Citroen DS5 Relays

A no-start with a silent fuel pump, an audible click from the fuse box with nothing happening, cooling fans stuck on or off, and electrical faults that come and go. On a diesel, hard cold starting that improves once the engine is warm usually points at the glow plug relay rather than the plugs themselves — worth testing before buying four glow plugs.

The relays themselves are inexpensive parts for the common Citroen circuits. What varies is the diagnosis: several relays share the same engine bay box and look identical, so working out which one has failed is where the time goes. Ask for a quote through our form with your model and we will price the part; the workshop time is the part worth agreeing up front.

The relay coil is energising — that is the click — but the contacts are not passing enough current to pull the starter solenoid in. Before condemning the relay, check battery voltage under load and the earth straps, because a tired battery produces an identical click and is far more often the cause. Testing takes minutes and saves replacing a healthy relay.

On most C2, C3 and Xsara models it sits in the engine bay fuse and relay box under the bonnet, the unit usually referred to as the BSM. The diagram inside the lid gives the exact position for your car, which is worth checking rather than assuming — facelift models sometimes moved it a slot or two, and the relays either side of it look the same.

The quickest field test is a swap: find an identical relay of the same rating on a circuit you can live without, such as the horn, and see whether the fault follows it. If it does, you have your answer for the price of nothing. On the bench, measure the coil resistance and apply 12 volts across the trigger pins while checking continuity through the contacts — a relay that clicks but shows resistance across the contacts is the classic worn one.