Testing Cold Start Valve

Many thanks to both of you for your guidance here--really appreciate it!

So I did Steve's test of voltage of the #9 fuse contacts on cranking: no voltage on either contact. Next step is locating the white wire in the Y connector and testing that ...

Unrelated, but I believe I located the cause of my lighting woes -- a broken solder joint on the stalk. That should take the fuse box out of the equation for that problem; with luck the cold start issue is also located elsewhere. So my fuse box lives another day, so to speak, before I start thinking about investing in one of Guido's units.


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Thanks for the images, Guido -- very helpful.

The Y connector is a little hard to access. I'm very leery about upsetting the delicate wiring -- don't want to create additional problems. Anyway, from just eyeballing the contacts after unplugging the y plug and tugging gently on the white Y3 wire, nothing seems to be obviously awry. I'm not sure I can stick a probe in there to test the voltage on start up, though. I'm wondering if there's an accessible connector further up the food chain where I can check the voltage. On the diagram I posted, the next stop would be the C10 connector, which is for the ABS unit. Here is where the diagram doesn't help me, b/c my car is an '87 w/o ABS.

 

OK, tested the voltage at the white Y3 wire both with a test light which has a sharp point and a multimeter which has a thin probe -- no voltage (insignificant readings like 0.03 V). I can't know for sure whether the probes came into contact with the copper wire because I couldn't see anything, but I would think that if there were 12V there I would have been some reading. So I take the negative reading provisionally.

 

Yes, that makes sense. But here I need the correct wiring diagram for my car, b/c the diagram for the euro (or RoW) versions traces that wire back to the ABS connector and from there to the connector for the internal temperature control unit before going to the #50 terminal of the starter switch. I'd like to know where it does on the pre-ABS US version cars.

But maybe I could look at the connections at the starter switch and measure the voltage at the 50 terminal. I have to see if it's visible from under the dash -- or whether I have to remove the switch ...

 

I got a hold of the right wiring diagram (courtesy of Mike [2cam] on the site), and it confirms exactly what you're saying. Gven that that wire runs directly to the switch, and the switch works, it would seem to leave me with two possibilities: either there is a break in the wire or it's not properly connected to terminal #50 at the starter switch.

So to check, it seems I'll have to take apart the steering column to access the contacts on the ignition switch. Or is that connector accessible under the dash?
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Guido, your photo shows the connections directly to the starter switch, no? I don't think that the dark green insulation tube that contains the various wires on mine is detachable at the switch itself (?).

I did unplug the connector switch under the dash, looking for the white wires that run to the Y3 connector on the fusebox and the starter motor. What do you think of the two white wires braided together with black electrical tape (please see photo). There's no white wires coming from the output side (female plugs) of the white connector -- there are two red, two blue/red, two yellow, and one blue, but no white. Could one of those be the Y3 wire? That would explain why the cold start circuit isn't activated. On the other hand, accdg. to the wiring diagram there should be a white wire to the starter motor, but there isn't. One of the other wires is doing that, presumably. Maybe somebody did some rewiring, or that's how it's supposed to be?
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So I confirmed that one of those dangling wires is indeed the Y3 wire by doing a continuity test.

As you can see, they're connected to the same plug that originally was plugged into the female connector to the ignition switch. If I've kept everything straight in my diagram, it was replaced by the green (V) wire, which presumably runs to the C3 connector on the left side of the engine compartment (I haven't confirmed that, b/c I'd have to jack the car up and remove the wheelwell cover).

So I have finally identified the cause of my cold start problem. The two questions remaining are (1) can I somehow reconnect the white wires without messing with the green wire to the starter motor? (I presume wires can simply be pulled (carefully, of course) out of the white plastic connector); and (2) why would someone have disconnected those wires in the first place? Maybe they had good reason to.

I took a picture of the starter switch to check Steve's conjecture. It looks like the Oem Ferrari starter switch. I also went through the records I have for the car to see any mention of it. Unfortunately I have a gap in the records from '90-'98, so this electrical job presumably took place then. It's interesting that the previous owner had the Ferrari authorized shop look at the cold start system in Feb. 2016 when he had it in for other stuff. They said that the system checked out fine. A few months later (July '16) he brought it to another shop, which replaced the CSV, citing an "erratic spray pattern." I think that this was just low hanging fruit -- easy to replace. Even though the shop said that the system was OK, the owner brings it back a month later. Then they replaced the TTS, citing an "erratic" reading. Looks like they were just throwing parts at the problem; I doubt either of those parts were defective. Then again, I installed a new TTS myself, so I'm guilty of the same way of thinking.


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Yeah, it may be that something happened to the white wire on the other end -- maybe it got damaged when someone was doing something on the left side of the engine, and they just ran a new wire from the C3 connector to this connector under the dash.

I'm wondering if I can splice the Y3 wire to the wire now occupying its spot in the connector -- I think the green one. I wonder if I can simply I pull the green wire from the connector, and then solder the Y3 wire to its plug, and then reinsert them?

 

Dumb question probably, but how do I extract the plug from the connector (please see photos)? I had hoped that I could just pop the green wire out of the plastic connector, but the wire pulled away leaving the metal plug lodged in there. Any ideas?

Somehow I knew this would be difficult. I really don't like mangling stuff ...
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Thanks, Steve, for that tip -- I was able to pull the terminal out with no drama.

So the green wire was indeed the one; soldered it to the original starter motor wire tied to the cold start (Y3) wire -- car started right up, and a test light lights up at the CSV. Now it's like 100 deg in Chicago today, so it's not the best day for a definitive test for the cold start system, but I think I've fixed it. Sincere thanks to all guiding me through this. I learned alot in the process. I made a video of all this, which I will post here in case anyone in the future experiences a similar issue.

 

As promised, here's a link to the video:



If you got this far, an hour-long video might be a bit redundant. But it does contribute to an archive of Mondial related DIY information.

 

Yeah, that blue multimeter is basically useless (even though it was expensive); maybe it's simply too sensitive. I relied on my cheapo yellow one for the subsequent tests. ... I too am curious as to what happened with the original starter motor wire. I'm assuming that something happened in the engine compartment, maybe during an engine out service. But I won't know until the next time I remove the left-side rear wheel liner and take a look at the connections under the fender. There's a gap in my records when that "repair" probably took place. ... To be honest, I was a bit surprised that this fairly reputable shop didn't perform some simple voltage tests to isolate the problem, and simply threw parts at the problem. I don't think they were trying to gouge the PO -- the car was already getting alot of other stuff done -- but they were just kind of lazy.
Anyway, thanks to you and the others for guiding me through this! I learned alot, particularly, how to read an electrical diagram.

 

A high compliment! Actually, I learned virtually everything in the video from the people on this thread, Steve in particular.