| Author | Message | ||
     Alan Rowson New User Username: arowson Post Number: 4 Registered: 4-2016 |
Silver Shadow 2, in Malaysia, ambient temp 30+ celsius With the engine running, the oil pressure warning light is on and the air con fans don't run. If the oil pressure switch is disconnected the aircon fans run and the oil pressure light is on. If the air con is switched off, the oil light remains on, when the engine is running. The oil pressure is showing the normal good pressure on the gauge. Ideas anyone. | ||
| Omar M. Shams Grand Master Username: omar Post Number: 1108 Registered: 4-2009 |
Your oil pressure sender unit needs to be replaced. | ||
| John Grieve Experienced User Username: john116 Post Number: 50 Registered: 4-2012 |
There's three oil pressure senders on a Silver Shadow II. One for the gauge, one for the light, and one for the petrol pump cut-out. http://60.240.221.94/RR_oil.jpg | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1621 Registered: 5-2012 |
I'm not so optimistic that the sender unit is at fault here. The sender unit is just a switch that completes the circuit to earth. So current flows through the oil pressure warning light bulb, through the switch to earth. When the engine is started the oil pressure pushes the switch to it's off position, breaking the circuit and extinguishing the warning bulb. Alan has simulated this by pulling the wire off the oil pressure switch. The fact the warning bulb stays on means there must be an alternate path to earth. I suspect a wiring fault. Alan - when you pulled the wire off, did you make sure it did not come into contact with the engine block? At some point you would have moved away from it to check if the oil light was still on. Geoff | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1622 Registered: 5-2012 |
John makes an important point - are you sure you disconnected the right wire. | ||
| Alan Rowson New User Username: arowson Post Number: 5 Registered: 4-2016 |
When I pulled the wire off, I made sure, it was not touching the chassis or anything. I later separately connected the cable to earth and the symptoms were the same. I definitely disconnected the correct wire, the colours were carefully checked. Today I will swap the connections of the 2 oil pressure switches. If the switch has failed, then the petrol pump won't work. I suspect there is another relay, or diode at fault, but it is difficult to determine which. I was hoping someone had had a similar experience. | ||
| Alan Rowson New User Username: arowson Post Number: 6 Registered: 4-2016 |
When I swapped the oil pressure switch connections, the air con worked perfectly, with the oil light not illuminated. The engine stopped running after a few minutes, due to fuel starvation. So, pretty certain, the oil pressure switch has failed. It was then impossible to unscrew the switch, so I had to remove the complete filter assembly from the car & only managed to get both of them out after applying some heat. Removal of the oil pressure gauge sender, requires a metric spanner, and that was similarly tight, but the larger hexagon enabled it to be removed with a knock on the spanner (before using heat). By some miracle, we have been able to find replacements in Malaysia, that are made in Japan. They are type TGS-94T supplied by GEN TRADING CO., LTD. JAPAN and according to the box, are sold all over Asia and the Middle East. 2 pieces cost me the equivalent of US$12! They are mainly sold in Malaysia for Land Rovers. If anyone needs further info, please let me know. Tomorrow, we will reassemble everything and hopefully all will be OK. To those who responded, thanks for your interest. Alan. | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 165 Registered: 7-2012 |
The fuel pump relay oil pressure switch operates a relay that powers fuel pump. In event of vehicle roll over or serious accident, the assumption is the engine will stop, the oil pressure will go to zero and the relay powering the fuel pump will cut off feed so that pump will stop operating. | ||
| Alan Rowson New User Username: arowson Post Number: 7 Registered: 4-2016 |
Everything now reassembled, with new oil pressure switch and running OK. |
