Really hard electrical problem

[Xenn]

Hmm, I havent thought of that, i was going to pass on doing the alternator upgrade because mine looked new, but switching to the internally regulated zx alt might help.

As it is im going to swap the distributor out this weekend then hold back for awhile, I dont like to go past 2 solutions to fix a problem before it popps back up, in case I do fix it, I can help others out when they have the same problem, and not just say "replace half your car, i did and the problem went away for me."

[Xenn]

Oh, I completely forgot, there is another seemingly related set of problems.

About half the time when it dies, suddenly afterwards once its running, the turnsignals and heater blower no longer work for a few days, then will randomly start working again (hazards never stop working) Occasionally like today, it will happen on its own, (though i have noticed a few hickups).

Does anyone know off the top of their head if these two components (blower and most likely turn signal switch) share a connection or ground anywhere in the car.

I dont have time for a few days to bust out the multimeter and start testing things, and by then it will probably be working again.

[Zed Head]

You could browse the wiring diagram, or the smaller versions in the Electrical chapters.  Wiggle some wires in the meantime.  Loose connections might be the cause of all of your problems.

[Xenn]

Its working again as of this morning, I dont feel like its a lose wire, more like some component that disconnects sometimes when it gets too hot, or switches on/off then cant switch back. The turnsignal (heater may or may not be related, still unsure, havent had a squirrel cage for my blower motor again until recently.) only does this after the car has been turned off.

Yesterday for example, went to work, everything ran fine, delivered things to the post office at the end of the day and realized neither turn signals nor heater suddenly work. Still not working on the drive home. This morning getting in the car, i hit the turn signal, it clicks once, then after a second delay starts blinking on my dash and clicking/running normally, still no heater, 2 min down the road i try the heater again and it works. New turn signal capacitor, new blower motor, fusable links swapped out for breakers, no blown fuses, etc.

 

Sometimes it feels like someone has a switchboard for my cars electricals and messes with me by turning things on and off randomly. 

[Zed Head]

Seems like fun entertainment.  I've had those kinds of problems before.  They're fun until they leave you stranded somewhere.  Or you get an expensive ticket for failure to signal.

Feelings will only get you so far.  If you're lucky the final fail will be close to home.  Good luck.

 

Edited October 21, 2016 by Zed Head
Feelings

[Xenn]

+1 for Offspring.

And yeah, last time a car decided to fail on me far from home i was basically in a different state and had to scrap it instead of fix it, I think i might cry if my z did that to me. 

Its also my only car right now because of that, so i would probably lose my job if it did that. Yay poverty!

[Zed Head]

The blower and signals seem to share a fusible link.  Can't tell which one, they're not labeled in the diagram.  Probably Acc.  Check those connections.

[Xenn]

So updates:

It was still acting up, so last weekend I finally got around to upgrading the distributor. Wow the car runs better, most notably at low rpm and when cold. However it still decided to act up, yesterday i decided to finally put the other ECU in, i was hesitant because it was from an older car that had its battery hooked up backwards once, but when i ripped it out it turned out to be nissan remanufactured (who knows from when) I stuck it in and it works great, seems to run the engine differently than the original ECU which is odd, but its improvements rather than faults, i have plans to replace the alternator soon but will wait to see what the new ECU does first.

As for the heater it seems to be its own issue thst just has bad timing, i kind of think its the temp sensor in the blower housing it sits in going. Turn signals I am unsure, its too rare to diagnose, and too inspecific, someone needs to stop feeding my car after midnight.

[Xenn]

Also looking into it, the 78z had an internally regulated alt the same as the zx, ill have to check if mine does or not before i bother swapping it as its an early 78.

[Zed Head]

Your in-dash voltmeter can tell you quite a bit about the electrical system.  Look at the needle before starting the car, at idle, and when the engine is revved up.  It should be higher when the engine is running.  And look at the red charge light.  It should be on when the key is On, and go off when the engine starts.

[Xenn]

I use my voltmeter as much as i can, and probably more than oil pressure (which is good to watch since my car slowly burns oil) , i know its position when charging so well i can tell if eqipment is on and how strong the draw is at a glance, one thing i have noticed is a slight draw when the engine wont run, which also points me to electrical, but I have also basically ruled out fuel and air as culprits. However it has ran "fingers crossed" flawless since the new ECU, but the weather has also been nice, so i get to wait till the next storm before i can tell if my car wants to die again.

[Mikes Z car]

I don't know if this idea would be of any use but I had an intermittent with my radio cutting on/off so I connected an analog voltmeter between ground and the radio circuit that I was having trouble with.  I used wires with alligator clips on both ends.  Then I propped up the voltmeter on the passenger floor so I could see it from the driver's seat.