# Generator help please?



## bbqjoe (Feb 10, 2017)

Onan generator. Model# 4BGEFAZ6100P. Sat for 10 years. Ran when put away.
Mice got to the wiring.
I went through the wiring harnesses and repaired each wire one by one so as not to mix anything up.

I found some burnt and lifted traces on the control board.
No telling why, but quite possibly due to some shorts from the mice.
Went ahead and replaced the board, the fuel pump, filters, oil etc.

This is out of an RV, and has been stand alone forever.

The engine cranks, maybe not getting fuel to the carb, but that's beside the point for right now, I think.
I pulled the plug and did a spark test.

The start switch is new with the board, and comes mounted on it.
The switch is a two or three way rocker, depending on how you see it.
One direction is start, after start it rests in the middle, until rocked the other direction to stop.

There is no spark when cranking, until I let off the start switch, then I see a couple of sparks as the engine quits spinning.

Argh!!!

I very vaguely remember putting a jumper in the remote start coupler for some reason, although I'm not 100% on that.

Any ideas, work arounds or things I might try?

Thanks,


Joe


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## Caribou (Aug 18, 2012)

The switch could be bad. I know it is new but new things sometimes come broken so it is worth considering.

It sounds as if it might be a lose or corroded connection. It gets spark when it is in the run position but not the start position so is there a different wire for the spark when starting?

Is there a way to jump the starter while the switch is in the run position?


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## Justaguy987 (Mar 2, 2013)

Caribou said:


> .....It gets spark when it is in the run position but not the start position so is there a different wire for the spark when starting?


I have no idea about a generator, but I know some older cars were this way. While starting, they had full batter voltage going to the coil. When the key was in the run position, the power to the coil went through a resistor first to lower the voltage. Might be the same type of thing.


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## Viking (Mar 16, 2009)

Justaguy987 said:


> I have no idea about a generator, but I know some older cars were this way. While starting, they had full batter voltage going to the coil. When the key was in the run position, the power to the coil went through a resistor first to lower the voltage. Might be the same type of thing.


That was a resistor bypass, I'm not so sure it's done on Onan engines, because that goes back to maybe the early 1970's. After that more engines were using electronic ignition that didn't require a resistor to the coil. What his problem sounds like is what Caribou mentioned, but it could be on of those bayonet plugs that has lost it's spring tension and it's plugged in but not making a solid connection, I've seen that happen far too often and when it happens the connectors become corroded to the point of allowing just a little electricity to pass, often intermittently, enough to give a few sparks, like when the start button is let off. I've cleaned connection surfaces and tightened those plug springs using needle nose plyers and sometimes it works good, other times I've just had to replace the plugs. I've seen this problem with RV heater controls, starter solenoid connections and even when I did custodial/maintenance work at a school district, working on large electrical heat systems and those bayonet plugs were made of nickel, it's just that where they connected was 240 VAC and about 4500 watts, very hot, to where it would take the tension out of the plugs and then they would fry. One other thing is that they don't do well having the weight of wires unsupported.


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## bbqjoe (Feb 10, 2017)

Thanks for the replies so far.

I don't think it's the switch itself. The odds are too high IMO. The gen is acting the same as it did before I replaced the CB.

Spinning the starter may be a plan I will try tomorrow.


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## Caribou (Aug 18, 2012)

bbqjoe said:


> Thanks for the replies so far.
> 
> I don't think it's the switch itself. The odds are too high IMO. The gen is acting the same as it did before I replaced the CB.
> 
> Spinning the starter may be a plan I will try tomorrow.


I doubt it is the switch myself and it wouldn't be the first thing I checked but I would keep kit at the bottom of the list.

You didn't mention the battery. I've had old batteries and bad battery connections that wouldn't provide enough power for everything when the starter was turning.


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## bbqjoe (Feb 10, 2017)

Caribou said:


> I doubt it is the switch myself and it wouldn't be the first thing I checked but I would keep kit at the bottom of the list.
> 
> You didn't mention the battery. I've had old batteries and bad battery connections that wouldn't provide enough power for everything when the starter was turning.


Brand new Interstate. Fully topped up. Heavy jumper cables for connections.


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## bbqjoe (Feb 10, 2017)

AdmiralD7S said:


> Does it have enough oil? When I put a new engine on my rototiller, it came with some oil in it. Since it doesn't have a dipstick, I assumed they filled it high enough. I couldn't get it to run, and I traced it to no spark. Turns out there's an oil sensor/switch in the engine that cuts spark if oil is low. Your generator might be similar.


Just replaced the oil, it's full.
Tried the engine with and without sensor hooked up.

Again, there's spark, but only when the start button is released.
Maybe 2 sparks.


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## azrancher (Jan 30, 2014)

It's got 3 relays that I believe are separate from the control board.
K1 is the starter solenoid
K2 is the crank ignition which energizes K1 and provides ignition power.
K3 is the run ignition which provides ignition power thru a resistor.

Sounds like the relay, or wire from K2 to the ignition is not working.

Many hard to read schematics of the circuit out there...

I had one in a huge horse trailer that my wife couldn't park, pretty neat operation from inside the quarters, press down on the switch (off) and the priming pump runs, after X time the light goes on, reverse the rocker switch position and it cranks and starts... remotely, center position is run, which is it's default, non spring loaded position.

*Rancher*


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## bbqjoe (Feb 10, 2017)

azrancher said:


> It's got 3 relays that I believe are separate from the control board.
> K1 is the starter solenoid
> K2 is the crank ignition which energizes K1 and provides ignition power.
> K3 is the run ignition which provides ignition power thru a resistor.
> ...


Damn, I don't know my K1 from my k3. You don't got a pic do you?


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## azrancher (Jan 30, 2014)

To determine if my theory is correct, use voltmeter, alligator clips, unless you have 3 hands or a helper, check voltage on the + terminal of the coil, see if there is 12 volts when cranking, or just hot wire it and see if it starts.

*Rancher*


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## azrancher (Jan 30, 2014)

OK Pics, not sure if they are for you model, but the start and run circuits should be all the same.










The Starting circuit...

Pressing the "START" switch (S3 or the Remote Switch) will power the starter relay [K1] by applying a ground through the "HOLD RELAY" contact K2a (normally closed contact)

When the "Start" relay [K1] is energized it activates:

(a) Starter solenoid and starter motor [B1]
(b) Electric choke solenoid [E1]
(c) "Run Relay" [K3] thru CR5 and R2

The "Run Relay" contact [K3] (normally open) applies power to the following:

(a) Fuel pump [E2]
(b) Fuel solenoid [K4]
(c) Ignition coil [T1]

Resulting action: Engine starts and runs










The running circuit...

The output (AC voltage) of the alternator [G1] increases as the engine speed increases. This AC voltage is converted to DC voltage by Diode [CR1], Resistor [R1], and Capacitor [C1] and is applied to the "Hold Relay" coil [K2].

The "Hold Relay" [K2] is energized when the applied voltage reaches 10 to 11 volts DC (typical). One contact of [K2} opens to disable the start circuit ([K2a] - See Fig. 1) and the second contact [K2b] closes to apply power to the following:

(a) "Run Relay" coil [K3]
(b) Remote control panel
(c) The low oil pressure (LOP) circuit.

What this all says is that when the engine starts it switches out the start circuit & the starter and lets the engine run.

Physical location of the relays, heck I don't know, follow the wires back from the coil, the fuel pump, etc.

*Rancher*


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## azrancher (Jan 30, 2014)

*More Information*

EMERGENCY START / STOP PROCEDURE
Bypass circuit board (all functions except fuse) as follows:

! Jumper terminal 9 to 5 (fused power) - This will energize the fuel pump, fuel solenoid and ignition coil
! Press the "Start Switch" [S3] or temporarily jumper terminal 1 to 7 - This will engage the starter. Remove jumper as soon as the engine starts. Note: Do not press switch or jujper terminal 1 to 7 while engine is running.
! Remove jumper from terminal 9 to 5 for engine stop

CAUTION: This emergency / test operation does not provide starter disconnect or Low Oil Pressure shutdown protection and should not be used without monitoring the motor generator.

*And oh by the way, we need a video of it running, or it didn't happen!*

*Rancher*


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## phideaux (Nov 7, 2015)

Excellent example of Prepared Society working at what it was intended to be.

Good info.


Thanks azrancher,




Jim


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## Flight1630 (Jan 4, 2017)

Try adding a capfull of gas right into carb and see if it runs for a couple of seconds. If it does run for a few seconds you might have a pluged fuel line. If it doesn't run then it might be your points not making contact properly.


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## bbqjoe (Feb 10, 2017)

azrancher said:


> *More Information*
> 
> EMERGENCY START / STOP PROCEDURE
> Bypass circuit board (all functions except fuse) as follows:
> ...


I took a lot of classes from the older kids when I was young. It's probably a good thing I missed the one on hot wiring.

Being as there is no distributor, this must be elec ignition.
So by running 12 V to the positive side of the coil is hot wiring?

I'll try your suggestions, and see who's who in the zoo.


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## azrancher (Jan 30, 2014)

Yes on the hot wiring...  kids nowadays how did they ever grow up not knowing how to hot wire a car...

*Rancher*


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## bbqjoe (Feb 10, 2017)

Well...isn't this special????

Inside the whole mess, right on the engine side of the generator, are two Farking *PLASTIC* arms with magnets that excite the ignition module.

A common occurrence: Mice build nest, engine gets turned over, plastic arms get hung up in nest, arms break.

I'm going to have to split this darn thing to replace it.

I wish engineers would stick to driving trains. :surrender::brickwall:


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## azrancher (Jan 30, 2014)

bbqjoe said:


> I wish engineers would stick to driving trains.


That's why we become engineers, so we can blow the whistle 

Wonder why you were getting spark when releasing the start switch?

*Rancher*


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## bbqjoe (Feb 10, 2017)

azrancher said:


> That's why we become engineers, so we can blow the whistle
> 
> Wonder why you were getting spark when releasing the start switch?
> 
> *Rancher*


Hellofa good question. I guess I'll cross that bridge when I get back to it.
But really, I know why, but I just have to ask it out loud.

Why in the blazes would you place the very heart of the whole thing in the middle, then build it out of plastic???

The next challenge will be getting this thing to separate.
I disconnected all the wiring, removed the carb, removed three large bolts, and thought what the hell, this is going too easy, so I just sheared the fourth one for laughs.

I gave it a few taps, and it moved enough to slip a hair between the two, but I'm afraid there may be something further yet I don't know.


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## bbqjoe (Feb 10, 2017)

I have a new plan.
I read the service manual to separate, and it looks like I might have to go to some school somewhere to be able to do this.

I'm going to mount the ignition sensor above the fan in the rear, then attach magnets at TDC.

If that doesn't work, it can sit for another ten years.


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## bbqjoe (Feb 10, 2017)

Here we go. I just have to figure out why it works best running a hot wire to the coil. I'm guessing it's a bad connection somewhere.


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## bbqjoe (Feb 10, 2017)

Update.


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