Question about 1986 Ford Thunderbird

2 Answers

My 1986 Ford Thunderbird Elan shows no oil pressure on the oil gauge on the digital dash. I tried replacing the oil pressure sender, same results. There is a small block that looks like a fuseable link in the wiring that connects to the oil pressure sender. One end of it had bad wires inside and I replaced it with an aftermarket type. Still not working. There is oil pressure just not showing in gauge.

Posted by on

  • goweb Jul 10, 2010

    My 1986 Ford Thunderbird Elan is about to turn 25. It has the digital dash, 5.0 Liter multiport fuel inj. Here's the problem I'm having. The oil pressure gauge started to drop out showing no oil pressure for a few seconds and then come back. A couple of days ago it went to zero and stayed there. I don't have a oil pressure meter to test but I suspected the oil pressure sender unit and got a new one to replace.

    Before putting the new sender in I turned the engine over and lots of oil came out the hole the sender goes in. That told me its not the pump. Engine runs fine otherwise, no ticking or signs of no oil. I think the problem is electrical. The wire going to the oil pressure sensor which is next to the oil filter has a plastic block in it that looks like a fuseable link. Using a multimeter through this plastic block shows no conductivity. One end wire coming out of it is stretchy so I assumed it was burned out.

    I couldn't find that part at Ford so NAPA sold me an aftermarket fuseable link and I wired it in. Still no go for oil pressure. Where can I look next?

    PS: Thanks Duane, I'll keep that in mind but all the other parts of the gauges work. I read somewhere you can test the gauge by shorting the pressure sensor to ground. That didn't change anything in the reading.

  • goweb Jul 11, 2010

    Didn't get it right but didn't have all the facts. Best answer though so here's my vote.



2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 1,857 Answers

The way a professional would address thi is to check the pressure at the engine with a shop guage to see what is real. If still no pressure the most obvious reasons would be a bad oil pump or clogged stainer or your crank bearings are warn out. An oil service may make it a little better but as soon as the oil gets warn out the pressure will go back down.
Now if a shop gauge shows good pressure and by testing the sender the only other option would be a bad gauge, Gauges do go bad

Posted on Jul 10, 2010

  • goweb Jul 11, 2010

    That all makes sense.

    One thing that I have found out since posting this and that no one is mentioning is the fact that the oil pressure sensor outputs OHMs to the guage. The small block inline with the sensor is a resistor and if it goes out the reading on the gauge won't be accurate.

    I was able to short the sensor wire to ground and the oil pressure reading went to five bars (60%). So at this point I need to do two things. First measure the oil pressure with a shop gauge. And second. Figure out if that little resistor inline with the sensor connection can be replaced or substituted.

    Thanks everyone for the input and I'll let you know what I find.

  • goweb Jul 11, 2010

    Problem fixed. I'm putting this down for anyone else who might experience this with their older Ford.

    Putting in the new oil pressure sensor invalidated everything from then on because it was BAD. The problem was with the inline resistor (22 OHMs). One wire coming out of it was burned/broken. Good wire could be found inside the plastic resistor casing, I had to dremel tool a V notch 1/8 " into it to get to the good wire where I soldered a new wire on.

    Putting this back on still showed no oil pressure. I bought a oil pressure tester from Harbor Freight for 8$ and tested. Pressure at 200 RPM was 55. The original oil pressure sensor was put back in instead of the new one and bingo all's good.

    Thanks for everyone for your input.



  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Ford Master
  • 6,826 Answers

The gauge package on the digital dash system for the 1986 Ford Thunderbird (we have a 1985 ford thunderbird with the same setup)
might be damaged seeing that you had to replace the bad wiring and sensor. That's probably what I would have done.

That's high technology from the 1980s.

Posted on Jul 09, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

Where is the oil pressure sensor on a 1995 Chevy Truck? V-8, 5.7 L. I have the new one, just can't find the one I need to replace.

If you go to a parts store, I prefer CARQUEST, they will gladly print up a schematic or just show you where it is if that is all you need.

Feb 01, 2016 | Cars & Trucks

2 Answers

I have a 2003 ford ranger the oil pressure guage goes to hald way then 0 back to half way truck runs great with no problems

Check the plug first. Look at the tabs in the plugs. They should be touching from one side to the other. See a gap fix or replace the plug. If it looks good, Replace the oil sending unit.

Dec 18, 2015 | Ford Cars & Trucks

1 Answer

Oil pressure problem

in a shop we ignore the dash gauges and use REAL gauges.
we attach a real gauge to the sender port. on engine block.
and read the true pressure.
the lamp on most cars go on at 3 to 5psi.
this is catastrophic failure. that low.

my guess, is you let oil drop and you wrecked bearings.
but let the real gauge prove that , dont guess.

Jul 14, 2014 | 2001 Isuzu Trooper

1 Answer

Fuel sending unit replacement 79 thunderbird, must you drop the tank?

Hi Gary , looking at a tank for your vehicle iwould say you would have to drop it to replace the sender unit unless there is an access panel under rear seat or in the trunk , before installing new sender connect up to the wiring and check the dash fuel gauge as you move the float up/down to make sure it works ok ,nothing worsr than tank back in and not reading on gauge keep me uptodate Steve

May 03, 2014 | 1983 Ford Thunderbird

1 Answer

1988 dash lights are out digital typ

If the headlight switch is replaced, and it doesn't solve the problem, check the bulbs in the dash behind the gauges.

Mar 23, 2013 | 1986 Ford Thunderbird

1 Answer

I've had sender replace and all points between there and oil gauge verified OK and all the stepper motors on instrument cluster replaced but still get fluctuating oil pressure needle and warning s

If you check the oil pressure with a mechanical gauge and the pressure is steady, the problem would be in the gauge on the dash if you have replaced the sending unit and there are no problems with the circuit.
The mechanical gauge could verify a problem with the actual pressure in the engine.

Aug 22, 2012 | Cars & Trucks

2 Answers

1986 ford thunderbird oil gauge on and beeping

I would check that the engine oil level is high, then I would check that the pressure is high enough by plugging a gauge into the oil pressure switch socket after removing the oil pressure switch.

There is a possibility that the oil pressure switch is bad, or the oil pump has failed, unfortunately.

Oct 13, 2010 | 1986 Ford Thunderbird

1 Answer

Oil light blinks on and off could pressure switch be bad if so where is it located on a 2000 ford windstar 3.0

Oil Pressure Switch Operation:
00134_oil_pressure_switch_gauge.jpgInformation relay unit for the indicator light or gauge on instrument panel. It contains a diaphragm that responds to changes in oil pressure. When the oil level is over a pre-set limit, the diaphragm opens the switch, turning off the light. When level is below the pre-set limit, the dash light comes on. In later model cars, if the oil pressure drops, the switch turns off the fuel pump, to stop the engine and limit damage to internal parts. Oil pressure switches can be grouped into two categories, units for electrical gauges and for mechanical gauges.

Oil pressure can be checked at the sending unit passage with an externally mounted mechanical oil pressure gauge. To get accurate results from the test, make sure you follow the manufacturer's recommendations and compare your findings to specifications.
Testing the Oil Pressure Gauge
  • Test the gauge by grounding the wire that leads to the sending unit on the block.
  • When the wire is disconnected from the sending unit with the key switch on, the needle on the oil pressure gauge should be either all the way high or all the way low. Grounding the wire should make the needle move to the opposite side of the gauge from where it was before the wire was grounded. If the vehicle is equipped with an oil pressure light, touching the wire to ground and then removing the wire from ground should turn the light on and off.
  • If either happens, the gauge and wiring are good and the sending unit is at fault.
Testing Oil Pressure
Pressure can be tested by temporarily installing an oil pressure gauge in place of the sending unit. Before testing, look up the oil pressure specifications for your vehicle in the appropriate service manual.
  • Bring the engine up to operating temperature.
  • Now shut the engine off.
  • Locate the oil pressure sending unit; usually it is on the lower side of the engine block.
  • Disconnect the wire from the sending unit and use an open ended wrench to remove the sender. Using pliers can damage the unit.
f43-19.jpg An oil pressure sending unit is removed with a special socket. Courtesy of Chrysler Corporation.
  • Tighten the oil pressure test gauge into the hole in the block where the sender was removed.
f11-15_3184.gif Measuring oil pressure. Reprinted with permission.
  • Check the engine's oil level and fill, if required.
WARNING Be extremely careful when working near a running engine. Always wear safety goggles or glasses with side shields when working around moving machinery and be sure that your clothing is not loose.
  • Now turn the engine on and check the oil pressure on the gauge.
    • Watch as the engine warms to note any excessive drops due to temperature.
    • Make sure the engine speed is set to specifications for testing pressure.
    • If necessary, us a tachometer and adjust the engine idle speed.
  • Record the measured oil pressure, then turn off the engine.
  • Compare the test results with the manufacturer's specifications.
    • If the oil pressure is within specifications, this shows that the oil pressure sending unit may not be working correctly.
    • In many cases, replacing the oil sending unit will correct the problem.
  • After the test is complete, reinstall the oil pressure sending unit, start the engine, and confirm there are no leaks.

Nov 17, 2009 | 2000 Ford Windstar

1 Answer

Oil pressure slow to rise

you need to try a external gauge to check the pressure to see if your dash gauge is right

if the engine took 10 minutes to get oil pressure it would be dead by now i would replace the oil pressure sender unit first

Dec 30, 2008 | 2001 Ford Ranger Regular Cab

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

162 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

80637 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers


Level 3 Expert

5687 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides