Dead gauges

As I am waking up my 70 RR from a 30 year nap, I have no readings at all on fuel, temp or oil pressure. The voltage gauge works just fine.

Per suggestions in my build thread I did the change out on the Voltage regulator behind the dash. Swapped in a 7805 silicon chip and wired it in. Plugged everything back up and still nothing.

On the power input wire I have 12 volts coming in. With the chip wired in I have 5.4 volts on each positive side of each terminal when the key is turned. The oil gauge sending wire is modulating when I measure impedance leading me to believe the sensor is sending the signal, ohm range rises as the throttle is pressed.

When I pull it all out and test it on a battery on the bench I have the same readings as in dash, I am running power to the input prong and allowing the 7805 to kick down the voltage and getting 5.5 volts on positive side of each terminal. If I touch the input side of each gauge with a ground I get a quick movement of each hand. This is not happening with the Fuel gauge which I swore was moving prior to starting this.

I did search but is there a tried and true way for testing each gauge?

Thanks in advance

Phillip

I am dealing with EXACTLY the same situation as you are. I thought mine was one of the two steering column "multi-connector plugs", but I was wrong. Mine are going in & out. I'm now thinking it's a bad ground on mine. Maybe yours too.

Definitely a ground issue. The chassis of the instrument cluster attached to the dash frame provides the ground. I have added a ground wire from the backside of the instrument cluster housing to the steering column on my Super Bee.
there is also the possibility that your circuit board is faulty but check your attaching screws first. Make sure there is good contact at all points and no paint on the dash frame at the mounting points of the instrument cluster.

Lionized said:

Definitely a ground issue. The chassis of the instrument cluster attached to the dash frame provides the ground. I have added a ground wire from the backside of the instrument cluster housing to the steering column on my Super Bee.
there is also the possibility that your circuit board is faulty but check your attaching screws first. Make sure there is good contact at all points and no paint on the dash frame at the mounting points of the instrument cluster.

Click to expand...

Are the gauges not independent to the housing? (rubber spacer on each to keep it off the housing?)The board is good, one side is providing 12V the other from the sending units is providing a range of resistance readings from each.
That said I did have a jumper to the housing to provide ground to eliminate that issue before.

Don't know if this helps, but guess you already know each separate gauge (stock or after-market), needs it's own ground to work. Their grounded either by the ground contact built into the 'board', or wiring, usually connected together going to one common ground point.

Problem solved, Gauges bad, new ones arrived and nothing else done and they work properly(except gas it is not hooked up at the tank).

All up and running. All lights work as well.