'77 Voltmeter not working after 280zx alternator upgrade

[petrol]

Hi all-

Just dropped in a 280zx alternator in my 77 280z. Started it up and it seems to run great, except the VOLTMETER and WINDSHIELD WIPERS do not work. The voltmeter needle is just dead, and the charge light is on, very faintly. Any ideas where i should start trouble shooting?

thanx,

-g

[SteveJ]

FIRST! Did you jumper out the voltage regulator? If not, STOP! Go to Blue's website and find the write up on the 280Z to 280ZX alternator conversion. You may have had an over voltage condition.

After you make sure you have properly jumpered out the voltage regulator, download a copy of the wiring diagram. You can find one at Blue's website. The link is below. Also download the 77 FSM from XenonS30. (One side note: I used 7Zip to open the zip file for the FSM. The Windows 7 Unzipping utility does not recognize the format.) Page BE-33 in the body electrical section has the schematic of the voltmeter broken down. Check the fuse & fusible links. (Also check your hazard lights. They are on the same circuit.) The schematic for the wipers is on BE-68. Again, check the fuse first.

[grantf]

ya I hope you did not fry anything. I have a 77 that has an internal regulated alternator, but the old regulator has been disconnected and the correct wires jumped. The 77 was the last Z to have an external voltage regulator, located under the fusable link bracket.

Edited January 14, 2012 by grantf

[Zed Head]

Hi all-

Just dropped in a 280zx alternator in my 77 280z. Started it up and it seems to run great, except the VOLTMETER and WINDSHIELD WIPERS do not work. The voltmeter needle is just dead, and the charge light is on, very faintly. Any ideas where i should start trouble shooting?

thanx,

-g

Did things work right before and why did you do the alternator swap? Which swap method did you use?

The last time I had a faintly glowing Charge light, my alternator was dying and took my ignition module with it.

[petrol]

hey guys-

thanx for the replies. yes, everything was working OK electrically before, except the alternator was not charging the battery. also, sorry, i should have mentioned that I did follow Blue's directions- as close as I could, anyway, my mechanical skills are novice- there were a few things I'm unclear on. one of them being the part highlighted in pink in the attached photo (not a photo of my alternator)- on my original alternator, that part was wired back to the harness via a green wire, whereas on the 280zx alternator, that "capsule" part is wired to the alternator itself, just as in the photo attached. so, i'm confused as to what to do with the original "capsule" part that is now unattached. do i use it, or the one that came attached to my new alternator?

thanx,

-g

[SteveJ]

That is the condenser. It's a capacitor that's used to reduce electronic noise. It should be fine with how it's wired. You don't need the other one.

Go through and check the things I said earlier. If you know how to use a voltmeter, check the voltage with the car on. Take the engine up to about 2500 RPM. The voltage should be around 14.5 or so. If it's more, shut down the engine immediately and check your wiring.

When you have two systems that are fused separately at the fuse box malfunction at about the same time, it's probably a bad fusible link or an overvoltage condition.

[petrol]

Steve, thanx for the help- looks like I need to pick up a voltmeter. I'll be back with more questions, I'm sure.