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All,
1966 galaxie 7 litre vert.
I just rebuilt my motor and don’t like the dummy lights in the dash. Don’t want to over heat or not know if I loose oil pressure. So I want to add electric oil and temp gauges in the least intrusive way possible.
Going for total stock in the restoration and don’t want to cut wiring, drill holes or make these changes that cannot be undone. Whom ever buys this car after me can do what they want with these changes. Put it back to stock, leave the changes or leave them so they can see temp and oil pressure.
is It possible to have dummy lights and two new gauges working at same time???
I need some ideas of choices on the gauges too. Also, looking for electrical gauges not mechanical. So far, I am looking at this SW gauge


and this one for oil


I was thinking maybe a fold down bracket for bottom of dash. That way I could fold up and not see it at shows???
Any ideas?

thanks View attachment 172189
Hello JIM4,

I have a few thoughts for you to consider. First on the oil pressure gauge and light that's easily doable. All you need is a Tee junction on the oil filter housing oil feed port to house both the original switch sender for the lamp and the oil pressure transducer for the electric gauge.

The temperature lamps and gauge will be a bit more tricky as there is only one real good port on the intake to put a sensor in the constantly circulating coolant. Since you have a heater only car you have coolant flow through your heater core at all times (unlike factory air con cars) you could rig one of the senders in line with the heater core but that's probably going to look bad.

I don't know what your expertise level is in electronics but you could use the S&W gauge sender in the original coolant switch port in the intake and then monitor that variable gauge voltage by means of high impedance comparators and set the trip points on the comparators for the COLD and HOT lamps so thier functionality is retained. With this method you could adjust the trip points and know what temperature the HOT and COLD lamps turn on and off. Of course you'll need a little hysteresis built in to the comparators and that's easy enough.

Just ideas.

Cheers
 

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Desert, thanks for the input. As always spot on. My knowledge of electronics is learned OTJ, not school trained. So, maybe you could pick out a comparator for me to purchase (It’s past my knowledge). I really like that idea, adjusting when my dummy light turn off and on based on temps. How would I connect this setup and where would I put the extra electronics? I assume it’s like a potentiometer?

thanks again.
Hello JIM4,

Everyone has really good alternatives offered to run both sets of transducers (one for lamps and one for gauges). Another side quick note is since you're using all electric gauges (which is a great idea), you can just put them all on a plug and quickly disconnect them and remove them when you want to.

How the above idea negates the possibility of using an electronic adjustable interface to operate your COLD and HOT lamps as the aftermarket temperature gauge when unplugged would really shift the input signal to the comparators input for the lamps.

If you leave all the gauges connected just find a way to fold them out of the way, then building a small electronic switching system for the dash temperature lamps is possible.

Here's a link to a good comparator that would work in this application, Mouser does have it in stock https://www.mouser.com/ProductDetail/Nisshinbo/NJM2903DQ?qs=7jPOr0kCrUCnUTKFtv3DGA==

If you need help with the basic schematic outline for some simple ESD, reverse polarity protection, etc, I'll be happy to help. You won't be able to pick all the value parts till you receive your electric temperature gauge and take some measurements over the range of it's operation as the variable voltage range the sender will alter is ultimately determined by the gauge itself.

Cheers
 

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I quite like the comparator idea for running the Hot/Cold light off the same sensor as the gauge...
Hello galaxiex,

For those who would like to do just that and not have another gauge set, I would recommend using the standard GM coolant sensor as it's used in abundance and has the same thread size as the Ford original COLD/HOT temperature switch.

Cheers
 

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Thanks Kenny and Darkar,
both good ideas and info. Does anyone know if the SW gauge will work with the factory sending unit? Or does it have to be SW one too?

thanks

JIM
Hello JIM4,

The factory sending units on the Fords with indicator lamps are just switches (either on or off). The electric oil and temperature gauge require a sender that varies its resistance with pressure (oil) or temperature (coolant). That way a voltage divider is set up between the gauge and the sender and a variable voltage depending on the sensor can vary the gauge in a similar way your fuel sender works. Although your fuel sender is an electric-thermal gauge and not electromagnetic like most aftermarket electric gauges.

As a side note the only automotive device that I'm currently aware of that use frequency are the newer mass airflow sensors (MAF) they have such a wide range it's hard to use a 0-5 volt reference signal with enough resolution to accurately convey to the ECU the correct airflow. Although the early MAF's were dual range analog voltage for more resolution on the lower end.

I hope that helps some.

Cheers
 
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