2000s 520xi engine dies when headlights are turned on

[Bbo44 2]

I have a 2004 (I think) 520xi that I inherited with the house I bought (1067 hours). Cleaning and fixing it up a bit to mow my lawn. Mows great but last night while it was getting dark I noticed anytime I turned the key to the headlight position to turn the headlights on, the engine dies a few seconds later. The headlights do turn on and function but the engine dies 2-3 seconds after I turn the key to that position. It doesn’t cut off immediatly like the key were turned to stop, but actually still runs for a few seconds then dies. Checked fuses and followed wiring. See nothing wrong. Tried unplugging the headlight power to see if it still did it and it does.

 

any help is appreciates

[gwest_ca-(File Mod) 10,496]

Welcome to the forum.

Think I would start with the ignition switch to make sure it functions as it was intended. The I terminal may not be powered consistently in the Lights ON position.

Have a multi-meter or self powered test light?

 

Garry

[953 nut 51,674]

I seem to remember @pullstart having a problem with the ignition switch on onenof the 520XI units.   

    I would just put in a light switch and not use that key function.

[Pullstart 59,705]

 @Bbo44!  The Xi tractors are beasts!  I had an ignition switch issue last fall, but it was damaged by a young small child.  It’s running great now, the headlights are too!

 

 

[Bbo44 2]

59 minutes ago, pullstart said:

 @Bbo44!  The Xi tractors are beasts!  I had an ignition switch issue last fall, but it was damaged by a young small child.  It’s running great now, the headlights are too!

 

 

Thanks everyone! I wasn't expecting such a response so quickly!

 

It really is a beast. started right up after winter and still runs great with over 1000 hours. Seem to have oil leak around the filter and near rear diff Ill have to look at one of these days.  I was suspecting the headlight issue something to do with the ignition switch. I took it out to check for corrosion or anything but it looked fine. Then decided someone smarter than me on here will know what to do. Ill have to take it out again and check to see everything functions as it should on the switch like @gwest_ca mentioned and what you showed in the video. It'll have to wait till Monday when I can a multimeter from work.

 

I just finished mowing the last 2 acres of my property. At first I didn't know how to disable the safety. To be able to keep the mower blades spinning while moving in reverse. Not sure if the light on the dash doesn't work or if I'm doing it wrong. I found it disables it if I turn and hold the key under the seat then start to move backwards, then release. Then it seems that the safety is off until I restart the mower, but the light never illuminates. I thought you could turn it whenever and it would disable it, but that doesn't seem to be the case, for me at least.

[Pullstart 59,705]

This is a magneto ignition, I believe and “off” simply grounds out the mag.  I am wondering if the ignition is grounding out during the light setting...

 

Mine doesn’t have a safety like that, it is a 1998 and might not have it, or it was removed before I took ownership.

 

this forum is like a bunch of family members at the reunion, except the ones you don’t like stay home.

[Bbo44 2]

10 minutes ago, pullstart said:

This is a magneto ignition, I believe and “off” simply grounds out the mag.  I am wondering if the ignition is grounding out during the light setting...

 

Mine doesn’t have a safety like that, it is a 1998 and might not have it, or it was removed before I took ownership.

 

this forum is like a bunch of family members at the reunion, except the ones you don’t like stay home.

Ya... I just find it very odd that if I have it at low throttle, and turn it to headlights, it will keep running for a few seconds before shutting off. Full throttle and mowing it starts shutting off the engine in less than a second. Best part is once the engine shuts off, I can still here the hour meter click and register time while the key is still in the headlight position....After a little while, it stops though.  I cleaned up where the wires ground near the engine thinking it was bad grounding. I did not realize this was a magneto ignition when I first looked at it, but that makes sense now.

 

Luckily they didn't care about safety pre 2000! I believe 2000 is when they started adding this safety switch (I could be wrong). I get the point of it, but it's annoying to me haha.

 

I'm all for that!

[Pullstart 59,705]

Huh.  Let us know how it goes troubleshooting the switch!

[Tractorhead 8,610]

Check if your Safety switch and shutoff switch is handled by an Relais.

Switch on the Key and hit the safety Switch ( Seatswitch) than you have to hear a click noise.

if you now switch to lights and you hear another click, it could be the same issue i had on my 212 Horse when i got it.

 

if i switch on the lights a missing ground passes via the Lightbulbs and switched the Relais to shutoff

when the Chargevoltage reaches 10,8V.

After that the Engine stalls.

 

There was 3 relais in the electric.

a good clean of all the rotten grounds and an exchange of 1 Relais with internal short solved that issue for me.

 

Maybe that helps in search of your Troubles.

 

[gwest_ca-(File Mod) 10,496]

This model does have magneto ignition but uses an ignition switch for battery ignition to control a kill relay for the magneto.

Garry

[Tractorhead 8,610]

 

Take a closer look at the interlock relay K3, that was the relay i meant what causes my problems.

 

[JohnD 145]

Is your battery getting old or this might be a weak alternator?  While the clue about different shutdown at high revs (high current) and low revs (low current) makes me think these guys are on the right track about poor connections, it all starts at the battery/alternator. 

[Bbo44 2]

2 hours ago, JohnD said:

Is your battery getting old or this might be a weak alternator?  While the clue about different shutdown at high revs (high current) and low revs (low current) makes me think these guys are on the right track about poor connections, it all starts at the battery/alternator. 

battery is newer (maybe 2 years old). I forget the date that's on it. But I took it out and stored it for the winter, and when I installed it and fired it up 2 weeks ago it was strong and gave no signs of struggle to crank. I've since started it probably a half dozen times and cut 4 acres of grass with it in the tractor and it still charged. So the battery and alternator should be good to go

[Tractorhead 8,610]

Basically checks

check all you wires and grounds, if they be tight also in their connectors and clean, especially the battery poles.

 

Ground connections shall be well grounded and have no big rustspots below.

If metal oxydes to much, scrap it blank with a little grinding fleece put little Vaseline on the blank to protect the metal

from further rust and screw the ground lines back on.

Check each switch ( pto, seat, clutch) if they work as they should. Terry sent you an link to the Schematics.

 

Check also the fuses and their seats they all must be clean, even so the contacts on the Ignition key.

if verdigris is seen in a copper provided contact areal, it is a problem for conduction,

clean it out and put little vaseline onto to protect the contact surfaces.

Not much of vaseline, just a gently film, nearly invisible.

 

 

 

[Bbo44 2]

So finally got around to testing the switch. Discovered that the R pin loses continuity when switched to the headlight function. I assume R is basically run or engine run. So the switch needs replaced. Is there genuine replacement parts or aftermarket ones that work? The part number on the switch itself is 3497644 which doesn't match any part number in the file that @gwest_ca said earlier. Or is it the 92-6785 part number like this https://www.amazon.com/GENUINE-OEM-TORO-PARTS-SWITCH-IGNITION/dp/B008TSVHPW from amazon. @pullstart did you use an OEM switch or Aftermarket and where did you get it? Id like to use my original TORO keys, the aftermarket ones look to be the same but this is all new to me

 

also want to throw out another question... when at full throttle and trying to go slow around a corner or edge of the house, it likes to buck around and jerks. Can’t keep a constant slow speed. I traced the forward pedal to under the seat where i can’t get to besides the cover right infront of the seat. It also doesn’t like to completely let off of the forward when I release the pedal. I’m guessing the return spring is just worn out.

 

Thanks everyone!

Edited April 26, 2021 by Bbo44

[Pullstart 59,705]

Nice that you found the issue relatively easy!  That switch isn’t the easiest to get to!  I grabbed one off the jungle site.  It came with two metal keys and a fancy water resistant umbrella equipped key as well.

[gwest_ca-(File Mod) 10,496]

This Toro dealer has good prices as a rule and a reasonable flat rate shipping charge so good time to get other parts you need.

https://www.psep1.biz/arinet.asp#/s/TO//92-6785/1/

 

The "R" terminal is for rectifier and the only place the alternator output connects to the battery is through the ignition switch. We do not know how the internal switching is done.

 

Garry

[Bbo44 2]

Received the new ignition switch yesterday and installed! Working great now!

 

Thanks everyone