New alt & VR and sill won't charge-Why?

[klpete45]

On a recent trip, the alternator quit charging and the battery went dead. I was towed into a small town, charged the battery and replaced the alt and VR (did it myself). None of the gages worked (except of course the speedo) and the red light in the voltage gage stayed on, but I got back home. Apparently that was not the real problem. In-car tests at Autozone confirm my own tests that the system isn't charging. Removed the alt and VR and had them tested separatly at AZ. Both work fine. I tested the wiring from the alt to the VR for continuity and that seems ok. I tested the fusible links (under the 2 covers on the VR bracket) for continuity and they seem ok also. All fuses in the fuse block insides are ok, and the block itself has power at all stations. I've looked under the dash (difficult!!) and I don't see any obvious burnt or loose wires. The car starts and runs fine, but won't charge and instruments don't work. HELP, what else could be wrong here?:stupid:

[gema]

Get an Exorcist...it sounds possessed.

[mdbrandy]

What year Z? I just lost all my dash guages on my 1978 280Z the other day, and it turned out to be a fusible link. The link looked fine, and if I continuity tested it, it was fine - sometimes. Wiggle it around and it cut on and off. It was the big brown one in the forward fusible link block if you have a late 280. Otherwise, be sure those fusible links really are good. I got new ones from Chloe at MidwestZ, and all has been good since.

Good luck.

[klpete45]

Mark, good question, its a 1976 model. So you think perhaps the fusible link maybe sufficient to pass a continuity test, but not to conduct a substantal current load? Sounds possible, I'll try to think of some way to test them under load. Could I temperarily substitute one of the others to see if that might be the case? What would be the consequences if I shorted across the link with a wired-up 30amp fuse? Thanks, Ken

[mdbrandy]

Mine showed continuity in some configurations, and infinite resistance in others. I assume you pulled it and tested it off the car, so you changed the configuration by doing that. It might be broken when you bent it back to put it back on.

It is my understanding that the fusible links are like very slow fuses - allow a lot of current for longer than a fuse. So, I would assume that shorting a 30 amp fuse across the terminals would be at least as safe as having the link there, since it would blow faster than the link. However, it might also blow too easily; I'm not sure.

Getting known good continuity across those terminal should allow the guages to come back up at the acc ignition position even before starting, though. When mine was bad, all the guages were dead. Normally, things like the gas guage would register at acc even with the car engine off.

[klpete45]

Only one of my fusible link boxes is labeled. The one closest to to battery is labaled IGN and H.L. What are the other two links? I built a jumper with spade connectors and a 20 amp fuse and replaced each link in turn. My gages still didn't work. How about wiring to the switch? any possible connection there?

[mdbrandy]

Hmm. The one I had trouble with was in the block closest to the radiator, and was the link closest to the fender. It is marked ACC and IGN. What I don't know is if the circuits in a 1976 car are similar enough to those in my 1978 car to make my experience applicable. Things like the fact that my VR is integral to the alternator, and probably other changes might make my car different enough for it not to act the same.

Guess I'm out of ideas. Sorry.

[zebra9]

i had the same probs in my 78 280 and it was the links in the dash. i didnt replace them a electrical mechanic did, he told me that that there was 3 links in the dash.

[TomoHawk]

There aren't supposed to be any fusible links inside the car anywhere. Just fuses in the fuse panel.

[Black Jaguar]

I bought a new alternator recently as well and there are two hookups for coords that have to be connected correctly to a switch or just connected together for the system to recharge. I used a but connector and the special hookup found at autozone and the system charges fine, with out it, the system will not charge. IT is a safety device designed to run to a possalbe cord so if anyone steals the car without knowing that you need to flip this switch to charge the battery, the car dies and they cant take the car anywhere. Just my 2cents I thought I should let you know.

Dean

[klpete45]

Thanks,turns out it was the ignition relay under the dash. I didn't even know there was such a thing until it was replaced. Thanks for everyone's input. Ken