360 Wont start?

Small correction: The relay deactivates to remove power from specific systems during start. Here's a short technical description. The relay is numbered 92, but varies from vehicle to vehicle.

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Shown in this photo:


For future reference, note that my wiring diagrams show the relative positions of the relays (looking towards the rear of the car). This is the "5H" block on newer cars:

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The earlier cars have different numbering:

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Note that the numbers are mentioned in the Owners Handbook

Don't worry, I'm just as confused as you are at this point. We have to figure out what "resistance/load" we are measuring the voltage on. If there are multiple components in series or parallel, we have to make sure we are measuring voltage at the right points. Let me recheck the circuits and see what I can come up with.

 

So, because your first test was carried out with the starter (small) plug disconnected and ignition on, you are measuring the voltage across the coil of relay 92.

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I would say your first voltage checks were normal. I forgot about relay 92's affect.

With the starter plug connected and your pigtail being used, you are measuring the voltage drop across the starter solenoid (to earth). i.e. small plug disconnected and ohmmeter on starter terminal.

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The voltage will vary according to the relative resistances of the coil of relay 92 and the starter solenoid.

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If you got zero volts in your second test (starter lead connected and ignition on), this suggests to me a shorted starter solenoid (or at least a very low resistance).

Can you remove the starter lead and measure the resistance of the starter solenoid (i.e. terminal to a good earth).

 

When you felt the starter relay click when you turned on your ignition, could it be possible that it wasn't the starter relay, but relay 92 next to it?

The fact that your starter didn't turn when you jumped your leads on the starter suggests to me that either the starter is faulty or you don't have enough volts to turn over the starter.

EDIT: however, that contradicts your bench tests

 

What power source were you using during your bench tests? The car's battery?

 

Have you had thus car on a scan tool yet? What is the F1 hydraulic system pressure?

If it is too low..the car will not start no matter what you do.

Secondly..are you absoulty sure the immobilizer is deactivated.. I have seen these units beep at they should..light goes solid..but the car is still immobilized..

You need to scan this car.

 

The tcu will cut power to the starter relay if low pressure is detected. Stop wasting time. Have the car scanned. You are peeing in the wind at this point.

 

His starter relay is clicking, Tom. The F1 TCU is sending out a start signal.

 

I have never replaced a starter on a 360 or 430..ever. Not to say this couldn't be a first..

 

You have all kinds of interesting/unusual things going on here. Note that relay 92 cannot click/operate with the start relay removed. When you say it got power for a second, is that literally? It stopped supplying a voltage after a second? Anyway, you could try swapping it with the windscreen wiper relay to see if that helps.

Regarding your photo... and the measurement of the solenoid resistance.

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I assume the black wire isn't shorting to the case in your photo. Unfortunately, I don't have any values for the 360 starter, just what has been said previously on the forum:

https://www.ferrarichat.com/forum/posts/142488877/

Google tells me that it can be anything from 00.1 to 100 ohms (although some sites say 0.3 ohms is too high). I don't know how accurate your meter is. I assume your meter is showing ohms, not milliohms. Also, your starter works on the bench (at least under no cranking load). Also, we know you are getting volts at the starter during cranking when everything is plugged in.

Its almost as if your engine is frozen or the starter is not strong enough to turn the engine. Of course, the ability of the battery to supply cranking amps might still be an issue (despite how new the battery is).

 

For reference, I just checked the resistance on my F355 starter solenoid and the value flickered between 0.1 and 00.0. That is, from the solenoid contact to the starter case.

The results varied slightly depending on what I used as an earth (solenoid case, starter case, etc)

 

I'm always for starting with the simple stuff. Earth the body of the starter with a jump lead. Swap out the battery temporarily for a known good one.

When mine did somethign similar I undid the cover plate on the rear of the solenoid ( three bolts) The solenoid core has a spring and copper disc, this disc bridges the circular terminals passing power to the motor. Mine just needed sanding clean and smooth and has been working for ten years now.

 

Sounds like a good result, Bob. At least it wasn't something expensive in the F1 system. Was the labour $300 or both the starter and the labour?

We both have Thanks for your patience and great photos. The photos will be very useful in the future.

 

I’ve been watching to see the resolution, glad you got it figured out.

 

I just replaced my oil pressure sending unit a few weeks ago (50 miles ish) and its already failed. Hopefully this is just a fluke as well and not a new trend in parts for the 360.

 

Many of the OEM parts are just as old as the cars themselves. Age takes a toll on parts sitting on a shelf so it's likely the failure rate will only increase and spread to other, formally reliable areas.

The good news is that many of the components for these cars are made for other cars or a close twin can be adapted to fit like OEM. A good example is the siren module. The exact same model fits on a Corvette but has different firmware. One of the posters here, @gobble , updates the firmware for the Corvette one and turns it into a Ferrari one. Direct message him if you want the details.

Other parts are available from other cars, like the impossible-to-find-and-too-expensive-anyway throttle bodies for the 360. With very few tools and a lot of caution, an owner can DIY rebuild their factory units with parts from a Porsche throttle body. Another poster here (me) has an adapter to allow using the Porsche throttle bodies directly.

So lots of alternatives with more coming every year. These cars are worth keeping running and people will find a way.

 

Glad it’s resolved without too much pain.