think with the ECU unplugged I would get no voltage at the coil, correct?   I'll have to double check that after work. 

 

And no hurry on the replies Retro.  I know you have RLS to do, as do I.  I'm troubleshooting this one a bit at a time as time permits.

[retro 4,048]

2 hours ago, jeepwm69 said:

To clarify, when I measured at the coil, that was with the ECU plugged back in.  I think with the ECU unplugged I would get no voltage at the coil, correct?

 

Even with the ECM gray connector unplugged there should be battery voltage at the coil, fuel injector, display meter, DLC connector, ECM gray connector, ignition switch, etc. since all of those Bl/R wires are fed battery voltage at the JC 2 junction connector. Hopefully the issue is as easy to trace down as it logically sounds.  

[jeepwm69 7,611]

Gotcha!   Looking at the wiring diagram you posted above it did look like a wire Y'ing off the black/red before it went to the ECU, but I don't speak electrical, much less read diagrams!

[jeepwm69 7,611]

So I’ve been going from one into the other on this Foreman following the black/red wire, and as soon as I put the ignition fuse in I get a voltage drop.  I started unplugging components wanted a time and measuring the black and red wire at the fuse box to see if the voltage drop had gone away, and when I unplugged the black and red coil wire and measured voltage there with the coil unplugged, it has battery voltage there. 

I had been pulling the two coil wires partially off of the spade connectors just enough to get my voltmeter leads on to measure for voltage with the coil still connected.

 

@retro, you mentioned a shorted coil.  Does this sound right?
 

I’m going to look in the morning in the factory service manual and see if there is a procedure for testing the coil, but it appears I might’ve gotten a rare bad part from PSN.

[retro 4,048]

Yeah it sounds like the coil windings are shorted. The manual does not list resistance specs for the coil so the only way to know for sure is plug another coil in.