Relays and the Onan Powered WH

[boovuc 1,090]

Guys,

 

This is a carry over from my post on my 416 not cranking. (Issue resolved but it triggered another).

 

Has anyone ever had an electrical issue that directly involved the relays on the Onan powered 400/500 Series Tractors?

Readers Digest Version of the issue:

 

If I install both relays in my 416-8 Speed, (1992 Model Year), all is fine until I flick the headlight switch. I then lose my charge gauge and I have no headlights. (The tractor still runs and starts normal). The 15 amp light fuse does NOT blow! If I leave the tractor off for awhile, when started again, the gauge works properly until once again, I flick the headlights on. This condition is resolved by simply leaving the Starter relay out of the socket. Everything works as it should with the relay out. (Only the seat relay is installed).

Read the whole post on the previous 416 not cranking topic to see how I have arrived at the current condition.

 

Any one care to take a stab at this dysfunction?? 

 

Thanks!

[gwest_ca-(File Mod) 11,029]

You can start it with the start relay removed?

or

You start it and then remove the start relay and the lights work normally.

 

Garry

[Martin 2,131]

That's the crazy thing about this Garry, from what we worked out in the other thread, it starts with NO start relay in the socket.......

I still say there is some funny business in the wiring, terminals, connectors, somewhere.......

Sent from my iPhone using Tapatalk

Edited May 5, 2014 by Martin

[boovuc 1,090]

That is correct. It starts without the relay installed. It did both before and after I switched out the fuse block. There was only one relay in the tractor. That was the seat relay.

[Save Old Iron 1,566]

I would love to work with you on this.

 

The only caution I have is the project I am involved with at work will limit my free time over the next few weeks. If once a week response from me is OK, then we can do this together.

[gwest_ca-(File Mod) 11,029]

There should be a tan wire on the S terminal of the ignition switch. Follow the tan wire to see what it is connected to. It should go to the pto switch with the purple wire on it. With pto off the power goes into the purple wire and from there to the clutch switch. Clutch depressed the switch sends the power down the dark blue wire to the start relay coil. Somewhere in here the power is going to the light blue wire that powers the solenoid. Find this problem and the short blowing the fuse may disappear.

 

Disconnect the idiot light panel in case it is rerouting the power but do it with the start relay removed. If it no longer starts you may be getting close.

 

I'm looking at the wiring diagram in the operator manaul

I think there is a mistake in it also. They show both pto switches open with the pto OFF. They should be closed in the pto OFF position. This allows the starter to work and feeds the ignition. Pto ON the ignition should be fed by the seat switch and seat relay.

With the pto ON the way it is illustrated it feeds the ignition and the seat switch has no control over it. Looked at every manual I can find and they are all the same. What am I missing?

 

Garry

[boovuc 1,090]

Hi Garry,

 

I'm not blowing any fuses. I never did with this tractor. Melted fuse yes but they never blew!

With my new fuse holders, I'm not even getting any melting of the actual fuse itself. They all look good and I have started this tractor religiously two to three times a day from when I replaced the bad fuse block on Saturday.

Again, here is what happens:

With the fuses in place and 'BOTH" the start and the seat relay installed, everything starts and runs normal. The charge gauge works, yadda yadda yadda. When I turn on the headlights, they do NOT come on BUT the charge gauge cuts out as if you turned the key off.

The tractor continues to run and will operate in this condition and the battery is charging.

If you turn the tractor off for awhile, (don't know for how long), and go back to it and fire it up...........it starts as it should and the charge gauge works. Turn on the headlights, and the gauge cuts out and I have no lights. The fuse does not blow in the 15 amp light circuit! I think the relay cuts off the power and after it is de-energized by shutting it off, it returns to normal and the gauge works again.

 

If I leave the start relay out of the socket, everything fires up as it should and my headlights and charge gauge work as they should.

Remember that the start relay was NOT in this tractor when I got it and I have had it for over three years.

The rewiring of the fuse block cured the No Starter Engagement Issue that I sought to fix. So far, when I turn the key, there is a slight delay of maybe half of a second where I hear the seat relay close then the starter cracks.

 

There are two things that may be driving this bizarre issue: I have the PTO switch bypassed! Actually, it was bypassed when I got it along with the seat switch. (The neutral switch and clutch switch are still operational).

I see a yellow and an orange wire spliced together below the PTO lever. This is correct for the wires to the PTO switch. (Orange going back to the key).

 

Is having the seat and PTO safety switches bypassed causing the issue of not being able to use a relay in the starter relay socket? (I would think it shouldn't start at all without the relay present).

 

The second possibility is the relay itself. I was told and from what I could see, the tractor would have come with the same relays for both the starter and seat. Is there a different relay that goes to the 4 pin starter circuit verses the 5 pin seat relay circuit? (Only four pins wired for the start relay socket. 5 pins are wired for the seat relay socket).

[gwest_ca-(File Mod) 11,029]

4 wires to the start relay are correct. The 5th pin would be used to power an idot light but they don't monitor the starter.

The 5th pin on the seat relay triggers the seat idot light.

 

With the yellow and orange wires jumpered you should be able to remove the seat relay and still have power to the ignition coli.

 

With the yellow and orange wires jumpered the orange and dark green jumpered for the seat switch have no influence on the seat relay. These power the seat relay coil that closes the relay but the circuit is already powered by the yellow and orange jumper. That is why you should be able to remove the seat relay and still have ignition or remove the seat switch jumper and still have ignition.

 

Do your idiot lights work with the test switch? If they do are any lit in the start position or the run position? With the wiring correct a lit lamp tells you which circuit is at fault. That is what the 5th terminal on the seat relay controls.

 

Verify that only 4 of the 5 ignition switch terminals are used. The R terminal is not used.

 

The only thing common to the headlamps and the voltmeter are the chassis ground and the power supply through the 15 amp fuse.

 

Garry

[boovuc 1,090]

Hi Garry,

 

Yes the tractor will start without ANY of the relays in. I do have all the idiot lights when the test switch is pushed. Now one of the lights on the panel does light ever so dim when the tractor is fired but I can't remember which one. None are lit in the run position.

 

I'll go out and look at this again in dim light and see if I can identify what light does come on during the start. By the way, when I fired it up last night, there was a full 1 to 2 seconds before the starter fires.

That is, I turn the switch to start and the relay clicks then a good second or two before the starter cranked. This is still better than what I had before but it's the first time since Saturday morning that the thing hesitated that long and it makes me wonder if it's heading south again.

 

Thanks,

[boovuc 1,090]

I do have a very dim PTO Clutch light on when I engage the starter. (Short in that circuit). I forgot about that coming on when I was having troubles getting it to fire. That circuit is jumped so I almost have to have a bare wire somewhere! It is still firing right up now. Still have a 1 to 2 second delay after I hear the relay close.

 

To all the Onan powered 416 owners out there:

 

 Does your tractor have a noticeable delay when starting or does it crank right up as soon as the key moves to the start position?

 

I may be coming to the realization that this puppy needs completely rewired! I accidentally took the day off today! I keep hearing a bunch of trout singing "Catch me if you can" from Herman's Hermits and their rendition is just awful and it must be stopped! 

[gwest_ca-(File Mod) 11,029]

We know that circuit is screwed up because it will start without the relay installed. If you figure how that dark blue circuit is supplying power to the light blue wire going to the solenoid without a relay you likely found your problem.

 

The delay sounds like a circuit with high resistance. Are the ground wires clean and tight and actually grounding?

If you connect a voltmeter between the chassis ground locations and the battery (-) post and get a voltage reading the connection is poor. That would also explain the lights and gauges going out.

 

Garry

[dennist 139]

"Does your tractor have a noticeable delay when starting or does it crank right up as soon as the key moves to the start position?"

No, mine does not have any delay when starting.

[Save Old Iron 1,566]

Let's linger on the word "delay" - almost a mechanical vs electrical sounding word.

 

Consider the delay may be in the mechanics of the Onan starter / bendix.

 

Jump a heavy wire across the starter relay solenoid. If the delay is still there, the delay is in the mechanics of the starter.

 

 

 

 

 

 

 

If no delay there, jump the battery + terminal to the starter relay trigger terminal 

 

 

 

 

 

 

 

any delay now ? yes ?  then maybe the starter relay mechanics / electricals.

 

If no delay there, remove the tan S wire from the ignition switch, jumper it directly to battery + and check for cranking delay. Yes? then there is something in the wiring between the switch and the starter relay.

 

If no delay then try the starter thru the ignition switch - delay there? then maybe the mechanics of the ignition switch ?

 

 

Otherwise Boo, I think Gary has you on the right path. Wire by wire tracing from the ignition switch to the starter solenoid. Trying to resolve this by "the symptoms" may just turn out to be a prolonged exercise in frustration.

 

Pay particular attention to any obvious additions someone may have made into the wiring to pick up a convenient "hot wire" for some other past electrical addition.Don't stop if you find something obvious - there may be more than one wiring fault causing this aberration. 

 

 

The last thought for today is how the headlights and voltmeter fail. Either the grounds to both devices are being interrupted by the insertion of the relay or the relay is inserting its coil resistance into the accessory circuit after the ignition switch. Most of the battery voltage will be dropped across the relay coil with little left to operate the voltmeter or power the headlights, so they will appear dead. Someone may have the power to the voltmeter and headlights wired off one of the relay sockets. Check to make sure the ACC wire off the back of the ignition switch goes directly to the pink wires on the voltmeter / headlight circuit.

 

Make sure the headlight ground wires go DIRECTLY TO A CHASSIS GROUND - not thru hood hinges, etc.

 

That's it for me this morning. Off to bed to recoup from jet lag.

 

 

 

 

 

And for those who demand entertainment instead of education from forum posts

 

I respectfully submit this .......

 

Edited May 10, 2014 by Save Old Iron

[boovuc 1,090]

Ok! I am armed and extremely dangerous with the suggestions I now have. Grass mowed? Check! Fishing? Check! Wood cut for camp? Check! Mothers Day gifts? CRAP!

 

Thank you guys for the probable causes and the clues to chasing this down. I'll make some time this weekend to look into that circuit and get my Fluke out! 

[boovuc 1,090]

Have tried suggestions above and I now know I have a wire harness issue. Just don't know where? It comes and goes. The other day I could use the lights with the relay in. I then shook the crap out of the tractor and off went the lights! I tired to do it again repeatedly so I could wiggle a little wiring at a time but now the light circuit is always poofing on switch contact. The fuses are good and the fuse wiring I did looks good. This is something in the harness somewhere. Most likely something going back to the safety switches and I'm leaning on the Seat switch wiring.

 

Used the VOM on the circuit while rocking the machine and the VOM resistance fluctuates quite a bit. Never to open though.

[Save Old Iron 1,566]

well, going postal on the tractor is a "type" of troubleshooting and as I said before, there is no right spot to start in your diagnosing your case. If headlights don't work then regroup your effort to get the headlights wired properly and working properly. The circuit tracing shoudl be simple. I would throw in an extra wire to chassis ground from the headlight lamp ground terminals. Don't depend on the hood hinge for ground.

 

The headlight circuit wiring should be a straight shot from the ignition switch to headlight switch to lamps - no tap ins, no detours through other wires in the harness. Once you have that circuit nailed down, then maybe, just maybe, other overlooked connections and add ins may show up and lead to the "big one".

 

Fix one issue at a time, even if they one you address first isn't the "big one".

[boovuc 1,090]

OK. I finally found a "fix" the PO did that isn't factory wiring and I can go from there. While I was putting a new belt on it, I was able to see the very bottom Molex plug from all angles. The original PO(s) had cut a red wire going into this plug and completely bypassed it. I also see two other wires that are barely holding on for dear life. I'm taking off both sides of this tractor and starting my tracing tonight. Since tackling the fuse block, the thing is starting right up each and every time now. No hesitation. The lights are also good now. It's just the idea of it running without the starter relay in place that makes me want to make it right again.

[Save Old Iron 1,566]

when you look, you see

 

go boo go

[boovuc 1,090]

I lied about tracing this last night! Streams are a little cloudy so the trout were calling me.......again! 

This weekend.........maybe!  Besides, my knees are getting sore! Damn good thing I'm not Catholic despite my Italian heritage or they would kick me out of church! I'm beginning to feel my late 50's inevitable aging! 

[km3h 543]

Catholics don't kneel as much as they use to.