On a flathead Ford V8 since there are two separate water systems a lot of people run two temp. gauges. Would it be possible to run through a switch and have two electric sending units wired into one gauge? I don't have anything but mechanical temp gauges and I am not that familiar with electric. I don't think I have ever even wired an electric one in. It would be on a blown flathead with an alternator and serpentine belts so I an not worried about the period correct thing running an electric gauge. I am thinking there might be feedback from one side to the other.
Yes, if the electric senders both electrically match the electric gauge chosen. A single pole, double throw (SPST) toggle switch works for this situation (only one sender is connected to the gauge at a time, so there is no "feedback").
I guess I don't understand why you wouldn't want to have 2 seperate gauges so you can see at a glance what the temp is on both sides instead of having to switch it to see?
Yes it works well. I did one for a customer like that last year. The gauge package he wanted to use only had one temp gauge so I ordered another sending unit and wired it all together with a switch to have the gauge reading only one sending unit at a time.
I seem to remember a pic of a gauge that had two needles, one for each side. If you could find one of those dual gauges you wouldn't need a switch, you could see both at the same time....
The way Henry did it one sending unit was basically a switch that completed the circuit to the other normal sending unit. If the switch side activated the circuit went open and the gauge went to full hot.
I recently stared my blown Flathead for the first time. The blower is a H&H S.C.oT . The driver side pump pulley did not have enough of a belt wrap around. After two miles of driving, the second gauge told the tale and prevented possible failure.
Do you mean like this : They were usually used on two cylinder snowmobile engines. I've been looking for one for a while now, but the only ones I have found measure exhaust temperature, not water temperature.
I am running one guage with sending units for left and right side 20180317_234047 by Chappy444 posted Mar 17, 2018 at 11:42 PM 20180331_124831 by Chappy444 posted Jun 26, 2018 at 8:24 AM 20180407_181015 by Chappy444 posted Jun 26, 2018 at 8:24 AM Chappy
I wired my flathead with two senders and one gauge. I was surprised that there was a lag when switching senders. It took a little time for the new sender to read right. Worked fine.
Wow! Westach wants $122 for a dual gauge. I know it won't be much help to the O/P, but I'd look in a snowmobile Salvage Yard (yes, we do have them in Minnesota).
I never knew this all the motors I have pulled and dealt with had been hacked on before I got to them.
As stated SPDT switch with 2 senders, I did it on my Flattie and also used a SPDT switch for high and low beam headlight relay trigger. One suggestion is to mount the toggle sideways so it's easier to remember what side your reading.
Yes it would be totally possible with electric gauges. Use a 3 position switch closed open closed. Run each sender to a closed position on the switch, open no gauges closed #1 activates the #1 head and closed #2 activates the #2 head (or #1 and #2 senders if you prefer.)..
Thanks for all the reply's....kinda was my thoughts on the approach to monitor both the banks of my flattie......
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