Small Engine Problems? Ask an Engine Mechanic for Answers ASAP
Thanks for requesting me!
To obtain a service manual for this set, you will need to get one directly from Generac at 1 - 8 0 0 - 4 3 6 - 3 7 2 2
To check on the spark situation, you will need to get to the coil pack.
On the pack is a wire numbered 15R.
Disconnect the connector from the coil pack.
Test wire 15R for 12V while pressing the start switch. If you have no 12V, the control board is bad.
If you have 12V, the coil pack will be bad.
11.7V is close enough.
You can do a rough test with an ohmmeter. (If I can remember this for sure).
Unplug the connector.
Set your meter to ohms.
Connect one lead to the terminal for the 15R wire.
Alternately connect the other lead to the other 2 terminals.
As best as I recall, these readings should be less than 5 ohms.
I do not have it.
I would have to call Generac on Monday.
I've got a part number for you.
It is 0G02070111.
The only letter is the 'G' - the rest are numbers.
Generac says this lists for $218.70
The 5-7 ohms should not be a problem.
The 12 plus volts is a problem. There should be no voltage on wire 15R when the set is not running or cranking.
If this wire is always hot, it means your engine control board is bad, or the wire is shorted to a hot wire somewhere between the board and the coil.
Yes, the wire will also be marked at the board.
On the 23-pin connector, it will be pin number 14.
I have no idea how much the board would cost, but it is part number 0G1303D
The pins are not marked, but it should be the 14th wire from the end.
There is only one wire 15R in this plug. It is the one that goes to the coil pack.
No problem, my friend.
It would seem that there is a relay stuck on the board.
Very strange, indeed.
The only thing I could come up with off the top of my head now are that either the cam sensor or magnetic pickup may be shorted out, causing the board to continue to send 12V to the coil pack constantly. I have honestly never seen this happen, and am not sure.
I will have to get with Generac on Monday to get the proper test procedures.
As far as the board, I do not know anyone looking for one. Sorry.
There should be 3 connectors on the board - a 23-pin connector, a 14-pin connector and a 6-pin connector.
If you are checking pin 14 on the 14-pin connector, this is a ground.
Wire 15R to the coil should go to pin 14 of the 23-pin connector.
The wire 14A at pin 3 of the 14-pin connector is for the run relay.
If you unplug the relay and look at the bottom of it, there are 5 pins. They are numbered 85, 86, 30, 87 and 87A.
Pins 85 and 86 are the control, and pins 30, 87 and 87A are the power supply/feed.
With the relay out, if you test the wires themselves (not the relay), you should find that wire 15 (went to pin 87) should have 12V when the switch is in Auto or Manual.
Wire 15A (went to pin 86) should have power when the switch is in Auto or Manual.
Wires 14 and 14A should not have power at all with the relay unplugged.
The way the relay works is that with no power applied, pins 30 and 87A are connected internally.
When control power is applied, pins 30 and 87 are connected internally.
Wires 85 and 86 are the control. One will be hot, and the other ground.
I'll be heading on to bed here in a few, but am going to try to be back on tomorrow.
On the relay, wires 14A and 15A are the control wires. One of them is a ground, and the other is the control power.
Wire 15 is a power wire on all Generac sets, and wire 14 is always the power supply for the fuel and choke circuits.
I am not 100% clear on how this relay works in relation to this board, since neither seem to go to ground.
I will have to ask Generac when I call tomorrow.
Could you please clarify for me?
Earlier you said wire 14 and 14A had power with the relay unplugged. They should not.
Did you mean to say they had NO power with the relay unplugged?
They should have power with the relay installed.
Ahhhhh. What a difference a single word can make......
Withe the rest of the checks you did, it says the relay is working correctly. Wire 15 is the power input to the relay, and wire 15A is the output. 15A should not have power in 'Off', but should in 'Auto' and 'Manual', which it does.
This goes back to either the cam sensor or magnetic pickup telling the board to keep the coil pack energized all the time.
I will let you know tomorrow what Generac has to say.
I wish they had to work on Sundays like I do........
This is rather fascinating to me, also!
I love being able to help people, and I love working on gensets - they are almost as important to me as my own family.
It is very satisfying to be able to help someone repair their genset, when sometimes all I have to work with is a schematic. One time, I did not even have that - all I had was 2 photos the customer posted!
Saving a customer hundreds, and a couple of times over a thousand, dollars is great.
But I have been working on these for quite some time, and have a fairly decent grasp of how they work.
If you feel my services are worth it, you will have the opportunity to increase your remuneration when we are done.
You enjoy yours, too.
I hope it is warmer where you live than it is here.
Damn. Wanna trade houses?
It's only about 65 here in KY.
Freezing my butt off.
Ok, my friend.
I talked to Generac, and he concurred that the issue is likely to be contained in either the magnetic pickup or the cam sensor.
Both sensors send a signal to the control board to turn the power on and off to the coil.
To test the magnetic pickup, find the small black wire #0 and the small red wire #79. Connect your meter across these 2 wires (leave them connected) and test for voltage. You should get pulses of 1 to 1-1/2 V as the engine is cranking. I am not sure if it is AC or DC, but would suspect AC.
If you are not getting these pulses, the mag is bad.
If you are getting the pulses, check both wires for continuity between the mag and the board. They go to pins 9 and 10 of the 23 pin connector. Make sure neither wire is broken.
There is no actual test for the cam sensor. All you can do is test the wires for continuity to the board. The wires are 0, 194 and 402. All three go to the 23-pin connector. 0 goes to pin 16, 194 goes to pin 7, and 402 goes to pin 17.
Make sure none of the wires are broken.
If the mag, mag wires, and cam sensor wires all test good, the cam sensor needs to be replaced.
The key here is that the 14VAC is at rated speed - not cranking speed.
At cranking speed, the voltage will be much less.
My guy at Generac said it should read at least 1 to 1-1/2V. If you are only getting 0.4, my guess is that the mag is to weak to produce enough current to operate the relay on the board.
I honestly can't say for sure whether it is good or bad, but it sounds bad to me.
One thing you might try. See if you can adjust your mag in just a little to increase the voltage.
Just be careful that you do not get it in so far that it hits the flywheel.
The 12V should not be there when the switch is 'Off'. Shutting the switch off turns off the board.
If this were my set, and adjusting the mag does not help - or can not be done if it is already too close to the flywheel - I would first replace the mag and see what happens.
This magnetic pickup is a Hall-Effect switch. A lot of marine engines use them, and they are really bad about going out.
I'm really sorry there is not a more comprehensive test for it.
And the guy at Generac also told me there is no service manual for this set, so I am also at their mercy and recommendations in regards XXXXX XXXXX things.
Let me know if you can adjust the mag, and what you wish to do next.
Please keep me in the loop.
As far as a recommendation, I am not sure I can make one.
Everyone has different needs and wants, and also has different financial statuses.
I am not going to lie - I love my Onan's. But the drawback to them is the cost - they are expensive.
As far as standby units, Generac dominates the market. They are very economical units.
Generac actually has a very good service and support structure - I have never had any problems with them on that end at all.
A lesser known name (as far as gensets go), is Briggs and Stratton. They make a very good set, also.
I have heard quite a few good things about B&S, but have very limited experience with them.
And then there is Kohler. They make a very sturdy set, but troubleshooting them is very difficult, and their support system leaves a lot to be desired.
If I were in the market, my first choice would be Onan, if I could afford it, then I'd look at B&S, then Generac, then Kohler.
I had never thought about it, but I bet rust is a bad problem there, with no way to get away from the salty air.
Keep me posted.
Yes, this voltage will be fine. Resistance of a coil of wire is very temperature dependent, and voltage is directly influenced by resistance.
You should be good to go now.
Any time you need help with anything in the future, just ask and we will Just Answer!