Gauges

4x4M38 · Post by **4x4M38** » Sun Jun 12, 2016 6:10 pm

I bought a box of parts containing several fuel gauges.
I divided them in half. Those with Packard connectors and
those with Douglas. There was one with screw terminals I am
assuming is an earlier 6 or 12 volt.

The Douglas gauges are of three types. One is an early M38
gauge with the large receptacle on the back for the resistor
fitting. Part number 7728852, AC number 1517270. It does
not have LEVEL but FUEL on the face. I thought all of the
24 volt fuel gauges had LEVEL on them.

Does anyone else have one of these early resistor fuel gauges?
Does it have LEVEL or FUEL on the dial?

The other thing I see is the orientation of the connectors
is not consistent.

I was thinking of lining these up and noting the part numbers
and AC numbers and taking photos for reference. Is that
something anyone is interested in?

Kendall · Post by **Kendall** » Sun Jun 12, 2016 6:50 pm

The fuel gauge in my 1951 is 7728852 and says FUEL on it (and if I remember correctly has the resistor in the back) and in my 1952 it is 7728852 but reads LEVEL.
Kendall

4x4M38 · Post by **4x4M38** » Sun Jun 12, 2016 8:41 pm

Hi Kendall,
Thanks!

There should be an AC number at the bottom of the gauges
as well.

Take care,

Kendall · Post by **Kendall** » Mon Jun 13, 2016 6:18 pm

The one that says FUEL is AC 1517270, the one that says LEVEL is AC 1517561.
Is the one that says FUEL really 24v or is that the reason for the resistor?
Kendall

4x4M38 · Post by **4x4M38** » Mon Jun 13, 2016 6:32 pm

Hi Kendall,
I believe the general thinking is the original M38 gauges with
resistors were 6 volt gauges using a 90 ohm resistor to use
with the 24 volt M38.

Take care,

4x4M38 · Post by **4x4M38** » Mon Jun 13, 2016 6:38 pm

Sorry 95 ohm resistors.

Btw, Brent Mullins sells the proper temperature sender for
the early gauge and Ron Fitzgerald sells a reproduction early
temperature gauge with resistor.

Post by **wesk** » Tue Jun 14, 2016 12:37 am

Correct, the early M38 gauges were 6 volt with an external resistor. The later were the same voltage with an internal resistor.

The sealed 6 V gauges were used on late WWII and early postwar 6 volt MV's including the CJV35. It made sense to just add resistors when the 24 V system were implemented at the end of the 40's.

4x4M38 · Post by **4x4M38** » Tue Jun 14, 2016 1:41 pm

Ron Fitzpatrick, of course.

My bad.

The Meister of the G503 site.

4x4M38 · Post by **4x4M38** » Fri Jun 17, 2016 5:56 pm

I've been sitting here in the AC with a meter and 12 volt
power supply playing with my box of gauges.

Some work, some don't. Without a sender connected they
should go to full or over full reading when power is applied.
Several are dead.

I have a sender, AC model C 7524909 with Douglas
connector. Hooking up the working gauges and that
sender to 12 volts and moving the sender through
full travel I've found as expected most only go to 1/2
full reading with the sender at full travel.

However, I found one gauge that performs correctly
from empty to full with that sender.

SW 505-V
MS24544-1
423736

It has Packard connectors and the light windows.

I have another similar gauge MS24544-2 that only goes
to 1/2 full.

Wonder if that dash 1 gauge is a 12 volt or just a quirk.

Anyway, for what it's worth, I found one MV gauge that
works on 12 volts with an MV sender for 24 volts.