MEP-803A Gauge Needle Tick (Solved)

[Tinstar]

We have a major (for us) snow/ice storm headed for us and fired up my generators to make sure everything is ready and let them run for 1 hour.
No loads attached (I know!), just a battery top off and hot oil check.

The 803 stared right up as always and zero issues.
About 30-40 minutes into the run, I noticed the Fuel and Oil Pressure gauge needles were ticking or snapping to the right very fast about 1/8” and then back to normal every 5 seconds.

No other gauges were doing this and this set has never done this before since I’ve owned it. I’ve put almost 20 hours of run time on it since purchase.
No changes in engine sound or tone or any additional noises.
The gauges read correctly, as verified by the secondary oil pressure gauge and fuel tank level visually checked.
No wires chewed or anything out of the ordinary.

Shut down generator and restarted after 15 second pause.
Tick/surge went away and rest of test run was normal.
Generator is on a trailer and not physically hooked up to anything.
It was about 8 feet from another generator running at same time, also not hooked up to anything.

I’ve never heard of this or read anything in the generator forums.
I haven’t a clue what would cause this or if it’s just a quirk with these machines.
TM's were no help and had zero reference to this

Ideas?


EDIT
The outside air temperature was below freezing, about 30, during the time of the run and is the coldest temperature the generator has operated in since my ownership.
Don't know if that matters, just additional info

 

[Ray70]

My first thought would be something with the voltage coming from the alternator ( rapid fluctuation / spikes ) possibly??
I've seen the same thing before, but not sure what causes it.

 

[Ray70]

My 2nd thought is that I wouldn't be overly concerned about it!

 

[Tinstar]

Ammeter is rock steady and reading normal, decreasing slowly as unit runs longer and charges up the batteries.

Scratching my head on this one

EDIT
Corrected voltmeter to ammeter

 

[Ray70]

What volt meter? Your 803 doesn't have a DC volt meter unless you added one?

 

[Ray70]

I think you're talking about the ammeter.... that won't tell you anything about DC voltage, it only tells you how much current is flowing into and out of the batteries.

 

[Tinstar]

I think you're talking about the ammeter.... that won't tell you anything about DC voltage, it only tells you how much current is flowing into and out of the batteries.

Correct
I meant ammeter

 

[BeStihl]

The gauges share a ground so maybe make sure the DC ground connection inside the control panel is clean and tight. Sounds like something has a flakey connection for 2 meters to do that at the same time, my opinion.
I personally would also check DC voltage while running with a known good volt meter, just to satisfy my mind that the alternator belt is not slipping or doing something unusual.

Daniel

 

[Tinstar]

I did check voltage after the post this morning and it’s rock steady at 120.5v and 61.5hz.
Looked at the ground for those gauges today and all nice and tight and clean.

After this storm passes, I will start it up again and see if it happens again.
Hopefully generator won’t be needed due to ice.

 

[Guyfang]

I might be able to find the PS article about the meters and bad grounding. It seems that the meter holding bracket gets tightened to much, and the bracket gets bent. The bracket is what provides the ground to the meters.

 

[Ray70]

2 things....
1) We're talking about DC battery charging voltage, not the 120V 61.5 Hz AC voltage.
This can be measured a bunch of places including the Slave Port, the battery wire on the back of the alternator, even the + and - terminals ( labeled I (( ignition )) and - ) on the back of the gage. Only problem is that if there are quick spikes up and down a DMM probably won't detect them very well, you need an analog meter.

2) I never want to disagree with Guy because he has more generator knowledge in his pinky finger than I will ever have in total, but the 803's gages don't ground through the bracket, the 3 engine gages have a ground wire (-), a Positive wire ( i ) and a sense wire.(S) , 1 of the mounting studs has the ground wire double nutted to it but the bracket is actually isolated from the studs with plastic bushings. however.... to Guy's point, a problem with the plastic bushing could be causing some kind of weird anomaly with the ground path,

 

[Tinstar]

I'm on the same page now on DC voltage.
I did not check that but will

Your second point also points out the potential problem.
Both of those gauges, just those, have cracked cases that I have "repaired" with DOW Mil-Spec 3145 sealant.
I'm now wondering if the cold has or is causing the issue to show itself.
Gauges work fine when warmer, but the cold is causing things to shrink a bit and possibly causing the issue.
Maybe the vibration of shutting the unit down and then restarting was enough to make whatever contact point connect again.
This was the first time I ran the machine in cold weather, and the cold possibly affected the gauge housing just enough.

It was 15 degrees this morning with much colder temperatures this weekend.
Saturday the high is 9.

I will open the panel tomorrow and check that.

 

[Guyfang]

Never hesitate to correct me! I am old and in the way!!

 

[BeStihl]

Never hesitate to correct me! I am old and in the way!!

I don’t know about in the way, but old may be a possibility.

 

[Ray70]

In the way....?? don't think so...
Old?? well, older than me, but that's about it!

 

[Summerpaws]

Never hesitate to correct me! I am old and in the way!!

Hey Don. You're the same age as me so, yes, we are old, The way I see it is we provide the base of knowledge that these young'uns build on and modify!

 

[Tinstar]

Well……..
Found the issue I think.

The fuel gauge housing is cracked a LOT more than it was before.
Ground seems ok but bracket is a bit loose and cannot obviously tighten it up more.
All wire connections are tight and clean.
I did not run unit.

Storm hits tomorrow so out of time for a quick fix since I don’t have a spare and the adhesive wouldn’t set up in time today.
I had in my head that I already fixed that but will blame that on old age.

 

[Light in the Dark]

Well at least its just an operator gauge, and doesn't impact machine performance or low fuel level on/off functionality. Just fill the pig and check on it every 6 hours under use and put a set of eyes on the fuel level through the fill neck.

 

[Tinstar]

That’s the plan.
Hopefully the ice stays south of us.

 

[Ray70]

Quick tip!
I use JB Weld quick epoxy for virtually everything lately.
It's the yellow and black cap one, not the Red and Black.
It sets up in like 15 minutes and sticks to pretty much everything except nylon.
it even works on urethane automotive bumper covers.
strong, quick dry and slightly flexible to resist cracking and delaminating!
It will glue that gage shut in time for lunch today.