My new-to-me '95 GTB has only one cabin electronics flaw that I know about, anyway the oil temp gauge is completely inoperative. This seems like something relatively easy to diagnose and resolve, but I don't yet have a shop manual and I couldn't find a clear solution thread searching this 348/355 discussion. (I'm sure I missed one.) If anyone has the can't-miss diagnostic advice I'm looking for, I'll be much obliged.
Hi, Matt. Newbie here, too, but learning fast... As the guage has been inoperative from day 1, there are not really any clues, but the circuit is simple... sensor, wiring, instrument. Workshop Manuals can be found online here: All Ferraris From here you can find the three Workshop Manuals for the F355 in English (only). The wiring diagrams can be found in Workshop Manual #3. The wiring manuals are not overly user-friendly. Instead of identifying the components by name, they have numbers (There is a chart in the back of Workshop Manual 3 for converting the numbers to names). The wiring colour codes on the wires are based on the Italian language. I started reproducing some of the diagrams, adding some colours and tips to make things easier... e.g. http://www.iinet.net.au/[email protected]/FerrariF355Spider/Fig5InstrumentsHandbrakeABS.GIF Parts manuals will often help you to find components if the Workshop Manuals don't help. All Ferraris Some of the parts sellers also have these diagrams (e.g. Ricambi USA) so you don't have to download large manuals all at once. I haven't worked on an oil temperature problem before, but I think the temperature sensor is on the underside of the oil tank (engine bay, forward, rhs), next to the tank drain plug. Perhaps the wires on the temp sensor were disturbed/broken during an oil change? Ref Item 28... LUBRICATION SYSTEM - Ricambi America, Inc. In some references, it's called a "temp sensor", in others, a "thermistor", in others, an "oil temperature sending unit". I'll let the experts take over from here (and correct my mistakes) Cheers Ian
There is a ground wire on the oil tank . Located on inside ( in between tank and engine ) near the sensor . 8mm nut .stud is welded the tank .
Thank you Qavion and fmaderi –*hugely helpful walkthrough of the parts diagrams. Will try to get under there this weekend and see what's what. Whoever did the oil change prior to my purchase overfilled the tank and fouled the MAF, necessitating a drain+change and then a MAF cleanup. Runs like a top now, but maybe the thermistor's toast or the ground is disconnected.
Is the dash light on your oil temp gauge working? If not, it might be an indication that the gauge is simply unplugged.
when i got mine the gauge was sporadic. It was a loose connection on the gauge. Remove the two dash pod screws and jiggle the wires while it is running and see if that does it. One of the studs was loose
Makes sense. I'll pull the pod and check (two screws are in trim edge at the top, right?). Dash light on oil temp gauge working normally. Needle simply never budges - seems totally dead, not a sporadic moment to speak of.
