Let's Talk Gauges...

What gauges are essential?
Volts, Temp, Oil pressure for me.
What brands do you trust? Stewart Warner for me.
Electronic or mechanical oil pressure?
What color faces?
In dash or below?

 

I agree, volts (I almost had my 65 GTO burn to the ground due to a faulty ammeter, I stick with a volt meter now), temp, oil pressure.
Auto Meter for me.
I had a copper oil pressure line break on me one night, what a mess! I use electric OP gauge now. If you use mechanical I'd recomend a braided steel pressure hose.
My gauges have black faces & bezels but that's entirely personal preference.
I am not a big fan of gauges below the dash. I debated long & hard before cutting 3 holes in my unmolested factory dash but I'm happy with the result.

 

After many years of chasing various gauge gremlins. I found Speedhut out of Orem Utah, granted they’re not cheap but you can customize them to your liking or they look to the average person OEM. I never have to search for the correct speedometer gear as it’s GPS. I have the volt & oil pressure gauges only all supplied with new sending units.

https://www.speedhut.com/

 

I like a big speedometer to see where I'm going with a charge indicator light, an oil pressure light, small fuel guage. Maybe a small temp guage.

I'm pulling all my extra cluster matching auto meter guages out. I don't use them.
Now if I had idiot lights for gearbox oil levels i'ld be happy.

 

At least for oil pressure I prefer mechanical. It will show momentary changes much quicker than an electrical sender. Early warning, such as low oil showing up when cornering.

Think about if you want them lighted at night.

 

I like mechanical oil, and temp gauges. When the oil gauge is installed with the correct hard line held in place with a clamp on firewall, and the correct flex line to the engine I have never had one fail, not even the one in my 47 which is probably the original 76 year old set up.

A lot of aftermarket gauges come with small copper tubing, or plastic tubing. Copper will harden over time from being heated and then cooled slowly, plastic will become brittle. When I first got my CJ5 it had an aftermarket oil gauge with the plastic line which did spring a leak and sprayed oil all under the dash. That Jeep had sat in a barn for over 40 years, so I think the plastic line had simply gotten hard and brittle.

The cluster gauges and idiot lights no longer work on that Jeep and since it already had holes in the dash for gauges I installed a new Bosch volt gauge, and NOS CJ2A temp, and oil pressure gauges. I used a new hard line made for a CJ3B (right size for a CJ5) I got from Walcks which is clamped to the firewall with an insulator under the clamp, and a new flex line to the engine.

 

We had this discussion not long ago.
Ditto on Speedhut! Their electronic gauges look like old school factory.
Here's what they look like when powered up.

Disregard tach (on steering column) - engine not running.

 

I don't know what the issue is with an amp gauge and a fire problem, but a voltage meter is more useful to me on a 12 Volt system, so I don't have an amp gauge on any of mine, with the exception of the 47 which still has all of the original instrumentation, but the only one still working is the oil pressure gauge.

 

Never heard it from that angle, although high heat and a fast quench will indeed soften it.

I do know that copper will 'work harden" and get brittle from bending/vibration, which is why it's not suitable for brake lines etc. On a gauge system, firm mounting at critical points, and including gentle loops or coils elsewhere will reduce that risk.

 

A ammeter is a normally unfused wire, carrying a lot of amps and capable of shorting the full power of the battery. But I still like ammeters and never had a problem. Yet.

A voltmeter merely samples a tiny amount of current.

I think the pertinent issue is alternator or generator? A ammeter is more useful with generators, but reveals less than a voltmeter on alternators.

 

Comes back to just amperage. What was sort of ok at 35 amps through the amp gauge is a significantly higher risk with 100+ amps out of most alternators these days. I'm another Stewart Warner advocate and I do prefer their mechanical gauges with a full sweep. I don't believe I have ever had a SW gauge fail in the 6 plus decades I have been using those.

 

I am thinking it would need a really big Fuse link or fuse. Maybe a big circuit breaker might work. I think the fire danger with ammeters is the fact there is a large amount of current that has to pass thru them. If there is any overload condition the ammeter is the weak link and can over heat causing a possible fire under the dash. Hopefully someone else can elaborate as I am no expert on this condition.

 

I must agree that the direct read oil pressure gauge gives the best immediate response to your oil pressure. However one must use a very high quality feed line, no plastic or tiny copper lines. One of the small copper ones cost me an expensive diesel engine before I caught it. When repaired I put a tee in the gauge feed line and and installed an electric ldiot light sender. I wired it thru an under dash seat belt buzzer. Ford used them before computerized engines. If oil pressure dropped below 5 psi the buzzer came on instantly.

 

One more thought and I will get off the podium. I have given thought to installing a vacuum gauge. It would be good to monitor engine status as to when optimum fuel economy was being achieved on street rigs if that is important to you.