guage troubles
Thread Starter
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5th Wheeling
Joined: Apr 2003
Posts: 49
Likes: 3
guage troubles
I am pulling my hair out........and theres not much left! 
the oil pressure dropped on my 89 F250 7.5,
after checking the sending unit I found it seeping around the stud.
So I replaced it with a new one, but it only worked for a few miles and started reading low on the dash guage.
Break out the Ford manuals and do all the check this and that,
it says that it should have 11-14 volts to the sending unit.
All the other guages work perfectly, but not the oil pressure.
Retest and replace the panel guage. still does not read.
it has 65# at start up with live pressure gauge attached.
sending unit shows resistance vari's with rpm.
Wire is good to panel but still get only 6.4 volts to sender.
but the darn dash guage will not show pressure and the engine light stays on.
it has the resistor on the back of the dash panel and it reads 20 ohm's like the book shows.
So now I'm out 250 bucks for parts and alot of Hair.
HELP!
Thanks.
the oil pressure dropped on my 89 F250 7.5,
after checking the sending unit I found it seeping around the stud.
So I replaced it with a new one, but it only worked for a few miles and started reading low on the dash guage.
Break out the Ford manuals and do all the check this and that,
it says that it should have 11-14 volts to the sending unit.
All the other guages work perfectly, but not the oil pressure.
Retest and replace the panel guage. still does not read.
it has 65# at start up with live pressure gauge attached.
sending unit shows resistance vari's with rpm.
Wire is good to panel but still get only 6.4 volts to sender.
but the darn dash guage will not show pressure and the engine light stays on.
it has the resistor on the back of the dash panel and it reads 20 ohm's like the book shows.
So now I'm out 250 bucks for parts and alot of Hair.
HELP!
Thanks.
Posting Guru
Joined: Jun 2004
Posts: 1,781
Likes: 1
From: Central NY
Sorry but it sounds like you might have the wrond sending unit. The ford truck unit is mearely a switch: when there is some oil pressure (>4# I think) it will short and the guage will read somewhere in the normal range.
It sounds like you might have the 'true' sender installed now. If you short out that 20ohm resistor does the guage now work correctly? If it does you might as well leave it shorted and have an better guage for it. (this is a know 'fix' for the factory guage)
If it still does not function correctly then I would check/clean the battery grounds to body (by the battery), frame, and block (follow the neg cable down)
Let us know what you come up with.
Popa Tim
It sounds like you might have the 'true' sender installed now. If you short out that 20ohm resistor does the guage now work correctly? If it does you might as well leave it shorted and have an better guage for it. (this is a know 'fix' for the factory guage)
If it still does not function correctly then I would check/clean the battery grounds to body (by the battery), frame, and block (follow the neg cable down)
Let us know what you come up with.
Popa Tim
Thread Starter
|
5th Wheeling
Joined: Apr 2003
Posts: 49
Likes: 3
Well I have it fixed.
I did replace the sending unit with a guage type.........after all there is a guage on the dash.
But even shorting the 20 ohm res did not make it read on the dash and there was 65# of pressure on the live guage.
So I replaced the sender with a Light type and it reads like it always did.
and the engine light went out.
Thanks Ford........16 years and I thought that that guage on the dash was supposed to be reading true pressure.
So I am going to mount the live guage under the dash so I will KNOW what the oil pressure is doing BEFORE it has no pressure and the engine light comes on.
Thank
I did replace the sending unit with a guage type.........after all there is a guage on the dash.
But even shorting the 20 ohm res did not make it read on the dash and there was 65# of pressure on the live guage.
So I replaced the sender with a Light type and it reads like it always did.
and the engine light went out.
Thanks Ford........16 years and I thought that that guage on the dash was supposed to be reading true pressure.
So I am going to mount the live guage under the dash so I will KNOW what the oil pressure is doing BEFORE it has no pressure and the engine light comes on.
Thank
