Path from ig switch to starter

Hi Folks,

I am trouble shooting a no start problem on an 86-328. The starter did not turn at all (it didn't crank the engine) when the ignition switch was engaged.

Below is a photo of the back of the ignition switch. Which pole carries a control signal to activate the starter?

I also want to bypass the switch and provide this "control signal" directly to the starter to make sure the starter is functional. From the starter photo, is it the brown or white wire that I need to provide a 12v (for starting signal and NOT main power) to? What's the yellow and green stripe wire for?

Lastly, is there a fuse (or relay or solenoid) involving the starter in the fuse panel photo below?

A great many thanks!

Nguyen
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The ignition switch puts +12V on the white wires (terminal 50) when the key is in Pos III (start).

Can you try reposting the photos (looks like one is incomplete). In the stock 328 system, there is no relay and/or fuse between terminal 50 on the ignition switch and terminal 50 on the starter solenoid. There are some connectors in the white wire path that can be troublesome in the passenger footwell (135) and the engine bay (169). The GV (yellow-green) wire might be from the alternator D+ terminal (that goes to one side of the alternator warning light bulb in the dash).

Have you downloaded a copy of the '86-'87 328 wiring diagram from www.ferraridatabase.com?

What version 328? euro, US, CH?

 

Hi Steve,

It's an 86 US version. I just downloaded the schematic, many thanks. What's the number in front (eg: 2.5 B, 30 N, ...) of the color coded mean? Now I just need to find those trouble some connectors in the path. Pictures are reuploaded.

Many thanks again,
Nguyen
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The number (2.5, 30, etc.) is the cross-sectional area of the wire conductor in mm^2. Those wires without a number are 1.0 mm^2 in size.

The letter is the wire insulation color (in Italiano). E.g., B = blanco = white, GV = giallo-verde = yellow-green, etc..

The 169 connector is just forward of the LH rear Koni as shown in this jpeg (it's the larger one):

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The 135 connector is behind the passenger footrest panel.

Your 328 uses the same stater motor & starter solenoid as the TR, and we've had many reports of bad TR starter solenoids (but the usual symptom there has been cold start = OK; warm start = nothing -- so your symptom seems a little different). If you do a search on "TR WAI solenoid" (here and at the old site) you should get a lot of prior discussion.

My advice would be to unplug/inspect/clean, if necessary/reseat the 169 connector. Then measure the voltage on the white wire there (you should be able to touch the probe from your multimeter to the metal terminal while everything is plugged in) to ground while an assistant turns the key to "start":

If the voltage on the white wire = about 9V, or more, when the key is in Pos III (but no starter solenoid motion occurs), then either the solenoid is bad, or maybe the white wire connection to the solenoid is bad.

If the voltage on the white wire = 0V, or just a few volts, when the key is in Pos III, then go after the 135 connector and make the same sort of test there.

The 169 connector is fairly accessible, and, from this test, you'll know whether to look upstream or downstream from there.