Gen III adapters for mech gauges and warning lights

[JMortensen]

I went looking for this info and wasn't able to find it, so now that I've found it, I think I'll post it here for the next guy. The task at hand is to hook up mechanical Autometer coolant temp and water temp gauges. I have part number 3421 oil pressure and 3432 water temp gauges.

 

Coolant Temp Gauge

First thing I need to do is take 3432 and throw it in the trash and buy electrical gauge 3531. The mechanical gauge apparently doesn't work as there is no available standoff adapter to go from 12x1.5 to 1/2" NPT. As much as I hate to do it, I figure the only choice is to go with the electrical gauge. Once you have the electrical gauge with its 1/8 NPT sender, then you can use Autometer adapter 2277, remove the plug just above and behind #8 cyl and screw in the adapter and sensor. The one nice thing about the electrical gauge is that it is possible to cut the wire down. Can't do that with the mechanical gauge, and the 6' tube they give you is a lot longer than necessary when you're just going from the gauge to the back of the pass side cyl head.

 

Oil Pressure and Warning Light

I do want an oil pressure warning light, and I would like to run the mechanical gauge above. I had previously run the gauge with copper line and a ferrule, but figured I'd upgrade to an AN braided stainless steel line this time. All adapters and fittings are steel, didn't want to hook up this many brass adapters as I was worried they may work harden and crack over time.

 

Here's the parts I need:

Autometer 2268 16mm to female1/8" NPT adapter

799-661501 1/8 NPT to 1/8 NPT male to male

361-961701 1/8 NPT Female Tee

555-105100 1/8 NPT male to AN-3 male adapter

Autometer 3242 30 psi oil pressure light switch

Autometer 3240 red warning light

361-968703 1/8 NPT female to AN -3

 

So the 16mm adapter screws into the block, then the male to male screws into it, then the Tee, then the switch and the AN adapter. Switch turns on the the light and the AN adapter takes the ss hose to the gauge. The NPT female to AN-3 adapter attaches to the back of the gauge for the ss hose.

 

Buying parts Monday, so if you see any glaring errors here let me know.

[RB30X]

Or do the same thing with the mech oil pressure as you did with the mech water temp and throw it in the bin as well, and go electronic.

 

Why wouldn't you, its so easy.

 

I've just wired up my dash after an LS1 conversion and gone all electronic Autometer gauges and it couldn't have been easier. The speedo even calibrates itself to my diff gears and wheel diameter etc.

[JMortensen]

In my experience the electric gauges give a vague notion of what might be going on, and mechanical gauges are much more accurate. With the mechanical temp gauge on my L series I could watch the thermostat open and close, and on the oil pressure I could see the oil pressure jump instantaneously as the revs came up. On my 2006 1500 truck the gauges react like they stuck in molasses, and accuracy is generally relegated to "middle of the gauge".

[RB30X]

You do understand how mechanical gauges work don't you??

 

The automotive industry is steering more and more towards electrical everything.

 

Even throttle control is electronic these days, let alone instrument gauges.

 

Your mechanical temp gauges has to be heated from a long copper tube before it does anything. What you're actually seeing happened 3 minutes ago.

 

Newer factory gauges are designed and calibrated according to the engine to read in the middle of the gauge. And I think you'll find those newer engines also have oil pressure at idle as well, and don't have to be revved before they read anything.

 

Did I mention electronic gauges are also easier??

Edited October 3, 2010 by RB30X

[JMortensen]

You do understand how mechanical gauges work don't you??

 

The automotive industry is steering more and more towards electrical everything.

 

Even throttle control is electronic these days, let alone instrument gauges.

 

Your mechanical temp gauges has to be heated from a long copper tube before it does anything. What you're actually seeing happened 3 minutes ago.

 

Newer factory gauges are designed and calibrated according to the engine to read in the middle of the gauge. And I think you'll find those newer engines also have oil pressure at idle as well, and don't have to be revved before they read anything.

 

Did I mention electronic gauges are also easier??

Yes, I am aware of how the gauges function. The argument that the industry is doing something means nothing to me. What site is this again?

 

With the mech temp gauge I could flip the fan on and watch the temp go down immediately. There was no 3 minute delay. I had a 190 degree thermostat, and I could watch the gauge hit 190 (exactly, not 189 or 191) then bounce down to say 175 when the thermostat opened, then build up again, and drop again. With the oil pressure gauge, the pressure is sent directly to the gauge via a hydraulic line, so the accuracy and speed of reading is a lot better than a sender IME. I wasn't saying that you needed to rev the engine to see oil pressure, I was saying you could just about use the oil pressure as a tachometer, it responded so quickly and accurately. Only problem with using it as a tach was that the oil pump maxed out at about 4000 rpm. Again, stock gauges give comparatively crappy response and accuracy that is questionable at best. If that's good enough for you, then go the easy route. I posted to help other people who may have the same problem I did finding info on running those gauges, not to argue about what "the industry" is doing.

Edited October 3, 2010 by JMortensen