512tr starting

on those occasions when the car won't start, is there any sound at all when you turn the key or is it just dead quiet with no signs of anything doing anything? if the relay is easily accessible I imagine it wouldn't be too difficult checking with a voltmeter to see if it's the relay or something else causing the problem (with it being intermittent I wouldn't be surprised to find that something else is causing the problem, a relay is a relatively simple device after all)

 

I've just been through the same thing with my 512TR. The "start" wire from the ignition switch enters the fusebox, runs around in there for who knows why and then exits to the starter solenoid. No relay. When I disconnected the in and out wires from the fusebox and joined them together with a jumper wire, the starter worked perfectly, but I had no lights, AC, turn signals, horn, etc. I think the purpose of the starter wire entering the fusebox is to ground these circuits while trying to start the car (my amateur opinion).

Sometimes the problem is an aftermarket alarm kill circuit that interrups the wire going from the ignition key to the fusebox. This can cause a drop in voltage. The car will start when cold, but when hot, the resistance increases and the small droipo in voltage may not leave enough to turn over the starter. I also seem to be losing a couple of volts through the fusebox.

I would like to install a start button also. How is yours installed? is there a relay or a fuse?

 

Michael,
Try wiggling and or disconnecting and reconnecting the 9-pin connector. The 9-pin connector is in the left rear corner of the car in the engine bay.

Tony

 

Where exactly is the 9-pin connector?

 

resistance gets high in the circuit from age, (battery to key to starter) and voltage drops to level where starter solenoid will not engage(when warm is usually worse) . the easy and solid repair is to put a relay close to(or on) the starter solenoid(30- 50 amp), so there is a 12volt source right where you need it. you can verify what i said with a volt meter if you do not believe me. any qualified Ferrari repair facility can correct issue if you feel you can not complete task yourself.

 

The connector is at the end of #7 on this diagram. 1/2 of the connector is affixed to the car, the other 1/2 is in the engine bay. The connector is high up in the engine bay and easy to reach. The connector has a ring around it that you unscrew and then it just pulls apart

Ferrari 512TR Parts : Table 125 - ELECTRIC SYSTEM

 

Because of the hard hot start problem, I did install a relay as you suggested at the starter solenoid and it worked perfectly for the last 35,000 miles. Unfortunately some voltage bled into the circuit (I suspect inside the fuse box), causing the relay to trip and leaving the starter engaged, thus frying the starter. I would prefer to run a push button as an adjunct to the original wiring. If I run a 12v source in the glovebox to the button and then out to starter, should I use a relay and can I run it to the white wire that exits the fuse box and goes to the starter solenoid, or will this result in some feedbck through the circuit board? Should I run the relay output directly to the starter solenoid, or will this produce dangerous feedback through the original circuit?

Fried starter:
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