64 dash tach light is dim

[mmanship]

took my car out in the dark for the first time. I have all dash lights, including the dash mounted tach light. But, it is really dim. Are they all dim? Bulb is teeny. Maybe get a more powerful bulb of same size. It so dim one cannot see rpm. Anyone have an idea?

 

[sp6t1348]

Ground fault?

 

[4onthefloor]

Mine has always been kind of dim too. The bulb as you said is pretty small. I have been wondering if I could get it a little brighter too. Cant be too bright or it will light up your face ! Its almost time to get the car down off the lift so I may start experimenting.

 

[Mearl]

I had a problem with the dash lights being dim on the 67 Camaro. I found a GM service bulletin that said to run a new ground wire, I did as it instructed and they got brighter.

 

[yellow wagon]

Wonder if you could swap the original bulb out for an LED?

 

[61BUBBLE348]

I've been called a tail light before, not as bright as a head light.

My tach light is not bright either, but hay, whose watching the tach, I listen to mine.

 

[mmanship]

Merl, like the grounding solution a lot. I put a bigger bulb in and that helped.....some. I am clueless electronically. Are you saying a dedicated ground to the tach? Or, somehow providing additional ground to all dash lights via one ground wire?

 

[Jim Sullivan]

I would try running a temporary jumper from the tach to a good ground under the dash to see if it makes a difference. Since the gauge cluster is fastened to the dash with screws and plastic inserts, it would not be grounded without a separate wire in the harness. The ground wire in the harness may not have a good enough connection.

 

[Mearl]

Merl, like the grounding solution a lot. I put a bigger bulb in and that helped.....some. I am clueless electronically. Are you saying a dedicated ground to the tach? Or, somehow providing additional ground to all dash lights via one ground wire?

You just need to run a wire from the metal case of the instrument cluster to a screw or bolt somewhere on the main part of the dash panel. To test and see if it will help, you can touch a wire at the back of the cluster and the other end to any unpainted surface; that will supply a ground.

 

[Phil Reed]

The tach bolts directly to the tach housing. The problem is the tach housing has a rubber gasket so the only "ground" it gets is thru the 3 screws that mounts it to the dash. Just try a ground wire from the back of the tach to the dash.

 

[Clyde Waldo]

Most of the tachs that I have played with have four wires 1) power (red), 2) ground (black), 3) power to the internal bulb, and 4) tach signal. I believe the lamp and the tachometer circuit both depend on the ground (black) wire for ground. I believe the housing is electrically isolated from the internal circuitry and the black wire is the only dependable ground for the tach circuit and bulb.

 

[Iowa 409 Guy]

Good info.................I may try a ground wire from myself to the earth.................never was too bright....

 

[Phil Reed]

I just thought low voltage was your problem???????????????? Where's Mary when we need her?????????????