Hi Folks,
Well a few months back before I headed overseas once more I had a problem with the car only running while using jumper cables.

As soon as I removed the jumper cables the car simply stalled - the fitted battery was quite flat but expected that the alternator would keep everything running

Anyway I tried to test the alternator in place and didn't see any voltage increase when I fitted the battery from our other car (a Saabaru 92x) so then looked at the 75A fuse and all looked OK so assumed the alternator was goosed

Tonight I was looking to source a replacement alternator online and happened to notice that Advance Auto Parts do free checks of the alternator & starter motors, so I unbolted the alternator and headed off to Advance Auto Parts fully expecting to be told it was shot.

The result was that the alternator is working perfectly...

So this leads me to the question....what can be wrong with the system?

Do these 75A fuses sometimes appear to be OK but they have blown in some area that's not visible?

Can anybody advise me of a simple logic test to narrow down where the problem is?

Cheers in advance

No ideas yet?

Time to put it all back together and await the suggestions then

Well a bit of an update today.

Re-installed the alternator and took the flat battery up to Advance Auto Parts to take advantage of their free charging service. On the way back popped in to Harbor Freight to pick up a trickle charger for $5.99.

Collected the charged battery from Advance Auto Parts a couple of hours later. (The guy on the desk checked the battery and advised that the volts were good but the CCA were a bit on the low side.)

Re-fitted the battery to the car and turned the key - noticed that none of the dash lights illuminated? The Clock section was lit up but no sign of the LCD display.

Cranked the engine and the car started immediately like any good Japanese car should after sitting for over 3 months without use

So, I put my voltmeter across the terminals of the battery and I've got over 12v but when I rev the car the volts are not increasing - they actually drop. I'm assuming this is because the alternator is still not charging the battery?

Does anybody know if the lack of dash lights and clock display... points to a fuse that's stopping the alternator charging as well?

turn your a/c on and radio etc. See if the volts are higher then. Use your volt meter and check that fuse for ohms. sometimes they look good but are actually burnt. For the dash, perhaps you have a bad grounding somewhere?
Check the ground wire that goes to your intake manifold. Mine was loose before and caused problems

Florida240sx wrote:turn your a/c on and radio etc. See if the volts are higher then. Use your volt meter and check that fuse for ohms. sometimes they look good but are actually burnt. For the dash, perhaps you have a bad grounding somewhere?
Check the ground wire that goes to your intake manifold. Mine was loose before and caused problems

I'm back in Sarasota again (was in Orlando all week) so will have a look at some point this weekend.

Will report back soonest

Now that I've got the battery charged and the car running I've not discovered another (larger problem) even although it appears that the alternator is still not charging the battery...

I have no power to almost everything in the car...

No dash lights when I turn on the ignition (but the car starts fine)
The only thing that lights up is the clock but the LCD part is not displayed
The windows do not operate
The radio does not come on
The front and rear lights are not working

The air blowers change position and the a/c kicks in as I heard a change in engine note and the selector switched illuminates but the fan does not work.

All of the fuses appear to be OK...

The only thing that looked bad when checking everything was the red connector block on the positive battery terminal which I have disassembled and removed to get good connections....

Could removing this red terminal connector cause all of these issues?

Now that I've got the battery charged and the car running I've not discovered another (larger problem) even although it appears that the alternator is still not charging the battery...

I have no power to almost everything in the car...

No dash lights when I turn on the ignition (but the car starts fine)
The only thing that lights up is the clock but the LCD part is not displayed
The windows do not operate
The radio does not come on
The front and rear lights are not working

The air blowers change position and the a/c kicks in as I heard a change in engine note and the selector switched illuminates but the fan does not work.

All of the fuses appear to be OK...

The only thing that looked bad when checking everything was the red connector block on the positive battery terminal which I have disassembled and removed to get good connections....

Could removing this red terminal connector cause all of these issues?

Well it depends if you connected BOTH the wires that used to go to the red connector to the battery. If not than yes..... That's the issue.

Well yesterday I went to the local breakers yard and picked up a length of cable from a Maxima that uses the same battery terminal arrangement as the 240SX.

I disassembled this and used the new red connector (which is in great shape) and put this onto my car.

No change in situation..

I'm trying to see the logic in this but it's certainly escaping me at the moment - there must be something I'm overloooking that gives power to all of the accessories but allows the car to start..?

When you connect the electrics to the battery there is the main cable and then two separate smaller gauge cables that connect into the red connector block can anybody advise what the function is for the following:

1. The thick large sized cable.
2. The two smaller cables going into the red connector.

I noticed that on many cars at the breakers yard the red connector has simply been cut off and the two smaller cables simply connected to the battery terminal - makes me wonder why you'd need the red conenctor in the first place?

Well today I tried hard wiring the two connectors to the battery terminal as well as the other thicker lead and no change to the situation.

I've now put it all back together using the red terminal block and the normal layout.

Car is starting fine - looks like my front light work on dip and full beam but not the rear lights. Side lights and brake lights are also not working....

Something that's just come to mind here....

Before any of this trouble started - the real problem I had was a leaking fuel tank - cracked at the support strap on the passenger side.

I did disconnect the wiring to the fuel tank as I was going to drain it from the top (which didn't happen in the end). When I first tried to start the car - I forgot to reconnect the connectors.... I noticed at that point the LCD part of the clock did not light up black and then when the car just kept turning over realised that the fuel pump wasn't connected!

Once I reconnected the wiring the car started but died and that's when I found out that the alternator wasn't charging....

Hopefully this might be starting to build up a picture for somebody that might see the error of my ways....

Have had my cracked gas tank replaced at the weekend - still this ongoing problem with the electrics though....

OK - the 100A fuse is blown - anybody got a spare they want to sell?

OK - the 100A fuse is blown - anybody got a spare they want to sell?

Well by bending the blown part of the fuse together to make a contact - I can confirm that all of the dashlights and other electrical items now work.

Just need to replace that fuse now and all will be well

Well I'm Glad you figured that out. I was going to say recheck all the fuses, but you found it. Advance and Autozone have those fuses i believe. Haven't replaced them on mine so not quite sure.

Yeah I'm glad about that - it was all looking a bit bleak with the gas tank needing swapped out then this electrical problem!

Thankfully, it's just a case of replacing the fuse and topping up the coolant (pipe had to be disconnected when removing/re-installing the alternator.

I see you are from Lakeland - this car was bought from a guy (ex-navy) in Lakeland (back in 2001) and I used to live at Parke33 for a couple of years too.

Thanks for the heads up on Advance and Autozone - I'll look them up this afternoon.

Hey Im new to this forum, I have the same problem with my 240 where I put the new alternator in and used a buddys good battery and it ran but the electrics didnt work... the windows taillights dash (except clock) radio etc etc. I know that you said it was the 100A fuse but I dont know where that is i know that there is a box under the hood and that there is a hidden one somewhere any help you can provide will be appreciated thanks so much!

kviper52 wrote:Hey Im new to this forum, I have the same problem with my 240 where I put the new alternator in and used a buddys good battery and it ran but the electrics didnt work... the windows taillights dash (except clock) radio etc etc. I know that you said it was the 100A fuse but I dont know where that is i know that there is a box under the hood and that there is a hidden one somewhere any help you can provide will be appreciated thanks so much!

Here you go:

wtb-100-amp-fuse-s14-1995-240sx-se-t557853.html

I read all of the posts from everyone because I had the same issues. Wouldn't you know it, replacing the 100A fuse did the trick. I also found this website to help replace the fuse.

http://www.g20.net/forum/showthread.php ... y-fuse-P11

gtd65 wrote:

kviper52 wrote:Hey Im new to this forum, I have the same problem with my 240 where I put the new alternator in and used a buddys good battery and it ran but the electrics didnt work... the windows taillights dash (except clock) radio etc etc. I know that you said it was the 100A fuse but I dont know where that is i know that there is a box under the hood and that there is a hidden one somewhere any help you can provide will be appreciated thanks so much!

Here you go:

[url]<a href="wtb-100-amp-fuse-s14-1995-240sx-se-t557853.html[/url" rel="nofollow" target="_blank" title="Link added by VigLink" class="vglnk"><span>http</span><span>://</span><span>forums</span><span>.</span><span>nicoclub</span><span>.</span><span>com</span><span>/</span><span>wtb</span><span>-</span><span>100</span><span>-</span><span>amp</span><span>-</span><span>fuse</span><span>-</span><span>s14</span><span>-</span><span>1995</span><span>-</span><span>240sx</span><span>-</span><span>se</span><span>-</span><span>t557853</span><span>.</span><span>html</span><span>[/</span><span>url</span></a>]

i have the same problem and i have not been able to figure out what the problem is.
i went to nissan and picked up the nissan 240sx service manual, i looked at the charging system diagram and shows all the wiring of the alternator and relays, fuses etc...

i followed the diagram and had no luck, all fuses and relays are good, all plugs and wires from that charging system seem to have the 12v and the ground as well.

another thing i noticed is my battery light on the dash is not working at all; i did some research and people were saying that the alternator wont wont get signal to charge unless that light works, so i came across the bulb check relay- and well it seems to be working as well and i also tested the wires and also got the 11.8v (obviously not 12.6v since battery isnt fully charged anymore)

but nothing bulb is still out. alternator is new as well, battery is good. so what could the problem be??

JsoulD8m did you ever find out what the problem was? I have the same problem.