# 1994 sentra electrical problems



## pcbisnice (Aug 19, 2008)

I apologize in advance for the length of this post, i felt it was necessary to explain the problem correctly. Last night i bought a 1994 sentra xe and drove it home 20+ miles without a problem. The car has fog lights installed to a switch thats inside the car. I forgot to turn those fog lights off when i got out of the car last night and i woke up today to find the battery completely dead. No biggie i thought, so i had a friend come over to jump start me. Car starts right up. We talk for a few minutes and i unhook the negative cable of the jumper cables from my car and it immediately shuts off. Now im thinking theres a problem with the charging system. So i hook the jumper cables back up and start the car up and let it run for 10 minutes or so. unhook the cables and the car is idling fine. Thinking it was a one time problem i proceeded to put my tools away and left the car running so it could continue to charge up. i come back outside and the car has shut off again. Sound like alternator to you guys? I notice a tiny bit of smoke coming from an electrical connector that comes from a white cable that leads off of the positive terminal of the battery. the wire was steaming hot from the battery to the connector less then 6 inches down the wire, but on the other side of the connector further down the wire, the temperature of the wire is normal. I'm not sure, but this wire appears to lead to a fuse box near the battery. There was a 20 amp fuse labled ABE SOL that this wire APPEARS to run to, i have no idea what that is or if i was even following the right wire from the battery. but the fuse was bad and i replaced it, which made no difference. If i unplug that connector that is heating up the car still runs, and the plug no longer heats up (of course). Does this connector coming off of the battery have anything to do with the charging system? I guess my question is, what is that connector that comes off of the positive post on a white wire off the battery? I need to figure out why its getting hot to fast, and what it does to find out if its interfering with my charging system. any suggestions to something i can check or mess with to fix this problem? i did a few searches on the forums, but couldn't find what i was looking for. I need to get this car running good in 3 days because i have to move. bad timing!

Oh and not sure if it matters, but my battery light is not on, and has never been since i got it last night. when when its trying to die after jumping it the battery light does not come on.


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## gimlet (Nov 21, 2007)

PCB,

I think the 20A fuse you are seeing is labeled ABS SOL, which is for the ABS system, if your car has one. My LE has no ABS, but has a fuse anyway.

Looking in my '94 factory manual (page EL-8), it looks like the positive battery terminal connects to:

1. Several fuses in the E23 block:
1a. 25A fuse to the ECCS/ECM
1b. 30A fuse to the ignition switch
1c. 30A to the SMJ (super multiple junction - main harness/engine room harness)
2a. The charging system
2b. Cooling fan relay (SR20 only?)

Hope this helps...smoking wires next to the battery don't sound good at all - be careful! Might be a silly question, but have you checked the battery's charge?

Tom


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## pcbisnice (Aug 19, 2008)

Thanks for your response. I have not checked the charge of the battery. even if the batterys low charge/dead the car would still run when jump started as long as the alternator is doing its job right? You said one of the wires coming off of the positive terminal of the battery is indeed part of the charging system. Does that happen to be the white wire that has a plug of some sort about 4-6 inches after the positive terminal? Cause thats the one i unplugged because it was heating up

Also, isn' there some sort of battery light in these cars? i have yet to see one come on at anytime.


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## pcbisnice (Aug 19, 2008)

Update: 

I took the battery inside and charged it up and had a friend come over with a voltmeter and we tried reading the battery and alternator. With the car off the battery read 0 volts. with the car on the battery read 12 volts exactly. Couldn't figure out how to test the alternator, but after a couple minutes we checked the battery again and it was at 11.6 volts and slowly dropping. We stopped the test around 10.9 volts. This would mean the alternator is not keeping the battery charged correct? can an alternator belt too tight make this happen? i have no idea how tight/loose it should be.

Also, the wire that i have been calling white that runs off the battery is actually black for the first 6 inches or so, then at some sort of connector it changes to white. 

I just ran the car for a solid 20 minutes and it didn't die. But nothing electrical works except the horn and headlights. the ac, clock, radio, cruise button, nothing else works. im guessing its trying to save power? do these cars have an option like that?


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## 79kz400 (Aug 19, 2004)

Sounds like you deep cycled the battery for the last time and it is toast.

I recommend that you go to the local auto parts store and ask them to check your charging system. They do this free hoping you'll buy something.

You alt belt should have about 1/2 inch of deflection. Make sure you notice the bolt on the side of the bracket that locks the adjustment bolt in place of you decide to mess with it.

These cars don't save power. Did you check your fusible links? Check them visually and with your fingers. They should look good and feel solid. Burnt ones look burnt and are flimsy.


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## pcbisnice (Aug 19, 2008)

sorry i dont' know what a fusible link is, or what it looks like. Is it a fuse in the fuse box under the hood on the right side of the battery near the drivers side wheel?

Upon further inspection it appears there is no fusible link. I don't know what it looks like, but i can't find anything with a fuse thats NOT inside a fuse box.


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## kizer24 (Mar 23, 2008)

Fusible links can come in many different designs. Here is a link to a little more info.

Electrical System: Fusible Link


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## pcbisnice (Aug 19, 2008)

i guess whoever had the car before me removed the fusible link off the battery. because i can not find anything that looks like one. That could explain my battery not being charged. not sure where to start on my temp gauge, wipers, signals, rear lights, and dome light not working.


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## gimlet (Nov 21, 2007)

The smoke sure does sound like a fusible link. I accidentally charged a battery backwards once, luckily the fusible link did its job and saved me from a very expensive and very stupid problem.

Something sure does sound wrong. I think the other posters are right in suggesting having the charging system diagnosed, as well as it being time for a new battery. Good luck!


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## pcbisnice (Aug 19, 2008)

There's 3 wires coming off of the positive post of the battery. The 2 smaller ones both eventually lead into a harness on the right side of the battery. The smallest one is black and leads to some sort of plastic electrical connector. On the other end of this electrical connector the wire is white all the way to the harness. The connector and the wire on the battery side of it are what started smoking, and got extremely hot after starting the car. the medium sized wire is red and runs to a coupler that is connected to more wire, and to another coupler, then the rest of the way to the harness. I think the fusible link would of been between those 2 couplers and someone removed it? Also, anyone know what that plastic connector coming off of the small black wire is? it definitely does not look like a fuse.


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## gimlet (Nov 21, 2007)

Looks like someone patched in some new cables. Not that I'm much good for comparison, as someone did a complete hackjob on mine putting in an alarm system, which I am currently ripping out.


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## pcbisnice (Aug 19, 2008)

So i went to autozone this morning and they tested the charging system. Results were No output at alternator, check wires. Sure enough check a wire and when i wiggle it the car shuts off. so thinking thats the problem i rewired it as good as i could and drove the car back down to autozone to get retested. Well, same results, "no output at alternator. check wiring" 

Can someone please tell me how many wires i should have coming off of the positive battery terminal, as well as the negative terminal? im wonding if i got them mixed up. I need to find which wire goes to the alternator. Theres a wire thats not hooked up to the battery because if i touch it to the positive side it sparks like crazy and melts the post. Im guessing this wire is the one that feeds the alternator. which would explain why theres no output at the alternator. Could someone post a picture or a link of the battery, the cables coming off of it, and perhaps a pic of the alternator setup? i want to compare mine with someone elses. Because however had this car before me sure did hack everything up. I also have yet to see any battery light, or warning light of any kind come on.

Can someone look at the pictures i posted above and tell me if they see a fusible link, or if it looks like someone removed it?


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## gimlet (Nov 21, 2007)

pcbisnice said:


> Update:
> I just ran the car for a solid 20 minutes and it didn't die. But nothing electrical works except the horn and headlights. the ac, clock, radio, cruise button, nothing else works. im guessing its trying to save power? do these cars have an option like that?


No, the electronics system does not know how to save power (other than storing energy in the battery). My guess is blown fuses and/or fusible links. That's where I would look first...and that battery cable that gets hot. They're not supposed to do that!


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## TheBrownRobert (Aug 28, 2007)

If the wire pops, hisses, and smokes when attached to the battery, you have a short somewhere; this short may have killed your alternator. I believe the fog lamps are responsible for your problem. The last owner butchered your battery wires, which is a good reason to believe that the other wires connecting the fog lamps are just as bad. I would also recommend paying special attention to the fog lamp switch because it may be shorting out due to improper wiring.


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## luke12345 (Jan 10, 2009)

Hey, I know this thread is a little old now, but did you ever figure out the cause of your problems? May have something simliar going on...


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