1948 Continental Coupe Oil Pressure Gauge Replace?

[panteradave]

I have a '48 Continental Coupe with a non-functioning oil pressure gauge.  I have confirmed that the oil pressure sending unit is working and that the engine really does have good oil pressure from the oil pump.  I have acquired a NOS oil pressure gauge, but am a loss at how to make the old to new oil gauge change. 

 

I assumed that the left side gauge cluster has nuts or bolts on the back side of the dash that when removed will allow the cluster to move out of the dash towards the driver.  Unfortunately, the dash wiring and everything else that is behind the dash almost completely obscures access and even any clear vision of the back of the instrument cluster.  I have no idea where to begin, and am hoping that the first step is not 'remove the entire dash from the car'. 

 

Can anyone provide some pointers on where to start?

 

Any help would be much appreciated.

 

Dave

[Ray500]

Getting the speedometer cluster is very tricky, and can challenge anyone with large hands.  There are stud mounted brackets that hold the cluster to the dash, and once you release them the wiring is tight in some cases, but that's the only way you're going to get to the cluster to replace the oil gauge.  Some do what the ratrodders do an add an oil gauge separately under the dash as a quick fix.  It is important to have a good working oil gauge.  Might be a good idea to make sure the replacement gauge you have is in good working condition by temping it in outside the the dash to make sure it's functional.  Also sometimes bad wiring conditions cause gauges not to work which also needs checking.  

Good luck on it!

[panteradave]

Thanks for the info.  Does the speedometer need to come out before I can get at the gauge cluster?

 

Dave

[Ray500]

The cluster of gauges is part of the speedometer unit if it's original.  Most of these cars have a lot of stuff behind the dashboard, and little room to work on it just sticking your head up behind the dash and trying to work.  On my '41 I found it easier to just pull out the speedometer cluster.  I also replaced the wiring with new cabling with new exact wiring color code and wire covering that was as the original.  On these vehicles the old wiring was rubber covered, and this many years later the rubber dries up, cracks, and exposes the wiring harness to shorts and a fire.  So for safety and proper operations new wiring is essential to the restoration of your vehicle.  It updates your wiring yet it's as if it were just as original.  Nothing like reliable electrical circuits including lighting especially in these 6 volt systems.  Some quick examination of the condition of the wiring in your vehicle including around the instrument cluster can help determine the best way to replace the oil pressure gauge.  It will be easier if you can remove the cluster from the vehicle and replace the gauge on your work bench to do it properly.  

[panteradave]

Thanks again for the info!  The wiring and instruments in this Continental (and most of the rest of the car for that matter) have been restored relatively recently and are in near perfect condition, well except for the non-functioning oil pressure gauge.  My goal has been to find and finish the leftover 5% of stuff that got missed, forgotten or the money just ran out in the past at some point. The dead oil pressure gauge is one of those items.  I would prefer to not just hang on a non-original oil pressure gauge. 

 

I found some photos of the '48 Continental gauge cluster on the internet and instantly realized that the instruments must be removed from the back of the dash, not out the drivers side.  After poking around in the area between the firewall and back of the dash, as you mentioned, I can see that it is crammed with all kinds of stuff that is in the way - wiper motor,  wiper linkage, wiring bundles, steering column, overdrive cable, fan switches, etc.   It is VERY tight back there.  I definitely don't want to accidentally damage the restored bezels or painted dash surface while removing/reinstalling the gauge cluster.

 

I agree that it would be better to remove the gauge cluster and replace the oil pressure gauge on the bench.  Exactly how that happens will be more of an adventure that I had anticipated. 

 

Again, any advice/suggestions would be most welcome.

 

Will keep you posted.

 

Dave

 

 

 

 

[19tom40]

It is unusual for the gauge to go bad, can you please tell us how you tested it? Your problem could be a wiring problem or the wrong kind of sending unit, both being easier to correct than replacing the gauge.

[panteradave]

I haven't tested the oil pressure gauge directly as I am unable to access it well enough to even remove the wires.  The gauge has worked normally for the last 2 years that I've owned the car, then simply stopped moving.  I replaced the sending unit with a new one from Boos-Herrel but that didn't change anything.  I also grounded the wire on the sending unit, also without a gauge response. 

 

I then inserted a mechanical pressure gauge into the fitting on the sending unit end of the oil line from the engine.  The mechanical gauge read a normal cold-engine oil pressure of around 50 psi.    Also, all wiring in the car has been replaced front to rear within the last 8-10 years.  My conclusion at that point was while I couldn't completely eliminate a wiring problem, I thought it more likely to be a faulty gauge.  I have a Boos-Herrel NOS gauge ready to install if I can manage to get the gauge cluster out of the car.

 

Just to clarify the type of gauge cluster that is present in my 1948 Continental, I have included a photo.

 

Please keep the ideas and suggestions coming....

 

Dave

 

 

 

 

 

 

[Ray500]

That cluster gauge assembly should come out as a unit if you can get the rear brackets off that hold it to the dash so you can remove the oil gauge.  But you might also check the voltage at the gauge while it's mounted in the car if you can get to it.  One side of the gauge is connected through a resistor to the battery, the other is going out to the sensor on the engine.  You can ground the sensor lead at the gauge if you can get to it and observe the gauge to see if it's responsive.  With battery voltage on one side and ground on the other side of the gauge....if it doesn't respond then the gauge is probably the problem.  A mirror and flashlight looking up behind the dash might give you a clue as to removing the cluster.  Looks like there are some add-on controls under the dash which might have to be removed temporarily till you can get he cluster out of the dash.  Good luck!

[19tom40]

I would try to check the gauge as Ray500 describes, because you may have a loose connection at the gauge. Make sure that your sending unit has the King Seely stamp on it. Some of the other sending units are of the resistive type and besides being inaccurate can damage the dash unit when the voltage goes out of limits.

 

Here is a link to a King Seeley unit on E-Bay. The 3rd photo shows the logo.

 

https://www.ebay.com/itm/1935-53-Ford-Mercury-Flathead-V8-Oil-Pressure-Sending-Unit-80lb-41A-9278/202608065816?epid=1922969814&hash=item2f2c61bd18:g:QUUAAOSwBRlcdDFC