Year 87
Model tubro II

the clock seems to work when it feels like. some times its really dim some times its gone entirely and sometimes its bright as day. any thoughts on this?

 

Very common, so common it seems like a designed mode of operation.
It's solder point failure, the module needs removing and resoldering.

 

Very common, and clokker is correct.

My clock works about as common as an albino deer sighting in downtown Dallas.

 

I have actually seen Jackrabbits in Downtown Dallas before.

 

Did they have working clocks?

 

Why in fact one particularly vocal one kept saying he was late, and he DID have a pocket-watch.

 

 

Not to point out the obvious, but I believe this info is in the FAQ.

 

There's no symptoms listed other than "not working" rather than odd functionality. Thus why I'm asking

I hate soldering things.

 

Then leave it to someone who has experince for you have to desolder first then resolder. The item being worked upon is rather sensitive to heat so the soldering tool needs to be able to operate at the correct temperature range.

 

There are two distinct failure modes, the clock itself and/or the lighting.
Is the clock correct when it flashes back on? If so, the lighting is at fault and that's not surprising because Mazda was in love with overly complex whizbangs in the electrical system. Supposedly, the clock illumination is bright during the day and then dims when the running/head lights come on.

Usually, when my clock deigns to make an appearance, the time is still correct, which means the clock is fine and has not lost power and reset to 1:00. It's the lighting that's messed up and it will flicker between bright and dim until it gives up and goes dark again. Sometimes, flicking the lights on will resurrect the clock but lately, not so much.

Were I less lazy (and didn't already plan a completely different solution) I'd sort through the schematic and find the wire that comes from the gauge cluster lighting (tells the clock whether it's "dark" or not) and disable it.
I'm thinking this would bypass the "switching" function in the clock illumination circuit and maybe it'd work consistently (albeit consistently bright, as well).
This is just a theory so far though and I haven't tried it.

The reason I haven't gone further (besides the aforementioned sloth) is that of late, the clock itself has started acting stupid.

It used to really irk me (which is why I spent so much time working on my alternative plan) because the clock was my bellweather for the car's health...if the clock worked, everything probably worked and I was reassured.
My flickering clock just reminds me the the ravages of time are accreting, my best efforts be damned.