Oil pressure sending unit.

[brandonstc]

I have a 1949 ford pickup that has been converted to 12v and my oil pressure gauge is giving me bogus readings. Could someone please tell me if the sending unit I found on eBay will work with the original gauge? http://www.ebay.com/itm/VDO-type-Oil-pressure-sender-sending-unit-0-80-psi-input-10-180-ohms-output-/251046822857

 

[Ross F-1]

Nope. There are many vendors selling repro'd original senders.

When you say "bogus readings", are they just off? Mine are too after 12v conversion, and they probably were when it was 6v. You can adjust the indicated pressure by removing the gauge unit from the dash, when you do you will see a hole in the back of the gauge and a sawtooth wheel inside. Very small adjustments make fairly large differences.

 

[donald1950]

put a resistor on the power input to the gauge so you will have 6volts feeding the gauge then it will be correct

 

[brandonstc]

Sometimes it reads 80 psi and sometime 30 and sometimes 0. All these times the mechanical gauge on the engine reads 45 psi.

 

[joe plumber]

When I changed my 55 f100 to 12 volts I was able to purchase all repop 12 volt original looking gauges .

 

[texas webb]

I usually trust the mech gauge.

 

[chap52]

Donald 1950 hit it on the head. You can get a voltage resistor that will do all of them or individual voltage drops for each one.

 

[Brooks]

Put a constant voltage regulator in the 12volt hot lead to your gauges, it will put 6 volts for your gauges. You can buy one at NAPA it is use on ford trucks and cars up thu 1975 or later. Dennis Carpenter has them for $20.00.

 

[Ross F-1]

I guess I assumed you'd already addressed the voltage supply to the gauges. I had poor luck with the new CVR's, usual story, cheap chinese crap, mine was from NAPA. I bought an electronic regulator off eBay (http://www.ebay.com/itm/Ford-Instru...r_Truck_Parts_Accessories&hash=item3f41405095) and it works fine. But if you still have to address the heater fan motor and 6v windshield wipers, or 6v radio, nowadays I think one of these makes more sense. They can handle all the 6v accessories including the gauges: http://www.ebay.com/itm/Voltage-Reducer-Regulator-12-VOLTS-to-6-VOLTS-20-AMPS-/131351858723

 

[estout81]

As Ross said, the gauges are adjustable. Apply 1.5 volts, should read 1/2 scale 3 volts full scale. I also use a constant voltage regulator off an older Ford. Works fine on my '48 converted to 12V.