355 F1 Display and Warning Lights Flickering

Time to address the latest issue with my car. When I got it, all was well except the F1 display was missing a segment, so I did a DIY repair on it with a new segment display. My soldering isn’t perfect, but I thought it went ok.

Once I reinstalled the display, all of the segments would light up for a while and then it would seem to “settle” into working normally, displaying the correct gear number. Soon after, I noticed that when starting up the car, the circled warning lights/display would remain in a flickering illuminated state (all segments illuminated and flickering on the F1 display) for a little while and then after maybe 3-10 minutes, would return to what seemed to be normal operation.

A few minutes after powering the gauges/display
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On initial power-up
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Today, I took the car for a drive and tried the Auto mode of the transmission. It worked as it’s supposed to, however, the AUTO light did not illuminate on the dash.

I had the segment display replaced by Ricambi after my attempted DIY repair, but it behaves the same as it did after my attempt. It seems that I either damaged the display circuit board during my repair or there is some kind of connection that is glitching out after reinstalling the dash. I can’t find any good wiring diagrams for any of this and I’m not sure I’d understand where to begin troubleshooting if I did find a diagram.

So, this is a semi-complicated problem that may require finding a rare/expensive replacement F1 display or maybe it can be repaired somehow. I’d appreciate any input to help me out with where to start.

What is the common element with these specific lights/F1 display and why do they behave normally once warmed up? Even after shutting the car down, they behave normally at the next startup if everything remains warm or maybe hot. That is hopefully a helpful clue. I can do more troubleshooting if anybody has any ideas. Let’s hope we can solve this one. It’s not a huge deal, but I’d like to get it solved as it’s likely a self-induced error.

By the way, the car was not running in the pictures, which is why there were other warning lights illuminated.

 

I’ll give you a call tomorrow. I’m definitely not blaming you guys because I replaced the segment display myself, which is when the problems began. My soldering skills/equipment leave something to be desired, so I very well may have screwed this up. Maybe your guy saw something specific that would be a clue as to what is going on. Weird that it seems to generally stabilize and work as designed once warmed up.

@Qavion, I’ll start digging into things in the next couple of days. Appreciate the wiring diagram. Way more than I had to go on before.

 

Looks like I’m focusing on this section of the diagram.

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I assume I fried something on the board, but I’m not sure which component that would be. Good chance I got sloppy with my soldering iron and either overheated a component or overheated some copper and “blew it out.” If I go by Occam’s razor, it’s safe to assume this is related to that F1 display PCB and something I did to it. Oops. I’ll likely end up paying a high price for my mistake, but I can deal with that. Would be cool to figure out what I did, though. If it’s a component on the board instead of the board itself, that would be fixable. I wonder if I mostly broke a copper connection on the board, but it expands enough to reconnect once things heat up. I dunno.

 

Update on this: I’ve ordered a replacement factory F1 display as I think this is simply a case of me making a mistake in soldering. Maybe I blew out a diode somewhere? I don’t plan to do any troubleshooting of the problem unless the new display doesn’t not resolve the issue.

 

Got the new display installed and all is well. No more flickering lights or odd behavior. Of course, the display I got has missing segments, so off to Ricambi it goes to get repaired correctly the first time. I’m sure somebody with time, patience, and decent electrical knowledge could fix the display that caused the flickering. That person isn’t me. I’ll stick to more mechanical repairs and leave the circuit board soldering to the experts. It is tempting to at least try to diagnose the bad board by testing and comparing each component with the known good board. Maybe someday.

 

Last update on this. I sent the “new” display to Ricambi to have a new segment display soldered on. Got it back, installed it, and everything works and looks like new. Not much left to do on the car other than enjoy it and service it regularly. I already have nearly everything I need for a thorough annual service when the time comes. I love this car! I’m oddly looking forward to the engine out in the next couple of years.