Secondary air pump (SAP) fuse keeps immediately blowing

[xaos]

Hi all, it seems this section is still very active. What would cause the SAP 50a fuse to keep blowing-immediately after it was replaced-when you cold start the car ? Sap pump never even turns on because the fuse keeps blowing. the pump is new, the old one was doing the same thing. TIA.

[JimLev]

Have you checked the wiring from the fuse and relay to the SAP?

[Jaaap]

- Check that the (new) pump actually works on 12V applied directly to the terminals.
- Check the wiring for a short to ground (with a multi-meter)