280z Voltage Regulator and Turn Signal/Hazard Issues

[bmpacman]

Hey everyone,

The turn signals and hazards on my '76 280z stopped working not too long ago.

I bought new flashers today and just installed them. Turned on the car to test them and got nothing. No light flashing, no dash indication, and no sound.

Anyone know what could be the issue?

I also took the car to get the battery tested since we recently replaced the alternator and fusible link from the battery to the alternator. The guy said the battery was at 100% charge, but then he said the voltage regulator (externally regulated) is bad. Is that even possible with the battery still charging? And if it is, how can I test it to be sure?

Cheers.


- Brandon

[ggzilla]

The guy said the battery was at 100% charge, but then he said the voltage regulator (externally regulated) is bad. Is that even possible with the battery still charging?

 

yes, it is possible. Get or borrow a volt meter (multimeter) and with engine idling, measure the voltage at the battery. With engine at 1,200 RPM is should be between 13.5 to 15.5 volts. Under or over this indicates a bad regulator.

[ggzilla]

The turn signals and hazards on my '76 280z stopped working not too long ago...No light flashing, no dash indication, and no sound.

 

The cause was never the flasher units apparently since replacing it didn't help. Other potential causes are:

* Fuse is blown. Fuse cover lists which fuse is for T/S.

* One or more lamp is burnt out (front T/S, rear T/S, dash T/S light)

Instead of replacing all these parts, examine them first to see if they are bad. Only replace what is broken.

[bmpacman]

Ah, I forgot to add that I tested all of the fuses with an audible continuity test and they all checked out. Also, the driver side bulb on the outside seems to be toast. Would this be the cause of the whole system not working?

 

I'll go out and check the voltage with the engine at 1,200 rpm as you suggested.

[ggzilla]

the driver side bulb on the outside seems to be toast

That could cause the whole driver's side not to flash. But should not affect the passenger side.

 

Replace it!

[moparvwfreak]

bad turn signal switch?

[bmpacman]

Is there a way for me to test the switch? And would the hazards be affected by that?

[ggzilla]

Sure there is a way to test the switch. Measure the voltage going in, and the voltage coming out (left and right).

 

But better to start with the basics.

* Are all bulbs goods, and have all all blown bulbs been replaced?

* Do the T/S come on, but not flash?

* Is there 12V on any wire going to the T/S Flasher unit? (with T/S activate, KEY ON)

* Is there 12V on any wire going to the Hazard Flasher unit? (with Hazard switch on)

* Are the the correct part number?

 

Then depending on what you get, go to the next step. Do you have a factory service manual? It has schematics and wiring diagrams and troubleshooting pages.

 

[bmpacman]

Here's the current situation:

• The left side bulb is not lighting up so I'm assuming it's bad.
  
• There is no response whatsoever when moving the turn signal arm. No exterior light indication, no dash indication, and no sound indication.
  
• The hazard switch has no effect. No exterior response and no interior light response.
  
• The fuses were all checked with an audible continuity checker, and they're all good.
  
• I just tested a connection. I found a green wire carrying about ~11.7 volts (I don't remember exactly) going into the plastic connector and coming out.
  
• I tested the green wire at the point where it met the steering column. I heard a somewhat quiet "tick/click" noise and then noticed the brake indicator light wasn't coming on.
  
• I tested the green wire again and it is no longer reading anything.
  

Did I blow a fuse or a bulb or something? This is really stressing me out. :frantics:

[ggzilla]

Did I blow a fuse or a bulb or something?

It's probable. Check them. You said you already checked the fuses, but that you didn't check the suspect left bulb. Why not check that and if it's bad replace it? Then if the left starts flashing, you know the "system" is good even if the right side is still not flashing. Take it one step at a time.

 

Start with the bulb that is suspect. Get er done.

 

The left side bulb is not lighting up

Are the others? What you say is confusing -- "No exterior light indication" -- so how do you get the right side T/S bulbs to light up? Do they light up but not flash?

 

i'm guessing from what you have said that the T/S lights were coming on a staying on (but not flashing), then after you heard the click, they went off and stayed off. Is that correct? If so, it's probably a load issue (e.g. burnt out bulb or incorrect flasher unit). Start with the bad bulb, then continue testing.

[bmpacman]

The passenger side indicator bulb on the exterior (the one that has the yellow cover) lights up solid but doesn't blink. Driver side doesn't turn on at all.

 

I would replace the bulb but I forgot to get a replacement at the auto parts store and by the time I had the chance to leave again they were long since closed.

 

I'll be picking up a replacement bulb tomorrow.

[ggzilla]

Don't replace the bulb if it lights up! You won't solve this problem by spending money. Instead, test your parts. Trace your circuits.

 

Replace a bulb if it is burnt out.

[ggzilla]

Which flasher units do you have? The wrong ones can cause it not to flash -- i've fixed many Datsun that way. But don't run out and buy new ones, check the part number stamped on the ones you just put in.

 

For a 1976 280Z they should be:

* T/S - 25520-89976

* Hazard - 25520-89990 or 25520-89997

 

If they are the wrong ones, try the old ones again (after you replace the burned out bulbs).

[ggzilla]

Did someone replace the bulbs with LED bulbs? They have special flash requirements.

[bmpacman]

Don't replace the bulb if it lights up! You won't solve this problem by spending money. Instead, test your parts. Trace your circuits.

 

Replace a bulb if it is burnt out.

 

I would only be replacing the one that is burnt out.

 

Which flasher units do you have? The wrong ones can cause it not to flash -- i've fixed many Datsun that way. But don't run out and buy new ones, check the part number stamped on the ones you just put in.

I can't check the flashers at the moment since it's so late, but this is the one I replaced them with.

 

http://www.autozone....ier=247229_0_0_

 

I (probably foolishly) was told that the flasher for both the turn signal and hazard are the same. At least that's what the computer came up with. It seemed odd to me but I (also foolishly) hadn't checked in the factory service manual or anything. I suppose that's a lesson in stupidity for me, but I wasn't expecting to be going to the auto parts store on the way back home.

 

Did someone replace the bulbs with LED bulbs? They have special flash requirements.

The car was almost bone stock and I think even the flashers that were in there are the ones that came with the car.

[bmpacman]

Well bugger.

 

I turned the car on today, started to drive it a bit, then realized that neither the speedometer or tachometer were reading anything. Completely dead; no movement.

 

My whole instrument panel is dead and the charge warning light is on.

 

I started the car again and it started running pretty rough, kind of like how it was starting to go when the battery wasn't being charged and started to die.

[ggzilla]

Check your Fusible Links, one controls the engine (I think) and the other the rest of the car. Make sure you have 12V one each side. Or the dash (instrument panel) ground may be loose, it must be firmly screwed into the dash.

 

Once you get that problem fixed, I wrote up some Turn Signals troubleshooting. You can test the flasher unit, etc and figure out what is wrong. See it at http://datsun1200.co..._Signal_Testing

(280Z turn signals are wired the same as 1200, including 3 lamps per side, although bulb and flasher Part Numbers may differ).

[datsunaholic]

Unless it's been replaced, the speedometer is mechanical, cable driven. So it's either disconnected or the cable broke.

 

The rest of the gauges are electric, so you likely have a blown fuse or fusible link. Or your entire dash is unplugged (though the charge light wouldn't work if it was).

 

At this point I'd make sure you have proper grounds too. It's not unheard of for things like the speedometer cable or throttle cables to burn off if there isn't a proper ground between the battery, engine, and body.

[bmpacman]

I checked the fusible links and they're all good.

 

I replaced the front driver side indicator bulb and it lights up now, but the turn signals and hazards don't work still. I kind of wonder if this has something to do with the recent mishap with the instrument panel not working.

[ggzilla]

If the T/S lights come on and stay on, that indicates the Flasher unit is busted. Swap the old flasher back in and see if (with the new bulb) it now works.

 

Flasher stuck on: Bad flasher

Flasher doesn't flash: several potential causes

[bmpacman]

 

I found a blown fuse which I promptly replaced. Upon doing so, the instruments started working again!

 

I also replaced the voltage regulator and the reading is what it should be. ~13.3 volts when idling @ 800rpm, whereas before it was reading ~12.4 volts @ 800rpm idle.

 

However, the turn signals and hazard lights still do not work. I'll be looking into this further, but I wanted to share the update.

[ggzilla]

sounds great. I worked on my datsun today and got the lights working (one broken bulb and one wiring mis-connected)

[Asmilindog]

Same thing happened to me. Noticed battery not charging also. Replaced ignition relay under passenger side glove box near pull for vent. Fixed. Found then that relay malfunction probably caused by alternator going bad. Would intermittently short. New altenator at Oreillys 59 bucks. Now all good.