I have ‘73 914 2L with factory FI. My fuel pump fuse all of a sudden started to blow.
I checked my AAR and it functions as it should. I checked the lead and is does not appear to be compromised . I checked the resistance and it is reading 13. What else do I need to check?

Best solution is to disconnect the cars wiring to the pump and run independant supply to battery and test that way then you know the pump is ok.
Have you tried another relay for a proven working one from elsewhere on the car ?,removing a headlight one is simply,good luck.

If you have a battery charger run the pump off of it and see how much current it pulls. I think it should be around 5 amps. If it is ok check for shorts to ground. Swap the relay with a headlight relay. Make sure all connections are corrosion free.

Kind of a long shot but mine kept blowing because I hooked up my engine blower motor up backwards. Apparently it did matter the plus and the minus. They use the same fuse. I pulled up on the heater lever in the car and the engine quit!

Just spit balling. Hope you get it solved

Resistance should be around 1.5-8 to maybe 4.0 eprox.(old one). There will be variations but 13. is probably close to cooked.