Clock resets every time I start the car ('88 3.2)

Mine (87 coupe) doesn't do it every time, but it will do the reset thing too. Sometimes it happens on start up. Sometimes it's fine during startup but resets during the drive itself. Haven't been able to identify a pattern for what triggers it. My guess is that it is probably fuse box or wiring harness related, as I do have a few other miscellaneous electrical oddities. That's all on my "to-do" list though.

 

The AR (light blue - red) wire in the k connector position 2 is what supplies always +12V power to the clock so it keeps its memory when the key is "off" (it also supplies +12V power to a bunch of other stuff, too):

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It's natural for the battery voltage to droop down to about 10.5V during starting, and you may just have an internal problem inside the clock itself, but it wouldn't hurt to unplug the k connector and see if the female position 2 terminal is in good shape (i.e., clean with two prongs touching), the position 2 male tab on the fuse-relay panel is clean (or clean it), and plug the k connector back in to "wipe" the connection. Ideally, you'd like to measure the voltage on the AR wire at the clock itself during starting:

If the voltage on the AR wire at the clock (relative to the N, black, wire at the clock) droops down to ~10.5V during starting and the clock resets = most likely indicates a problem with the clock itself.

If the voltage on the AR wire at the clock (relative to the N, black, wire at the clock) droops down a lot more below that during starting = most likely a problem with the fuse-relay panel, the wiring, or a connection somewhere.

Good Hunting!

 

But you miss a point- the clock is right twice a day !!!!!

 

My driver's side door lock switch does not work. But the lock itself does. I can use the passenger side switch to open both door locks. Also, my fuel filler door and glove box door switches used to operate intermittently. But lately, I cannot get either one to operate via switch. Sometimes pressing and holding the switch 200 times in a row gets one or the other to "pop" open!

 

Take the door switches out and try on the bench with power

 

I just sprayed contact cleaner around my switches without even removing them, both work a treat now.

 

Ben - I suppose you have a US version: Just a thought - the clock receives permanent 12V via a deviation at the "ignition key not removed" switch attached to the ignition key:

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If there was a problem with the mechanical/electrical integrity of that microswitch while you spring-load the key to start the car and it could momentarily cut 12V to the clock.

 

Oh just saw your post! Good

 

Yeah, I may give this a try. Can't hurt!

 

Great tips

 

Ok so just realized the clock on my 84 only resets if I use the headlight toggle switch. No idea how this ties into the clock but it's obviously a short... Not sure what part to replace

 

Now this is super interesting as I'm chasing a "permanent 12V to oil pressure gauge" issue on my '88 3.2: the oil pressure gauge doesn't light up until the 1st time I turn the engine on after connecting the battery, and doesn't turn off unless I disconnect & reconnect the battery.

All new relays so it isn't anything "stuck" but some kind of loop in the wiring. New relay board from GT Car Parts so it isn't a short.

Good to know about this clock circuit.

Where can I see the rest of this schematic? I'm working from WSMs from 88 328 and 87 3.2 and obviously I'm looking at the wrong diagrams 'cause I've traced EVERY wire on those and not found the root cause.

 

This link will get you the 488/87 wiring diagram for euro and Swiss Mondial 3.2. The injection system diagrams won't match a US version Mondial 3.2, but I think a lot of the rest will be the same:

https://www.dropbox.com/s/2flk2dj2g8an7ir/Mondial%203.2%20Wiring%20488_87%20by%20Urs.pdf?dl=0

 

Send me a PM for a colored version. It helps reading things

 

Send me a PM for a colored version of the wiring diagram of your car - Euro or US version.

The clock has 4 wires - ground, permanent 12V, ignition on 12V for the bright LED output, 12V lights "ON" input for the dimmed LED output. It looks like your clock's dimmed function is dead. You could test that easily by cutting the grey wire to the clock. It should then stay on bright regardless of the light switch position, but might be a bit bright for night driving.

 

low pressure light or needle, or both? What happens when you switch the ignition on? No red light? What happens when you start your engine? What happens when you switch your engine off? Ignition OFF?

All 4 instruments receive, via a common plug, ignition ON 12V via the same wire, have 1 ground wire for all and 1 illumination wire serving all 4.
So, if the other instruments are working normally that wiring is essentially working. Both the warning light and the needle movements are controlled by negative inputs, not 12V.

I would check if your oil pres gauge is wired in correctly, like the other instruments.

 

Also noteworthy, I can trick the clock to not reset by doing one simple sequence.

When it's time to turn headlights off, just wait until you're parked and shutting off ignition key. Voila, with no power on you can then turn the knob off. This is easy to practice, and vice versa it's safe to put lights on it's just the turn off feature where you gotta think first hehe