I posted this (following 3 paragraphs) in the Touring forum yesterday - I think this forum would have been a better choice and I'm hoping someone that's good with electrics can help me.

"I have an '06 FLHTCUSE with 30k miles on the clock. Recently I noticed my oil pressure gauge is reading zero and my air temperature gauge is reading maximum. The oil pressure warning light is not illuminated when the engine is running..

I recently had a 200 mile ride in heavy rain and wondered if some water had got into the electrics. I've had the fairing off and the fuse box to check for water but there's no obvious problems there. I've taken the oil pressure sender connection off but there's no obvious problem there either.

My gut feeling is that this is a wiring problem. I'm not concerned about the air temp gauge but I am worried about riding the bike if there's no oil pressure. "

Since then I've done some checks on the bike .

If I remove the plug from the oil pressure sensor and ground out the warning light connection, the warning light comes on. If I ground out the pressure gauge connection it makes no difference to the gauge - not even a flicker!

If I connect a voltmeter inline between the plug and the sensor on the warning light circuit, the reading is 12 volts with the ignition on but the engine not running. With the engine running, the reading is 0.05 volts. Resistance with my multimeter on the 20k ohm setting is -1 with the engine off and rises to 1 with the engine running.

On the gauge circuit if I connect the voltmeter in line, the reading is 0v with the ignition on and around 1.1v at idle and about 0.1v higher at 3k revs. Resistance with my multimeter on the 20k ohm setting is 1 with the engine off and stays at 1 with the engine running.

I'm afraid I don't understand these figures, I'm hoping there's someone here who can help me. I do wonder whether there should be 12v on the gauge circuit side as there is on the warning light circuit.

My gut feeling is still that this is an electrical problem rather than a problem with oil pressure but that could be expensive if I'm wrong.

I'm going to take the fairing off tomorrow to examine the gauge side - the oil pressure and the air temp gauges. Is there an easy way I can test these please?

Appreciate any help that anyone can offer

Cheers

Neil

 

As for oil pressure, the lifters would collapse and the motor would sound like it was coming apart in a very short time if the oil wasn't pumping. Plus your oil light isn't flickering.

I suspect you've got an electrical ground problem, particularly because the temp guage is maxed along with the pressure guage not working.

 

Took the fairing off today and did some more checking. There appears to be no short between the wire from the oil pressure gauge to the pressure sender switch and there's good conductivity between two ends of that wire. I also started the engine with a separate wire between the gauge and the sender and still got no reading on the gauge. So that seems to be the wiring ticked off as no problem.

Neil

 

Same thing here ever find the issue?

 

Well it's been about 11 years since he worked on it. I bet he bought a new one by now.

 

right….…..but buying a new one has nothing to do with him figuring it out on the last one. Unless he’s dead or in a coma, I’m assuming he remembers posting this and the issue.

 

The tests were very detailed but the OP never stated whether there was 12 volts at the actual gauge. At least I don't think he did - mentioned taking readings "inline" which is different from across a circuit.

Checking that was gonna be my suggestion since he'd covered everything else. I didn't pay attention to the age of the thread either till I'd read all the postings. People do searches and when finding something exactly relative, it's easy to forget to look at the date of the posts.

Btw - assuming it's original, that gauge is a standard VDO so looking straight at the back, (+) on the left, (S) on the right and (gnd) center. If there is +12 and ground at the gauge, grounding the S terminal should peg the needle full pressure. I have no book that late of a model therefore no idea of the wire colors.

And, pre- '99 Evo oil pressure gauges were floating ground so grounding the S would peg the gauge to zero (in case someone in Evo land gets lost doing a search years from now)

 

It's been 10 months since he logged on.. You might be waiting for a while.. He may be dead..