Hey guys. I'll be starting my custom gauge cluster build here soon and am looking for any advice and suggestions. I also have questions. First of all electric or mechanical aftermarket gauges? Along with gauges how to wire in warning lights for oil, temp, fuel and volt? Thanks guys

 

Use mechanical guages where you can like oil pressure, and water temp. Some gauges have to be electrical. You'll find that if you try to buy guages that have electrical sending units they more than double in price.


Warning lights for oil, and water temp are ground based. You run one wire from the sending unit which is a ground to the ground terminal on your lights. The other light terminal is a key on hot. So basically with the key on the power to the light is on. In the case of an oil pressure light, the sending unit ground is on turning the light on until you get oil pressure. Just the opposite with a water temp warning light. It stays off until you hit 225* or so, then it turns the ground on turning on the light.

 

I suggest running electrical gauges. Wires are much easier to run than the various hoses; This keeps fluids out of the cab if your oil capillary ruptures as well.

 

I second the electrical gauges. I've had a mechanical oil pressure gauges leak on me and I dripped oil on my carpet.

 

I swapped to newer 90's style gauges...

I would not recommend that to anyone :P But I don't have a 5v regulator and now have a voltage gauge instead of the ammeter. But the reason I went this way was because the fuel tank sending unit resistances are different between the old fords and new.

Think lots of dremeling, JB welb, soldering, cursing, several trips to the jy for more cos mine don't fly well.

3x Electrics to keep oil and other noxious engine stuff out of the cab.

 

I seem to trust mechanical gauges more than electrial gauges and have had a few electical gauges that were very expensive but I could never get them to be accurate.

That said a busted oil guage line in the cab would be a huge mess.

When buying gauges make sure you see if the electric guage comes with the sending unit or not. That can make a big deal on price.

Another note... for a mechanical water temp guage it has a large probe on the end of the signal tube... this requires a much larger hole in the firewall than an electric temp gauge.

 

So in other words you ground the lights to the sending unit and then you wire a hot wire to it from the key?

 

Thanks for all the input guys. I'm getting a set of electrical Marshall gauges. How do I wire up a speedo and tach

 

Any electric speedometer or tachometer i ever bought always had there own instructions to wire them up . That's what i would follow as for the speedometers they are not always the same with different brands and mine had a sending unit [pulse generator] at the transmission.____JIM.




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At least stay with gauges instead of idiot lights. While I prefer a mechanical oil pressure and temp gauge with voltmeter instead of amp, I refuse to trust an idiot light for oil pressure. Most are set to cut on at 5psi and the damage is already done before you can even pull over. Lost one engine due to this, won't happen again.

 

I'm installing them along side the gaug .

 

I went with mechanical oil and water based on experience. That is, I have more confidence in the mechanical oil pressure, for example, than I do in an electrical sender. The trade in not losing my engine due to low oil pressure (not uncommon in a 351m) is worth the risk of the capillary tube failing. However, to mitigate this, one could use a copper tube versus the typical plastic one. I still have plastic, but I ran it inside a slightly larger rubber hose sealed on the gauge end and open on the engine side of the firewall. So at least a failure will keep the oil on the engine side.