S1 melting fuel pump relays
Discussion
It's not normal for them to get that hot, but there are some common faults that are worth checking for.
First check the relay socket terminals are clean and tight. They can relax with age and also corrode - and both these problems get worse when it gets hot, so you can have a vicious spiral. Also check that the solenoid supply is sound. If it's browning out or failing intermittently you might not notice it but the clamping load on the contacts will be reduced which is going to introduce contact resistance and heat.
First check the relay socket terminals are clean and tight. They can relax with age and also corrode - and both these problems get worse when it gets hot, so you can have a vicious spiral. Also check that the solenoid supply is sound. If it's browning out or failing intermittently you might not notice it but the clamping load on the contacts will be reduced which is going to introduce contact resistance and heat.
Your S1 may be different but on my S3 there is a wiring connector between where the wiring comes out of the body and the fuel pump, right by the rear wheel. Any corrosion here ( or anywhere else ) will increase resistance causing a rise in amps which in turn overloads relays, switches etc.
If its getting hot, I would suspect the following
1. There should be good connections to the relay,loose connections will get hot, not only due to the way a poor connection acts on the joint itself but also because on the relay a poor connection may be constantly bringing the relay "in and out", this will cause it to overheat.
2. The fuel pump is taking more current than it should, replace it before it goes.
1. There should be good connections to the relay,loose connections will get hot, not only due to the way a poor connection acts on the joint itself but also because on the relay a poor connection may be constantly bringing the relay "in and out", this will cause it to overheat.
2. The fuel pump is taking more current than it should, replace it before it goes.
What causes the relay to overheat is the supply to the coil being intermittent. The coil inductance has to dissipate a lot more power if the supply is not perfect DC.
If the fuel pump is the problem then it is just the relay contacts that may heat up a little.
Primary areas to check are corroded or loose connectors in the fuse box and the internal connections in the fuel pump relay.
Disassemble the fuel pump relay and you will find that the connector pins are soldered to a printed circuit board (containing electonics and a small relay).
The soldered joints between the pins and the PCB are notoriously fragile and need resoldering properly. You can also re-tin the connector pins with solder at the same time which solves most problems of loose connectors in the fuse box.
If the fuel pump is the problem then it is just the relay contacts that may heat up a little.
Primary areas to check are corroded or loose connectors in the fuse box and the internal connections in the fuel pump relay.
Disassemble the fuel pump relay and you will find that the connector pins are soldered to a printed circuit board (containing electonics and a small relay).
The soldered joints between the pins and the PCB are notoriously fragile and need resoldering properly. You can also re-tin the connector pins with solder at the same time which solves most problems of loose connectors in the fuse box.
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