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Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 14993
Experience:  Certified on Onan and Generac generators
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Hi, Hank My generator cranks but wont run. There are no

This answer was rated:

Hi, Hank:
My generator cranks but won't run. There are no spark at the spark plugs. Also where can I find the Diagnostic and Repair Manual for Centurion (Generac) 1.6L 25kW (Model 5326-1) Thanks


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.


Customer: replied 6 years ago.
Hi, Hank:
I have 11.7V at 15R. Is there anyway I can test coil pack? Or this fully confirms that it is defective? thanks

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.





Customer: replied 6 years ago.
Okay, I will check that. For the life of me, I can find the part number the coil pack on owners manual. Can you help?

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


Hank F. and 3 other Small Engine Specialists are ready to help you
Customer: replied 6 years ago.
Hi, Hank: I check the ohms on the coil pack between the terminals. The reading fluctuates between 5 and 7 ohms. Another thing I noticed was the wire 15R has 12 plus volt when the engine is not cranked. It has 11.7 volt when being cranked. Is this normal?

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.


Customer: replied 6 years ago.
Hi, Hank: I should be able to find the 15R at the board right? Then I could check the pin right at the board to isolate if it is the board or the something in between. I hope it is something in to board could cost me hundreds of dollars!
Thank you again for taking the time answer my questions. I am so glad I found you and this website!

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


Customer: replied 6 years ago.
Thank for part number Hank!
I didn't see pin number 14 but there is the same 15R—the same wire that goes to the coil pack...can you confirm?

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.




Customer: replied 6 years ago.
Okay I got it. You are right the pins were not marked. I found the wire was labeled.I will do the test tomorrow and will let you know. Thank you for staying up late Hank! Got run to another task!

No problem, my friend.


Customer: replied 6 years ago.
Hi, Hank:
The 12 V is coming from the board. So the board is faulty!

It would seem that there is a relay stuck on the board.


Customer: replied 6 years ago.
Hi, Hank:
You are probably correct. Something is causing the relay to get stuck then. I purchased a brand new board $367.00! put it in and give me the same voltage reading! The dealer told me that the board is non-returnable...

Any idea what to check next? If you know any would buy this card let me too...


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.


Customer: replied 6 years ago.
Hi, Hank:
Thanks for checking at my reply on the weekend! Strange indeed! I also purchased the Diagnostic and Repair manual. I haven't seen any test procedure for for cam sensor in the manual. Please let me know what are the test procedures. I checked the Run Relay the coil and it is okay. But I have feeling something is preventing it from getting the voltage to energize it. I also don't get any voltage on the terminal 14 at the TB1. However there are voltage on 14A (coming out of the board. I don't know if any of these make any sense to you? Thanks again for help!

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.


Customer: replied 6 years ago.
Thank you for the clarification.
Okay this is the 14A of the 14-in connector. Okay, it is good thing there are power there. How do I check if the contact of this run relay is closing the and power is being transfer to all the necessary items? In another word which wire feeds the power to the contacts of the run relay and which one takes it out?

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.


Customer: replied 6 years ago.
I'll test them out and let you know.


I'll be heading on to bed here in a few, but am going to try to be back on tomorrow.


Customer: replied 6 years ago.
Good morning, Hank:

Okay I did few tests and below are the results of my finding:

Test: 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.
Result: I have 13.3V in all Auto, Off and Manual position of the switch.

Test: Wire 15A (went to pin 86) should have power when the switch is in Auto or Manual.
Result: I have 13.2V in Auto and Manual postion. No voltage in Off position

Test: Wires 14 and 14A should not have power at all with the relay unplugged.
1. This is correct, there are power at these two points
2. I get 11.9V at 14A when the engines is cranked with the relay back in place
3. But there is no power at 14 when the engine cranks

I swapped the two relays but there are no changes. Any thoughts?

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.


Customer: replied 6 years ago.
Hi, Hank: Thank you for checking with Generac tomorrow!

I did further investigation and found the wire 14A at the Run Relay does have power when the relay is plugged-in (even without being cranked). So it is ground wire—I think the board controls it—when it should be grounded in order to energize the coil—to complete the circuit. I traced the 14A and it appears to go to the 14-pin connector.

It leads to the card again. I wonder if something external is causing the card not to ground 14A in order to energize the Run relay? Is there something else between the relay and the board?

The strange thing is that the new card don't work either. I am assuming that the engine need to be running in order to calibrate the card with Magnetic Pickup and the calibration is not the reason why the new card is not working.


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.


Edited by Hank F. on 10/3/2010 at 8:38 PM EST
Customer: replied 6 years ago.
Sorry about the confusion. Yes, I meant to say that they have no power with the relay unplugged.

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........



Edited by Hank F. on 10/3/2010 at 8:44 PM EST
Customer: replied 6 years ago.
Thank you so much Hank! Very impressive how you do this remotely without looking at the machine! Looking forward to hear from you tomorrow—hopefully we can resolve this issue!

I am wondering if will allow me increase my tip to you :-) I want to tip you more once we fix my generator. I really appreciate your help Hank!

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.


Customer: replied 6 years ago.
To have someone like it is really helpful to us who live in a remote area. I will check in tomorrow morning. Enjoy the rest of your weekend!
Thanks again.

You enjoy yours, too.

I hope it is warmer where you live than it is here.


Customer: replied 6 years ago.
Beautiful day here. Temperature is about 79º perfect as it can get in a paradise :-)

Damn. Wanna trade houses?

It's only about 65 here in KY.

Freezing my butt off.


Customer: replied 6 years ago.
Not sure if I can survive that temperature. We begin to complaint it get down 71 in the winter! We are so spoiled here—island of Kauai, Hawaii.

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.


Customer: replied 6 years ago.
Hi, Hank:
Okay I did all the test and here are the findings.

1. Since I don't have the breakout harness to go the Mag sensor, I just pocked in a fine bare wire in the conector holes. The reading I got was 0.4 V AC, does this means the Mag Sensor is bad?

2. Checked continuity on the Mag sensor wires and they all are good.

3. Checked the continuity on the Cam sensor wires and they all are good.

Additional information about 15R wire to the coil pack:
Don't know if this make any difference, the constant power—12V at this wire only happens when the switch is set to Auto or Manual postion. No power if the switch is set to Off position.

Additional question regarding the Mag sensor test:
The new board that I purchase came with Generac's Product Info. Bulletin PIB07-25-S
That give the following information below but the voltage indicated was different that you suggest above. The indicates 14 VAC. See the text below from the bulletin.

Thanks. XXXXX for Installation of the Magnetic Pick-up

1. Turn the AUTO/OFF/MANUAL switch to the OFF position.
2. Using a flashlight, verify a flywheel tooth is directly below the magnetic pick up hole.
3. Screw the magnetic pick-up down lightly until it contacts the top of the flywheel tooth.
4. Back the magnetic pick-up out one (1) full turn.

NOTE: Voltage may vary depending on the
engine type.

5. Connect the (PIN#OG41800SRV) breakout harness to the magnetic pick-up in line with the engine control harness.
6. Turn the AUTO/OFF/MANUAL switch to the MANUAL position to verify the unit starts.
• If the unit starts, proceed to step 7.
• If the unit does not start, inspect dip switches and repeat steps 1 through 6.

Magnetic pick-up adjustment for OG3958 Control board
7. Turn the multi meter to read AlC Voltage and insert leads into the breakout hamess.
8. Turn the AUTO/OFF/MANUAL switch to the manual position to start the unit.
9. Adjust magnetic pick-up to 14 VAC +/- .5 volts @ rated speed.
10. Tighten down the magnetic pick-up lock nut to prevent the magnetic pick-up from coming loose during running operations. Use blue 232 locktite, if available.

NOTE: Reference PIB07-17-S for specific generator magnetic pick-up voltages using (PIN OD2244M) for speed reference.

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.


Edited by Hank F. on 10/5/2010 at 4:15 AM EST
Customer: replied 6 years ago.
Hi, Hanks:
There is may 1/8th of an inch space left between the Mag sensor and flywheel. So I don't think I can adjust it any more without damaging. I can see there are no other way to go further with the trouble shooting without changing the sensor. I have order them from mainland and will take several days before it reaches to Hawaii. I will let you know once I put in the new sensor.

To bad that Generac do not have service manual for it!

Hank, in your opinion if I were to buy another unit in the future (20 to 30 KW) which would you recommend? Servicing, repair manuals are available and something a mechanic would love to work with!

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.



Edited by Hank F. on 10/6/2010 at 4:00 AM EST
Customer: replied 6 years ago.
Thanks for the thoughts Hank!
I call Generac's main number—1800(NNN) NNN-NNNN either I got someone with bad mode or they are not very helpful to end users. The person on the customer support keep asking me to call the dealer with zero technical help. The dealers that I found in Hawaii are not very helpful—since I purchased the unit from Grainger. I was kind of disappointed. I am glad I found you!!

I am happy with Generac first for the price...second for almost three years I never had a single problem.
I will look into Onan for future purchases six or seven years down the road. Things rust very quickly here...

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.



Customer: replied 6 years ago.
Yes, you're right.

Okay the parts were shipped from California. It should be here in about 3 days. You'll probably hear from during the weekend or Monday with an update. Aloha!


Keep me posted.


Customer: replied 6 years ago.
Aloha, Hank:

Good news! The Magnetic PU was the defective part. I replaced it the the Generator's engine was running! Thank yo so much for all your help!!

I did the calibration based on the document that came with the part—bulletin # XXXXX

The parts list on my unit listed the board's part number as 0G1303 and the bulletin indicated that the VAC for this card is 1VAC ±0.05 VAC.
I am getting 0.929VAC when I measured the MPU voltage. It is little less than the tolerance specified. Is this okay? The gap is already pretty close between the MPU and the flywheel. I tighten it until it touched the flywheel tooth than backed one turn.
Please let me know. Thanks

Great news!


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!


Hank F. and 3 other Small Engine Specialists are ready to help you