Hello , I have my 1975 914 won't crank with the key. But will start with screw driver to starter , I can hear a click under dash above fuse panel when I turn the key , any ideas?Click to view attachment

Many years ago, our 74 had similar symptoms and I ended up adding a starter relay. My guess is the root cause is a poor ground, but may be something else on the positive side of circuitry. There are many experts here, and it'll be great to hear other's experience with this.

I'd use a voltmeter to see how many volts are actually present at the starter's solenoid when the ignition switch is held in the starting position. You'll either need an assistant or some long meter leads to do this obviously. I'd also try different grounding points for the meter.... close to the starter and up in the cabin. I remember vaguely (many years ago) mine was low, maybe around 9 or 10 volts, so the quick fix was to have the wire from the switch energize a relay and the relay would pass voltage from the battery lead to the solenoid engagement lead, like shorting with a screwdriver, except controlled via a relay.

Just so you know, our 914 has sat for close to 15 years under a carport. I've just recently found this forum after starting to think about getting her running again. There's some amazing talent shown by the experts here, and it's really motivating to read other's rebuild posts. One of the many (hundreds) of things we need to do includes finding the root cause to the problem you're addressing. It wouldn't surprise me for someone to post the exact cause and a solution.

Dan

Noise at fuse block is odd.
Unscrew and pull down the fuse block and look at the connectors, make sure they're all connected. While you're in there clean the fuse block ground, upper left above the block.
Not sure on a 75 but check to see if there's a white plug in behind the key area.
Start cleaning all your grounds.

You could try getting another ignition switch. Very simple to pull the plug off the old one from behind and plug it into the new one. Use a screw driver in the new one to test out. If it works, you have a bad ignition switch and you will need to pull the steering column apart to replace it.

Oh, I forgot about the seat belt relay. Think it started in 74, but the lead from the starter switch passes through the seat belt relay so you couldn't start the car without seat belts on. Mine's bypassed, but you may want to check this out also. There's wiring diagrams in many manuals, including those you can download for free. It could be this relay or a lead to it that has an issue.

Dan

Yep; I disconnected mine 40+ years ago for the same reason. Connection is under the seat.

There is a small chassis ground wire on the SB relay assem. If the wire is not connected to the chassis, the starter will not function.

And where exactly is that? Which wire is it and where is it grounded? I am having some problems with this rats nest SB interlock relay thing