Newbie requiring help! Oil pressure warning light stays on
Discussion
Hi All
I am new to the forum but have had my 1997 TVR Chimaera 400 for twelve months now. I love the car and have really enjoyed owning it over that time. It has suddenly developed an odd problem and I wonder if someone could advise on how to sort it. When the ignition is off the small orange oil pressure warning light at the bottom of the speedo is still dimly lit. When I start the car the light does goes out but comes back on when I turn off the car and stays on.
Can anyone advise where I should start looking to sort this problem? The oil pressure gauge is ok and shows good pressure.I also noticed when I opened the car door to get out this orange light got brighter.
The really odd thing is that I looked under the car to check the connection to the sensor/switch (O/S of the oil filter) and it does not seem to be there. Just a blanking bolt where to should be!. Don't know if a previous owner has done some sort of bodge or I am looking in the wrong place for the switch. Any help would be great as I am sure this light being on all the time is making my battery run flat.
Many thanks in advance
Simon
I am new to the forum but have had my 1997 TVR Chimaera 400 for twelve months now. I love the car and have really enjoyed owning it over that time. It has suddenly developed an odd problem and I wonder if someone could advise on how to sort it. When the ignition is off the small orange oil pressure warning light at the bottom of the speedo is still dimly lit. When I start the car the light does goes out but comes back on when I turn off the car and stays on.
Can anyone advise where I should start looking to sort this problem? The oil pressure gauge is ok and shows good pressure.I also noticed when I opened the car door to get out this orange light got brighter.
The really odd thing is that I looked under the car to check the connection to the sensor/switch (O/S of the oil filter) and it does not seem to be there. Just a blanking bolt where to should be!. Don't know if a previous owner has done some sort of bodge or I am looking in the wrong place for the switch. Any help would be great as I am sure this light being on all the time is making my battery run flat.
Many thanks in advance
Simon
It should be above the oil filter, location is awkward.
Problems like yours are usually bad earths, oddly enough various earths are located just by that sensor, again in a really awkward location.
Worth inspecting these first, you should also find a large earth cable in your front drivers side wheel arch area that goes to the chassis.
Picture of sensor below, just visible with orange wire, yours will be a different colour wire. .
Problems like yours are usually bad earths, oddly enough various earths are located just by that sensor, again in a really awkward location.
Worth inspecting these first, you should also find a large earth cable in your front drivers side wheel arch area that goes to the chassis.
Picture of sensor below, just visible with orange wire, yours will be a different colour wire. .
Edited by Belle427 on Sunday 30th June 08:25
Very strange one there. There should be no +12 on that lamp with the ignition off and it is a very simple circuit.
+12v from ignition..lamp..switch to earth.
A couple of tests.
+12v from ignition..lamp..switch to earth.
A couple of tests.
- pull fuse 16 and see what happens with ignition on and off.
- disconnect the oil switch (when you have found it)(White/brown wire)
Many thanks for all the responses. That has given me plenty to check through now. I will go through all the earth points on the car and give them all a clean up. Now I know where the switch position is I think I will order a new one and install it. I did have the dash out a few months ago to change the steel dash panel for a new wood one. I was sure I fitted it all back correctly, I will double check this though. I will also check fuse 16 as suggested.
I am really pleased I posted my question now. I was a bit stumped on what I should be checking first to be honest. Most helpful. This is all part of the joys of TVR ownership I know!!
This is my 4th TVR having owned some years many years ago. I was lucky enough to have owned two Griffith 500's and a 4.5 Cerbera. Even though my car is only the baby of the Chimaera's being a 400 I absolutely love it. Sounds great and looks superb!!!
Thanks again
Simon
I am really pleased I posted my question now. I was a bit stumped on what I should be checking first to be honest. Most helpful. This is all part of the joys of TVR ownership I know!!
This is my 4th TVR having owned some years many years ago. I was lucky enough to have owned two Griffith 500's and a 4.5 Cerbera. Even though my car is only the baby of the Chimaera's being a 400 I absolutely love it. Sounds great and looks superb!!!
Thanks again
Simon
In this instance I don't think it is going to be an earth issue so you could waste time chasing that.
I am liking the possibility the lamps have been switched so your first test is very simple. Disconnect the charge wire at the alternator (thin Brown/Yellow wire) and see what the lamps are saying with ignition on and off.
Steve
I am liking the possibility the lamps have been switched so your first test is very simple. Disconnect the charge wire at the alternator (thin Brown/Yellow wire) and see what the lamps are saying with ignition on and off.
Steve
I had the exact same issue, when I fixed my poor negative battery clamp/cable connection the problem went away.
Keep in mind electricity will always find the easiest path to earth, something on your TVR has a bad earth and the next best earth it can find is your oil pressure warning bulb making it illuminate when it shouldn't. You often see the same earthing issue on tail light clusters, follow a car with an earthing issue and when the driver puts his foot on the brake the indicator bulb comes on solid (often dimly).
All thats happening here is the indicator bulb has a better/easier path to earth than the brake light bulb, something is simply earthing through your oil pressure warning light bulb that shouldn't be. Correct any bad earths and normal service will be resumed, on your car the engine block is connected to battery negative terminal as follows:
1. A bolt going into the engine block holds a cable, the other end of which is bolted to the chassis at the front O/S outrigger diagonal, this is your primary engine earth cable
2. The chassis itself then becomes the earth path but of course its still got to get from the chassis to the negative battery terminal
3. So at the N/S of the transmission tunnel there's a body to chassis mounting bolt where another cable is bolted the other end of which is the negative battery clamp, this is your secondary engine earth cable but ultimately also serves all other earthing on the car as it's the only connection from the chassis the battery negative terminal.
Once more, here's how I found the condition of my negative battery clamp/cable connection....
The thing is that primary engine earth cable is bolted to the engine block right by the oil pressure switch, which is a clue by the way
Essentially you are checking the condition and tightness of four key earth connections and the two cables, I'd actually start at the battery end if I were you as your issue could easily be as simple as a loose battery clamp on the negative battery terminal. Another quick and simple test is to get a long jump lead and clamp one end firmly to your engine block, then clamp the other to your battery negative terminal, if your oil pressure warning light suddenly starts behaving normally you know you have an engine earthing issue.
Keep in mind electricity will always find the easiest path to earth, something on your TVR has a bad earth and the next best earth it can find is your oil pressure warning bulb making it illuminate when it shouldn't. You often see the same earthing issue on tail light clusters, follow a car with an earthing issue and when the driver puts his foot on the brake the indicator bulb comes on solid (often dimly).
All thats happening here is the indicator bulb has a better/easier path to earth than the brake light bulb, something is simply earthing through your oil pressure warning light bulb that shouldn't be. Correct any bad earths and normal service will be resumed, on your car the engine block is connected to battery negative terminal as follows:
1. A bolt going into the engine block holds a cable, the other end of which is bolted to the chassis at the front O/S outrigger diagonal, this is your primary engine earth cable
2. The chassis itself then becomes the earth path but of course its still got to get from the chassis to the negative battery terminal
3. So at the N/S of the transmission tunnel there's a body to chassis mounting bolt where another cable is bolted the other end of which is the negative battery clamp, this is your secondary engine earth cable but ultimately also serves all other earthing on the car as it's the only connection from the chassis the battery negative terminal.
Once more, here's how I found the condition of my negative battery clamp/cable connection....
The thing is that primary engine earth cable is bolted to the engine block right by the oil pressure switch, which is a clue by the way
- Check your primary engine earth cable is tightly bolted to the block and is clean/free from corrosion
- Check the other end of this primary engine earth cable is tightly bolted to the O/S chassis outrigger and the connection is clean/free from corrosion
- Check the condition of this primary engine earth cable itself
- Check your secondary engine earth (main earth) cable is tightly bolted to the chassis at the N/S transmission tunnel and is clean/free from corrosion
- Check your secondary engine earth (main earth) battery clamp is tightly bolted to the negative battery terminal and is clean/free from corrosion
- Check the condition of this secondary engine earth (main earth) cable itself
Essentially you are checking the condition and tightness of four key earth connections and the two cables, I'd actually start at the battery end if I were you as your issue could easily be as simple as a loose battery clamp on the negative battery terminal. Another quick and simple test is to get a long jump lead and clamp one end firmly to your engine block, then clamp the other to your battery negative terminal, if your oil pressure warning light suddenly starts behaving normally you know you have an engine earthing issue.
Thanks Steve for the info to check fuse 16 and the alternator connector. Also thank you ChimpOnGas for that very detailed guide to the earth set up from battery to engine. Saved me a lot of time finding all the earth points. This is what I have done so far.
Changed the negative connector terminal on the battery as it was rather poor condition. Run a cable from the negative of the battery directly to the engine block but the light is still on unfortunately. I did end up cleaning the earth points which were not too bad but worth cleaning just to eliminate that area.
Pulled the connector off the pressure switch (after following the picture and finding it). Light still illuminated! That switch really is fun to get at!!! Should the light go out when this connector to the switch is removed regardless of anything else?
Removed fuse 16 (dash lights etc.) and the light remained on. Removed what I think is the right connector off the back of the alternator (yellow female terminal), light still on. Don't know if this was the right one. There was a bolted in brown wire above it.
Of all these things I have tried the light stays on when the ignition is off but does go off when the ignition is turned on or the car started. So unfortunately still no joy getting the orange oil light to go out.
To be fair it does go out when I disconnect the battery completely which is good!!!!!
, but not the answer to sorting it out I know. I am resisting the temptation to take the bulb out and do want to find the problem. Had to walk away for now and think what to do next.
Thanks for all your help so far
Simon
Changed the negative connector terminal on the battery as it was rather poor condition. Run a cable from the negative of the battery directly to the engine block but the light is still on unfortunately. I did end up cleaning the earth points which were not too bad but worth cleaning just to eliminate that area.
Pulled the connector off the pressure switch (after following the picture and finding it). Light still illuminated! That switch really is fun to get at!!! Should the light go out when this connector to the switch is removed regardless of anything else?
Removed fuse 16 (dash lights etc.) and the light remained on. Removed what I think is the right connector off the back of the alternator (yellow female terminal), light still on. Don't know if this was the right one. There was a bolted in brown wire above it.
Of all these things I have tried the light stays on when the ignition is off but does go off when the ignition is turned on or the car started. So unfortunately still no joy getting the orange oil light to go out.
To be fair it does go out when I disconnect the battery completely which is good!!!!!
, but not the answer to sorting it out I know. I am resisting the temptation to take the bulb out and do want to find the problem. Had to walk away for now and think what to do next.Thanks for all your help so far
Simon
Edited by L33SGH on Monday 1st July 16:14
As stated above the sensor is just a switch that closes to complete the circuit to negative.
With the wire removed from it the light should not be on.
I would be double checking the connections at the dash lamp and see if the wire colours look correct, it is a very strange issue as fuse 16 puts the positive to the lamp.
You should have green and brown/white colours at the lamp, green being 12 volts ignition via fuse 16.
With the wire removed from it the light should not be on.
I would be double checking the connections at the dash lamp and see if the wire colours look correct, it is a very strange issue as fuse 16 puts the positive to the lamp.
You should have green and brown/white colours at the lamp, green being 12 volts ignition via fuse 16.
Edited by Belle427 on Monday 1st July 19:44
Took the dash top off today and it would seem the oil pressure / battery lights are the wrong way round. That will teach me for not being more diligent when I removed the facia panel and instruments!!.
Thank you all so much for pointing me in the right direction. This I assume would now point to an alternator fault. The one on my car dies look like an original. If it is it has lasted very well (if it has not already been refurbed before). After doing some research it would seem that a Denso alternator is the one to go for in terms of OE quality. I will let you know how I get on.
Simon
Thank you all so much for pointing me in the right direction. This I assume would now point to an alternator fault. The one on my car dies look like an original. If it is it has lasted very well (if it has not already been refurbed before). After doing some research it would seem that a Denso alternator is the one to go for in terms of OE quality. I will let you know how I get on.
Simon
L33SGH said:
Of all these things I have tried the light stays on when the ignition is off but does go off when the ignition is turned on or the car started.
Did you mean to say that? The oil pressure light should come on bright with ignition on (engine off), then go off when the engine is running.Sorry it was my mistake. I just confirmed this morning that my battery warning and oil pressure warning lights are reversed (as suggested). A cock up when I reinstalled my instruments. That being the case my oil pressure light is working as it should. Comes on with ignition then goes off when the engine is fired up. It is the battery warning light that is still on glowing when the ignition is off.
After checking other posts on the forum this has happened to others when there is a alternator problem. Unfortunately I thought it was the oil pressure switch because that light was glowing. Sorted now thanks to some good help from other members.
After checking other posts on the forum this has happened to others when there is a alternator problem. Unfortunately I thought it was the oil pressure switch because that light was glowing. Sorted now thanks to some good help from other members.
well done
Note to Simon.....you have had replies from some of the most knowledgable people on our forum.
Pistonheads tends to go into hibernation somewhat over the winter, and some people suggest it is dead, but come Spring, Summer and Autumn it is full of useful and interesting technical posts, while Facebook hits the silly season and is barely worth the effort, even for a veteran joker like me.
Nice looking car you have there. Enjoy.
Pistonheads tends to go into hibernation somewhat over the winter, and some people suggest it is dead, but come Spring, Summer and Autumn it is full of useful and interesting technical posts, while Facebook hits the silly season and is barely worth the effort, even for a veteran joker like me.
Nice looking car you have there. Enjoy.
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