Restoring 1974 914 1.8 liter L Jetronic. No starter response to ignition switch. Replaced original starter - no luck. Installed Bosch Starter Relay Hot Start Kit - No luck. Cleaned ground connections to transmission ground strap - no luck. Any suggestions?

If not obvious, I am like a monkey with a iPhone when it comes to auto electronics.

Does the starter turn when you short the solenoid positive to the starter positive with an insulated screwdriver? If so, you know the starter is good.

If not, does it do it out of the car with jumper cables? If so, then you have a wiring/switch problem. If not, you have a bad starter.

Some deftness with a multi-meter (and a friend to work the starter switch) would help in all this.

see if you are getting 12v to the yellow lead with the key engaged to the start position. If not check the ignition switch and the interlock relay under the pass seat. If so then check the transmission ground strap and the positive cable connected to the battery and the starter

A 74? Look under the passenger's seat. There is probably a box plugged in under there with "LOGIC RELAIS" on it. That is the Dreaded Seatbelt Interlock Relay.

Unplug it, and give it the "float test". (Throw it into the lake; if it floats then save it for further study.) Then plug the two large yellow or yellow/red wires that go to the socket together.

If the starter then works, remove the temporary plug and permanently attach the two wires together. Either a butt splice or solder them and cover with at least one layer of shrink tubing.

--DD

Cracked ignition switch is one of the most common causes of this. The old screwdriver trick at the starter could answer a lot in 30 seconds. Always test things before throwing parts at it. It's rarely the starter.

Been watching this thread as i somehow killed mine between cleaning the underside of the motor (to try and find an oil leak) and doing some wiring of a gauge (through the tunnel) My car is modified with carbs and the wiring has been redone underneath - basically all of the wires running to the starter are "RED" - I am going to check the solution under the seat...i already replaced the relay and i have a new ground strap.

Does anyone have a wiring diagram / schematic on where the different leads are going, etc...just trying to trace it all back and understand where everything goes...any help or guidance is appreciated.

I ran the car for quite some time to "dry it" after cleaning and i had no issues...next day it wouldn't start...starter doesn't turn at all

Thanks

Attached is what the setup looks like - Relay is under the car, which seems odd to me...Click to view attachment Click to view attachmentClick to view attachmentClick to view attachment

Oh wow, yeah...that's pretty odd. The yellow lead should plug right into the starter like so:


The terminal on the starter is the solenoid terminal and acts as a relay of sorts already, that external relay is just adding an extra point of failure. Some definite Department of Redundancy Department stuff going on right there, unless, somehow, the yellow wire is so high resistance that it can't properly trigger the solenoid in the starter, but can trigger the relay coil. (The wire comes from the key switch, to the under-seat relay, to the engine bay relay board, and then finally to the starter solenoid.)

My guess would be that water got into that relay. I'd try pulling the yellow wire's spade connector out of that relay, and hooking it into the spade connector on the starter and see if it starts with the wire hooked up there instead.

Unless I'm mis-seeing something...the ring terminals are on wrong. The photos aren't awesome so I don't want to make a specific recommendation...but here's how the terminals should be on the relay:

Pin 86 - ignition switch
Pin 85 - ground
Pin 30 - battery
Pin 87 - starter solenoid power

The large ring terminal from the battery should be attached to the starter power lug, which is typically the one with the large wire going into the starter itself (the starter grounds on the transaxle case; looks like you have nothing connected to that lug).

Bad wiring job, using same color wires. Plus, no circuit fuse protection and could have been done much cleaner. Buy one of these that uses the colored wires, or find the thread where Mark uses a Ford starter solenoid:

https://www.pelicanparts.com/More_Info/WR1.htm

The starter spins when jumped but does not crank engine. Attached is a picture of starter connections.Click to view attachment

The Seatbelt Interlock was disabled many years ago.

Is there a way to test the starter switch without pulling it out of the steering column?

The spade terminal, when energized, pulls up the solenoid and engages the "bendix". When it is fully pulled up, the bendix connects power between the two big lugs on the solenoid, allowing the starter to spin.

For a functional starter to engage and spin the engine, power has to be put to both the solenoid lug and to the spade terminal.

To test the starter, you can jump across the terminal where the battery wire is connected to the yellow wire spade. If that is only spinning the starter but not engaging the flywheel then you likely have a bad solenoid (or, less likely a bad solenoid gear and/or flywheel, both of which can be inspected with the starter removed).

If you just jump across the big lug terminals then the starter will not engage the flywheel and will only spin.

Get a voltmeter or a test light and connect it to the yellow wire under the passenger seat where the seatbelt interlock used to be. Then when you try to crank the engine with the key you should see 12 volts at the yellow wire.
If you have 12 volts there you can also do this same test through the rest of the starter circuit.
Go to the yellow wire coming in to the engine compartment relay panel, pin 1 on the 14 pin connector.
Then next is the yellow wire exiting the relay panel, pin 6 on the 12 pin connector.
The the last check is the yellow wire at the starter.

If the switch is bad you won't see voltage at the first test point under the seat.
Jim