W123 fuel pump relay?

[njpumphrey]

Hello All! I have one quick question I hope someone can help with. I have searched previous posts and not come up with a solution. It is:

Where is the fuel pump relay on a W123 280TE?

I broke down yesterday for the first time in 4 years of owning these cars. I had little warning ? a momentary loss of power whilst accelerating the day before yesterday. Then it managed to keep going on a long journey, only to break down 20 meters from my destination ? it was as if the beauty knew! The mechanic tested all the obvious things and found the fuel pump had stopped working, but worked when supplied with 12V. There are two relays by the fuse box, which appeared OK and made no difference if swapped. He noted one of the relay sockets (furthest from the fuse box) was lacking power to pin 86, and surmised that there is a broken wire somewhere, then gave me a lift home. I have tried bridging pins 30 and 87 on both relays, and even bridging 86 from one socket to 86 on the other, but that didn?t work, and I was left thinking I was playing with the wrong relays. Any suggestions welcomed. Thanks,

Nick

 

[njpumphrey]

Update

As a temporary measure I have connected the 12v feed for the fuel pump to the lighting circuit. I now have to turn the sidelights on to start the car, which is fine, but I feel like a volvo driver! If anyone can help me fix this problem permanently, it would be greatly appreciated. Thanks!

 

[TimN]

The relay can be found under the dash board on the near side. Remove the panel under the dash on the passenger side. It is held on by three screws concealed by covers which just prize off. There are also two screws down by the feet. The relay can then be found on the inside of the door piller. It can simply be lifted out

The relay has some additional electronics inside which will cut the power to the fuel pump if the engine over revs. It may look like a solid state unit but if you turn it upside down you can prize out the sealant with a small screwdriver. The lid of the relay then just prizes off.

I will almost bet that you will find a dry solder joint. Just lightly place a hot soldering iron on each joint and reheat. Then plug it back in and try it. If successful then pop the lid back on and reseal. I use bicycle puncture repair glue for this.

 

[njpumphrey]

Spot on! I found the dry joint and fixed it, and even with my clumsy soldering, it is working perfectly. Many, many thanks!