That might be a tricky one as you have mirror heat and rear window heat. I have a Spider, so I don't know where the disconnect point 40204 is for the rear window. Hope it's a cheap fix. I guess it's not a shorted lamp in the binnacle as I think you said the fuse was still blowing with the instrument panel disconnected. I believe there's an easy way of removing the glass from the mirrors, but I haven't done that personally. The door plugs are not too hard to disconnect for isolation purposes, as long as you have enough room to open the doors wide.
@Qavion Do you have wiring diagrams for '99 355 F1 Spyder? Specifically for the engine/transmission. I am trying to chase down an intermittent issue with speedometer and gear shift cutting out. Sensor on trans tested good, but need wiring diagrams to move further. Thanks
Speedometer will not register while moving, and car will not shift up the gears. Moves normal in 1st and reverse.
I have no specific diagrams for 99 cars’, but I doubt there will be differences regarding the speedometer system on these cars. The speed sensor sends data to the instrument panel where it is processed in the speedo. For F1 and engine use, the raw speed data is divided by two by the indicator and sent to the F1 TCU and Motronic ECU on splices. If the speedo is not working, then it’s probably the sensor or wiring or perhaps, a loose connection on the back of the speedo. Having said that, there was a case of the tooth on the gears breaking off. A rather expensive fix. Anyway, I’ll post the Instrument diagram shortly. How did you check the gearbox speed sensor? The wiring is not found for that in any documentation I’ve seen.
The way the system works is the right wheel speed signal is used to calculate (either by the ABS unit or the ECU, I can't remember which) the vehicle speed which is then made available on the CAN bus for anyone to see/use/display. If the speed is intermittently missing, the Transmission Control Unit would likely not allow you to shift for safety reasons.
Speed sensor was replaced when the issue first showed itself. Read it was a common failure point associated with symptoms. It initially resolved the issue, but then started having the same symptoms intermittently. Hooked up a scope, and spun the wheels to make sure sensor showed wave form. Believe problem is a break/poor connection in the wiring, but have no diagram to verify continuity (or lack there of)
https://www.dropbox.com/t/mvynfNSW3JwV7tmU Image Unavailable, Please Login I was wrong about the loose connection on the back of the instrument. I must have been thinking of the other instruments with nuts on the back.
Sorry, I thought you were referring to the gearbox speed sensor under the gearbox, not the speedo sensor on the side of the gearbox. The wiring has been known to be damaged on the speed sensor under the gearbox (also), but that wouldn't affect the speedo. See Item 81 for other "speed" sensor. https://www.eurospares.co.uk/Ferrari/355/355_(5.2_Motronic)/PartDiagrams/031/Gearbox_Covers_and_Lubrication
The speedometer wiring goes through plug 41024 if you want to break the wiring into smaller chunks. Image Unavailable, Please Login LHD car shown (not sure where you're from).
Hey Qavion can you please post the link of the wiring again I have te same trouble with the Indicators :-( thx Henrik
This might help. https://www.dropbox.com/t/Ph6KysMeMu8yUIbr The diagram contains a graphic showing the pin assignment on the Hazard/Turn Module (Relay).
If you're an owner, don't forget to fill out your profile on FChat. I don't always remember who has what car
@Qavion Could you kindly please share engine diagram, my car the engine will crank but won't start. Tried replaced crankshaft sensors and camshaft sensors. So we believe is the wiring because its not firing. I have 5.2 Manual Euro or US spec either should do. Thank you very much.
You'll need two diagrams at least... I think these are the closest to your spec https://www.dropbox.com/t/jlYUxemVONcu1om0 https://www.dropbox.com/t/E4ST43VWcN3NTREK Is the immobiliser unlocking the Motronic ECU, allowing you to scan for codes? Links expire in 6 days
There's only one of each sensor on the 5.2. Just a slip of the tongue? Are you getting spark when cranking the engine?
