Coast Resorts Open Roads Forum: I believe my coil is bad on my Onan 4BGE generator
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 > I believe my coil is bad on my Onan 4BGE generator

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maillemaker

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Posted: 04/08/18 02:51pm Link  |  Quote  |  Print  |  Notify Moderator

Hi all:

Generator is Onan 4BGEFA26101A

Which I take to be a 4BGE, Spec A, Onan Generator.

The generator cranks, but will not start.

I used a spark tester light, which goes between the spark plug and the boot, to determine that there is no spark to the outward-facing spark plug. I did not bother to check the inward-facing plug once I determined there was no spark on the outward plug. I tested the plug light on the RV engine itself and the light works.

I removed the coil from the genset, and performed the following resistance tests on the primary and secondary coils:

[image]

It looks like the primary coil is good, measuring 3.6 Ohms. It should measure between 3.87 and 4.73 Ohms. It is a little under but this is probably OK.

[image]

I believe the secondary coil is bad, measuring only 17.4 K Ohms. It should measure between 34.0 and 41.6 K Ohms. This is way out of spec, and indicates a shorted coil according to the manual.

[image]

Does everyone agree I'm reading my Ohm meter correctly? I'm not an electrical person.

The coil is marked 166-0761:

[image]
[image]

This coil with built-in mounting brackets does not appear to be available anymore. I see replacements, with separate bracket, available on ebay.

Some are listed as HE166-0761. What is the difference between HE166-0671 and 166-0671?

Here is a non-HE one for $86:

https://www.ebay.com/itm/New-Ignition-Coil-For-Onan-Generator-Welder-Factory-541-0522-Replaces-166-0761/173128934985

And here is an HE one for $60:

https://www.ebay.com/itm/Replaces-Onan-Ignition-Coil-P-Model-541-0522-166-0820-HE166-0761-HE541-0522/173225446794

Thanks,
Steve


1990 Winnebago Warrior. "She may not look like much but she's got it where it counts!"



Kpackpackkelley

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Posted: 04/08/18 03:18pm Link  |  Quote  |  Print  |  Notify Moderator

I don’t know the difference in the two coils you show but you did clean the corrosion out of the female sockets on the coil ? That gen will run on one cylinder so I would check the other plug wire too. SR Sales has a lot of old onan parts call them. https://www.srsoemparts.com
You’ll have to call them tomorrow. Go here and post your problem too.
https://www.smokstak.com/forum/forumdisplay.php?f=1

Kpackpackkelley

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Posted: 04/08/18 04:31pm Link  |  Quote  |  Print  |  Notify Moderator

Also go here he can tell you about those two coils also. https://www.onanparts.com

Kpackpackkelley

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Posted: 04/08/18 04:53pm Link  |  Quote  |  Print  |  Notify Moderator

Looked in the parts manual and it shows 166-0772 it is available.

maillemaker

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Posted: 04/08/18 05:10pm Link  |  Quote  |  Print  |  Notify Moderator

Quote:

Looked in the parts manual and it shows 166-0772 it is available.


Do you have a link to a source?

Also, I just discovered that the genset is actually a 4BGEF826101G. This is from the tag on the genset, which differs from the RV owner's manual summary page!

This is good news, as it means that I have electronic rather than points-based ignition.

Steve

maillemaker

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Posted: 04/08/18 05:20pm Link  |  Quote  |  Print  |  Notify Moderator

OK, the coil is not bad. Now that I know I have a Spec G genset, when I read the section for Spec G gensets it says:

[image]

So, my primary coil is just a hair low, and probably fine, and my secondary coil is also just barely a hair low. So my coil is probably within specs for a Spec G genset.

So now I have to figure out why I'm not getting any spark.

Steve

Kpackpackkelley

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Posted: 04/08/18 06:29pm Link  |  Quote  |  Print  |  Notify Moderator

Ok 166-0761 would be for the spec g I was looking at spec a.

midnightsadie

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Posted: 04/08/18 06:48pm Link  |  Quote  |  Print  |  Notify Moderator

possible its a fuse?

maillemaker

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Posted: 04/08/18 06:58pm Link  |  Quote  |  Print  |  Notify Moderator

Quote:

possible its a fuse?


The only fuse I am aware of is the one on the control board. It is fine.

I believe the control board decides whether or not to allow the generator to start by controlling the ignition and fuel circuits. Next weekend I will follow the service manual debug instructions for checking the control board and voltage regulator.

Steve

Kpackpackkelley

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Posted: 04/08/18 07:03pm Link  |  Quote  |  Print  |  Notify Moderator

Read up in the service manual about the control module arms they can break off. Which manual are you looking at so I can look it up. Look in 965-0528 page 6-10 at the ignition module.

* This post was edited 04/08/18 07:13pm by Kpackpackkelley *

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