Gauge Wiring Question

[Ferrino]

I'm currently replacing an older 71-73 oil temp/pressure gauge with a Carrera gauge, and had a couple of questions:

1. The Carrera gauge has 2 bulb sockets to illuminate the 2 gauges, whereas my early gauge only has one. Presumably I can just pick up a 2nd bulb holder and splice it into the single black/blue instrument light feeding the current gauge backlight?

2. There are 2 ground connections on the back of both gauges, but I only have one of them connected to ground on my current setup - presumably they are both connected internally (or through the body of the gauge) and therefore only one connection is necessary?

3. The bulb socket for the generator/alternator warning light is sized differently on the early and Carrera gauges - it fits snugly in the early gauge and is too loose in the Carrera gauge - are there differently sized bulb holders of the "2-spade" style (where the light is not grounded through the body)? Or should I just wrap the holder in tape to make it fit?

Thanks!

[RichardNew]

Here's an article I wrote a few months back about gauges. Keep in mind that you can cause more damage if you're not careful.

Richard Newton

[Ferrino]

Thanks, that's actually a youtube video link though :-)

[timmy2]

Originally Posted by Ferrino

I'm currently replacing an older 71-73 oil temp/pressure gauge with a Carrera gauge, and had a couple of questions:

1. The Carrera gauge has 2 bulb sockets to illuminate the 2 gauges, whereas my early gauge only has one. Presumably I can just pick up a 2nd bulb holder and splice it into the single black/blue instrument light feeding the current gauge backlight?

Yes, you could do that. Splice with solder and heat shrink... Have you done the in line fuse for the instrument lights yet? (search for it)

2. There are 2 ground connections on the back of both gauges, but I only have one of them connected to ground on my current setup - presumably they are both connected internally (or through the body of the gauge) and therefore only one connection is necessary?

Check the 2 connections for continuity with a meter. If they are the same point then yes.

3. The bulb socket for the generator/alternator warning light is sized differently on the early and Carrera gauges - it fits snugly in the early gauge and is too loose in the Carrera gauge - are there differently sized bulb holders of the "2-spade" style (where the light is not grounded through the body)? Or should I just wrap the holder in tape to make it fit?

There are different lamp holders, the tape may slide off with heat parked in the sun. Some adhesive lined heat shrink might be better if you can't find the correct lamp holder.

Thanks!

Hope that helps.

[RichardNew]

I sure screwed that one up. Here's the real link to my article on gauges.

Richard Newton

[Ferrino]

Thanks for the article.

Timmy - thanks. Yes, the 2 grounds are both connected, so that explains only one being wired up to ground. And yes, I recently became aware that the instrument lights are not fused and will remedy that. Wow, even gauges are not immune from the "slippery slope" - LEDs anyone?