Board index Flathead Power-Technical Questions, Answers, and Suggestions Twin Cams Electrical problem...2000 FLHTCU/I

Electrical problem...2000 FLHTCU/I

Moderators: Curt!, Pa

Post Sun Apr 29, 2007 4:33 am

Posts: 976
Location: Markt Einersheim, Germany

Hope to get this figured out....

On my E-glide, I got her cleaned up for the upcoming season of riding..

Hand Washed, waxed got her all prettied up......was going for a cruise, about 15 miles into the wanttobe ride, I stopped for gas. had 1/2 tank but what the heck...

After fill up.......about 2 miles down the road......when problem was noticed...

1, gas gauge bobbed bewteen full 1/2 tank...1/4 tank..full...empty...full...

2 Same time as gas gauge acting up....the oil pressure was pegged at 60...then 32...then 60 then zero then 60 then back to around 32....

What is common bewteen the two??

And in which wiring bundle do the siginals from the gauges go back thru to the sensors?

I am going to try and locate a wiring schematic that I got laying around here somewhere......(but ain't sure where I put it).

And on the oil pressure switch.....any paticuar Ohms reading I shoud be getting from it?


George in Germany

Post Sun Apr 29, 2007 5:44 am
Pa Site Admin

Posts: 5774
Location: Ohio USA

George, I'm not up on that model what so ever, but IMO, your symptoms combination, act like a computer failure to me. Could be an intermittent short too though. Pa

Post Sun Apr 29, 2007 7:54 pm

Posts: 1667
Location: Interlaken, NY USA

George, pretty new for me, but ususally in electronics when 2 or more unrelated things start happening, check your grounds. That's what they usually have in common. I hate to say it, but my limited experience with cars at least, is that usually it's not the computer's fault, it's just trying to deal with lousy signals from the outside, (sensors) world.
good luck
Intern Dick

Post Mon Apr 30, 2007 9:39 am
Pa Site Admin

Posts: 5774
Location: Ohio USA

That makes sense Dick. My dis trust in computers stems from an experience while repairing a Cadillac. It came equiped with an onboard diagnostic center. The diagostic center indicated all the fault codes without the use of an external code reader. The center is basically the same as the external code reader with the exception of it being built right in. I beat my brains in trying to find the failures. The code reader brought up the first fault number. I replaced the sensor for the faulty code. This didn't repair the problem. The onboard reader brought up a new fault code after replacing the sensor. I then replaced the sensor for that code. Still new fault codes apeared. After replacing several different sensors and after many a dollar spent, I began thinking the ecm may be at fault. It was the ecm that was providing the fault codes so my logic was........try a new ecm. I had to weigh the dollar sum too though. If I replaced the ecm and the problem wasn't solved, I would have then spent another hard to come by buck with no positive results. I took the chance and replaced the ecm anyway. End result was, the ecm, all along, was reporting fault codes that didn't exist in the first place. I had replaced several perfectly good sensors for not. I guess I got lucky. All I can say about todays tech is this.... Works awesome when woking well. Makes trouble shooting a hair puller at the very least. :lol: Pa

Post Mon Apr 30, 2007 9:26 pm

Posts: 976
Location: Markt Einersheim, Germany

Took off left saddle bag and fuze holder, seat.

Found corrosion on the 15amp fuze for the instruments... cleaned it up with some corrosion/contact cleaner that I got from the avionics shop...seems to have solved the oil pressure problem...gas gauge is still actin up.......

Today is a Germany holiday so I hope to be able to get the front fairing off and to the back side of the instruments so I can clean all their contacts..

From the schematic that I have their is a shared orange wire between the gas gauge, oil pressure gauge and the tachometer....

I beleive that since the tacho was not acting crazy the problems futher back down the stream before that splice...

I'll let ya know..


Post Tue May 01, 2007 5:48 am

Posts: 1667
Location: Interlaken, NY USA

Good luck George, and don't forget the "smoke" theory on electricity....

Post Tue May 01, 2007 6:40 am

Posts: 7
Location: West Bend Wi
the or. wire is a power feed and should run the lights as well if your not having a problem with a flickering light I would pull the dash and clean the connections at the sending unit first this would be a common place for a poor connection.

Post Tue May 01, 2007 11:59 am

Posts: 1050
Location: Greenbackville, Virginia, USA
George, don't forget those "fat" electrons, they don't fit through corroded connectins very well, at best intermitant. And a bad connection anywhere in the circuit will have you chasing your tail forever. G 8)
P.S. If you think that's bad, you should try my 26 yr old shovelhead. I wound up takinng EVERY wire off and cleaning contacts and re-assemble just to get lights and spark, Turned out to be dash switch (DOUH!).

Post Tue May 01, 2007 8:11 pm

Posts: 976
Location: Markt Einersheim, Germany

Did not pay any attention to lights........

Riding during daytime.......I'll check that too..

Thanks fellas.......

George in Germany

PS.....any way to troubleshoot the fuel sending unit?

Post Wed May 02, 2007 6:54 am

Posts: 7
Location: West Bend Wi
Harley gives ohm specs for the sending unit "full 39.5/27.5 half 118.0/97.0 empty 260.0/240.0" I have found that its easier to hold the unit in position and watch the gauge also take a good look at the unit itself all it is is a simple wiper switch. Clean the external plugs first I personally have never had to replace a sending unit. If you store your scoot for the winter or ride in the rain you will want to use a little di-eletric compond on all the connections you clean, when they corrode they lose the thin protective coating on the pin and as a result they will fail twice as fast. I use a drop on every connector I r and r.
P.S. I have had too replace a gauge or two.... over the years.
Imagination fuels everthing
Fix the problem bye a shovel!!!!!
Pat :lol:

Post Mon Jun 04, 2007 9:13 pm

Posts: 976
Location: Markt Einersheim, Germany


Got her fixed.........

Dirty connections :( , AND....a dead oil sending unit... :(

Oil pressure sending unit was ZERO Ohms........

Anyway......Back on the road... :D

Pat thanks for info on for the sending unit...


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