Electrical Problems , Please Help!

[killerpoon]

Ok so my car is a 76 280z and the car isnt charging the battery it doesnt seem i replaced the alternator already , i did backyard trouble shooting by removing one of the terminals and the car died , only problem is - it continued to dod the same thing after i replaced the battery . but once i turned it on with the new alternator all the lights in the car including the lights in the stereo went out . but the car continued to run . i cut it off after noticing that the rpms were slowly but steadily rising at idle to about 1800-2k rpms i did not replace the external voltage regulator and the battery is fairly new . after the cars been jumped i forgot to add it starts up immediately and stays running but once you turn it off it will not turn off it will just make your typical dead battery click.

anyone know what might be going on with this thing its a lil discouraging . and does anybody know what the gauge the black fusible link is supposed to be it completely rotted away and i believe it goes to something pretty important :stupid:

thanks so much in advance by the way first post!

[IdahoKidd]

How long have you had the car? Did this happen all of a sudden or were there other battery issues? Such as continual low or repeated dead battery. Did you make ANY other repairs under the hood or in the dash before this started happening?

Check and recheck the battery cables and connections at both ends. Be sure you have a good ground to the engine and to the chasis.

Just out of curiousity, do the lights come on when the car and switch are turned off? My initial thought is that you have a bad ground with the battery cable.

Leonard

[killerpoon]

i checked the ground to the chassis and it looks fine , i just bought the car about a month ago and first thing that happened when i got it was the headlights went out and wouldnt turn back on but i was 200+ miles from home so i had to wire them straight to the battery and disconnect them when it wasnt necessary to have them on . other then that the car seemed to perfectly fine , and as of now no lights come on with the key in . ima charge up the battery and try it again and see if theres any change

[SteveJ]

1st thing: DON'T TAKE OFF THE BATTERY WITH THE CAR RUNNING.

2nd thing: Get the FSM. You can even find one to download at XenonS30.com. Then read the diagnostics on the charging system.

3rd thing: Check the alternator you put in the car. It might be internally regulated. Put a voltmeter on the battery and check the car while it's running.

4th thing: Look at your electrical system including grounds and fusible links. The car is over 30 years old. Corrosion wreaks havoc on wiring, especially in places like Florida.

[killerpoon]

i charged up the battery but the car quickly drained it , plus the interior voltmeter gauge was a wavering a decent bit before it dropped , plus i still have no interior lights whatsoever including the customer actual lights and the stereo all do not function yet i cleaned up the voltage regulator plug and i also cleaned the terminals . a suggestion on another forum was that it might be the voltage regulator needing replacing. and one of the fusible links is removed , the black one due to corrosion . anyone know the amperage for the black fusible link or what the corresponding gauge wire is.

[mlc240z]

have read that you should replace the voltage regulator when replacing the alternator.

don't know if it's a 'bad alternator will blow a regulator' thing or it's a 'if one dies, the other is sure to follow' thing.

measure the voltage at the battery with engine running after initial start, if not more than 12.5 volts with a known good alternator, i'd replace the regulator.

[IdahoKidd]

In my mind there is a connection between not having lights and the battery going dead. If I recall, and correct me Dave if I am wrong, but the amperage goes through the combi switch and on to the headlights. Those switches are famous for not working at times. I changed out one on my 77 because of no lights (they'd go out when dipped and might not return). On the fuse panel down by the passengers feet, there are fuses for each headlight and another for the interior lights. Look to see if these are blown. The headlight issue might be that simple. If not, the combi switch could be grounding out and draining the battery and giving you your voltage meter wavering. Again, be sure you have a connection from the battery ground to the engine and one from the battery to the firewall or from the firewall to the engine. It needs to be more than just a visual, loosen the fastener and retighten it. Clean it up shinny to rule out that issue. Be sure the cable is cleaned as well as the battery terminal.

[grantf]

In my mind there is a connection between not having lights and the battery going dead. If I recall, and correct me Dave if I am wrong, but the amperage goes through the combi switch and on to the headlights. Those switches are famous for not working at times. I changed out one on my 77 because of no lights (they'd go out when dipped and might not return). On the fuse panel down by the passengers feet, there are fuses for each headlight and another for the interior lights. Look to see if these are blown. The headlight issue might be that simple. If not, the combi switch could be grounding out and draining the battery and giving you your voltage meter wavering. Again, be sure you have a connection from the battery ground to the engine and one from the battery to the firewall or from the firewall to the engine. It needs to be more than just a visual, loosen the fastener and retighten it. Clean it up shinny to rule out that issue. Be sure the cable is cleaned as well as the battery terminal.

I second the combo switch being likely, my 78 had the same problem no head lights or dash lights. I carfully pulled apart the combo switch and cleaned the contacts, both work now. Be carfull not to hack to much wiring trying to figure these electrical problems out, most are simple problems to solve if you are methodical.

[killerpoon]

yeah i cleaned the grounds earlier with a wire brush , i got the same problem i even cleaned the connectors on the voltage regulator as well but i'm going to have it replaced tomorrow because like they said your suppose to change em both out , as for the combo switch can someone show me a picture of one i'm having a hard time instantly getting accustomed to wheres what in the motor bay . also as a side note the right blinker gets stuck on the on position instead of blinking when the indicators on but then at other times it'll function correctly . any possibility of it being part of the combo switch i dont think it was tied into one another when i busted open the wiring diagram but it was hard hell to read with the tiny font sizes anybody have any idea on what gauge to use in place of the black wire fusible link?

edit: could the voltage regulator being messed up explain the slow rising rpms when the cars on?

and i checked the fuses earlier on today by the way , they were all fine but all the lights are still out all over the car :/

Edited January 7, 2010 by killerpoon

[grantf]

yeah i cleaned the grounds earlier with a wire brush , i got the same problem i even cleaned the connectors on the voltage regulator as well but i'm going to have it replaced tomorrow because like they said your suppose to change em both out , as for the combo switch can someone show me a picture of one i'm having a hard time instantly getting accustomed to wheres what in the motor bay . also as a side note the right blinker gets stuck on the on position instead of blinking when the indicators on but then at other times it'll function correctly . any possibility of it being part of the combo switch i dont think it was tied into one another when i busted open the wiring diagram but it was hard hell to read with the tiny font sizes anybody have any idea on what gauge to use in place of the black wire fusible link?

edit: could the voltage regulator being messed up explain the slow rising rpms when the cars on?

and i checked the fuses earlier on today by the way , they were all fine but all the lights are still out all over the car :/

for the combo switch try: http://www.kamikazeracing.org/dl/ZTech/Rebuild_240Z_combo_switch.pdf

blinkers are on the other side of the colum. perhaps you need new flasher units, there should be 2 one for hazards and one for blinkers the blinker flasher is hard to find inside near the firewall next to the steering collum.

allso use the FSM from the xenon website the schematics under body electric are way easer to read.

The rpm problem sounds unrelated to you're electrical problem, I very well could be wrong though.

Edited January 7, 2010 by grantf

[SteveJ]

So have you verified that you purchased an alternator that IS NOT internally regulated? If it is, then you could get an overvoltage condition that could take out your lights. That is why I said to actually measure the voltage at the battery with the engine on. If you bought the alternator from a big chain parts store, they may have the wrong type alternator listed for your car. Their cross references are not always right. In 78 Nissan changed from an external voltage regulator to an internal regulator.

Don't use the voltmeter in your car to determine whether or not you have the right voltage.

[killerpoon]

it says that you need to replace the voltage regulator along with the new alternator on a sticker on the alternator so it must not be internally regulated plus it was pretty cheap (i'm doing an upgrade down the road) and i couldnt measure didly just yet , i mentioned not having a voltmeter . BUT, i am purchasing one tomorrow , today was a work today so tomorrow i pick up the new regulator , new fusible link which as someone in another forum posted -

"Black (fusible link) is 80 Amps, and connects the output of your alternator to the battery positive post, as well as the rest of the car! If yours is partially or completely melted/cooked/fried/cremated, then all the new alternators in the world can't help you."

along with purchasing the new voltmeter i'll keep everyone posted with my results . even though this isnt over i'd like to thank everyone for helping a newbie out with my personally puzzling problems . much appreciated but yeah update tomorrow!