Dashboard lighting

[Dand685 0]

I have a 97 520H. Probably one of the  last of the great ones. It has a different steering wheel, much thicker then previous years, also belt cover and different rubber footpads. Problem is dashlights all come on when turning key to start, but then when engine runs all remain bright but the oil pressure light constantly blinks. Occasionally the dash lights will all go off and stay off after engine is running. My 9 pin connector has top left(no.1?) wire cut and removed. I took the oil filter off, felt for the switch and found wire intact and connected. Impossible to see the color. I’ve jiggled the nine pin, no luck. Some times the safety switch on the trans control behind the vertical dash panel seems to solve the flashing oil light and steady rest of the lights. I’ve replaced the ignition switch twice, but wonder if there’s a special one year only ignition switch. I have wiring diagrams, I’m pretty good on tracing, but with faded colors on the wires entering the 9 pin connector I’m not sure which it is.  I need an actual diagram of the 9 pin to see what goes to and came from. What to try next? Engine runs fine, powerful, no issues otherwise.

[953 nut 62,512]

This wiring guide should be helpful.

 

[lynnmor 8,133]

The oil pressure switch supplies the ground to the hour meter thru the black wire when there is oil pressure.  The oil pressure switch also supplies the ground to the oil light thru the dark blue wire when there is no pressure.

 

[Dand685 0]

Thanks both of you. So there’s no set location in the 9 pin connector for locating the wires, just make sure the second half location matches the first. But I’ve never had a Wheelhorse that lit up all the indicator lights. What sets that off? The owners manual just says a defect will record as a flashing light on the appropriate signal. It doesn’t say they all light up. Also, I thought a ground was just a ground. The wiring diagram specifically says the oil pressure black ground goes to the hour meter. Is it possible I have the wrong black ground on the hour meter? It works just fine recording time running.

[lynnmor 8,133]

On the two items being discussed the ground side is switched while the positive side stays connected, this method greatly simplifies the wiring.  The hour meter should not run if the engine is not running.  All of the display lights up briefly when turning the switch on.  Some of the wires may be different colors across the 9 pin connection.