Yay! More trouble with my neon!

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 6:42 pm

So Tuesday I was headed to go pay my car payment, and on the interstate, the little battery light came on. I had the lights and the radio on, and despite turning them off, it stayed on. I was able to drive successfully another 10 miles, and the car never stalled.

After working all night, I start the car the next morning and the light wasn't on. I get about half a mile down the road, and the light comes on. I stop to get gas and when i start the car, it comes on again after about half a mile or so. I drive approximately 5 miles and the lights are now dim and I can barely make out the interior lights. So, I pull over into a parking lot.

I think, with that wonderful Haynes manual at my side (cough), that it is the alternator. So, on Thursday, after a long evening of changing the alternator (and the bruised knuckles to prove it) I start the car, and it runs fine for a bit and then it gives me the battery light again.

The next day, which was today, I change the battery out, because the old one apparently had a problem with the discharge rate. Well, I start the car today, it runs fine for a little, and I STILL get the battery light.

Before you ask, I've used the electronic tester. It gives me 12V when the car is off, 12V when the car is on, and 11.5 when all the accessories are on (AC, radio, rear defrost, and headlights). The alternator is new, the battery is new, and it still not charging. I have also replaced all of the fuses, just in case.

This leads me to believe it has to be the wires. Would that be correct to assume? Also, how would I go about testing the wires to find out? Next, where do I go about finding new terminals for my battery? The only ones Advance Auto and AutoZone have look like this:

where I need |:O for the positive terminal (because there is a red wire that goes on both sides of the terminal.

The codes it is giving me are 1682 and 1684. 1684 doesn't worry me because I know i've disconnected the battery in the last 50 starts. The other nearly as obvious one says that the charging system voltage is low, and I know that from the battery light and headlights dimming ^_^.

Any help is appreciated, and thanks!

BlackRoseRacing · Post by **BlackRoseRacing** » Fri Jan 04, 2008 7:04 pm

The so called NEW alternator, where did you get it from?
From past experiences, new or rebuilt, I have alternators,starters,batteries,etc tested before I leave the store. AutoZone, AdvanceAuto, NAPA, they all have test equipment to test things like this in the store. Believe it or not, even something NEW can be bad.....

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 7:31 pm

I purchased it from Advance Auto. There is always the chance that it is the alternator, but I just sunk $130 and about 7 hours into installing it (it wouldn't have taken so long but it was in a parking lot, and my girlfriend's truck has a wonderful heater on the coldest day of the year so far), I hate to think I'm gonna have to remove it again

BlackRoseRacing · Post by **BlackRoseRacing** » Fri Jan 04, 2008 8:00 pm

Me personally I dont deal with Advance too often anymore due to purchasing bad parts right off the shelf....
For example:
An electric inline fuel pump, brand new never opened, I installed it onto a project and when I turned the project on, the pump never worked, I double checked the wiring and the pump was not working at all, Advance started to give me a hassle at the counter stating I wired it up wrong, I told them to test it themselves and it was in fact bad...brand new, but defective...
I'm not stating this is your problem, but I honestly would get the laternator tested before assuming any of the wiring is bad..

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 8:05 pm

I know you aren't saying that's what it is, it's that it didn't cross my mind and really don't want to think about it

Yeah, thank you for helping, before you think I'm trying to be an arse or something

I already needed to change the battery wires, I think, so that is what I am hoping it is. Otherwise, I do still have the receipt for the alternator.

edit: fixed some grammar

Neon316 · Post by **Neon316** » Fri Jan 04, 2008 8:11 pm

my battery reads 14.5 when running with lights on

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 8:13 pm

Yeah, mine is supposed to be like 13.5 V when it is running without accessories, which is what it was before when I tested it a couple of months ago.

This sucks.

Post by **occasional demons** » Fri Jan 04, 2008 8:27 pm

If the alternator is not bad, it could be either the wires to the PCM or the PCM itself as it controls the alternator output. I'm not sure if the alt is like the old school units with external regulators, but on those you could jump the two field wires to test the alt. If it was good then it would put out the max voltage it could produce. IF these can be tested that way and your PCM is bad, I would get a mid 70's voltage regulator (solid state) and wire it in. screw getting a PCM over an alternator driver issue. I will have to check the wiring diagram to see if it is even an option. I've wondered about this, since my Cherokee is the same, but never researched it. Yet.

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 8:31 pm

Sadly, the voltage regulator is internal on these alternators, so there's not a way to to test that specifically. I have yet to test any of the wires while it is running, so I don't know yet.

BlackRoseRacing · Post by **BlackRoseRacing** » Fri Jan 04, 2008 8:34 pm

The pcm does control the alternator, but, you should not have less than 12volts at idle even with ALL accessories running, my car produces about 13-14volts at idle, and thats with all accessories running!

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 8:43 pm

Yeah, BRR, keep rubbing it in that you have a running Neon

Just kidding.

Like I said, in the original post, I tested it with the tester, and it was 12 volts. I can't remember the last time voltage that low was a good thing

.

Anyone know where to get a set of wires, that would be specific to my car? Or am I going to have to rig this whole thing up?

jT · Post by jT » Fri Jan 04, 2008 9:42 pm

i saw in a post somewhere that a new set of OEM battery cables were well over $100.. i dont remember if it was BRR that did a price quote or someone else..

it is obviously cheaper to do it up yourself, although a little more of a hassle.. if i ever get around to popping in a new battery im going to redo my wires too at the same time

doing it yourself will also allow you to upgrade to 4awg wiring if you so chose to do so

there are threads already on redoing the battery cables and what you need for parts so i wont repost anything here

Post by **occasional demons** » Fri Jan 04, 2008 9:43 pm

OK my theroy should work with the old school regulator, but I would check the fusible link at the starter first as it may be corroded or partially melted. I learned that our pre-ngc cars do have a battery temp sensor it's the IAT sensor used for both functions. But atleast you got some idea now which wires to check for continuity and where to find them. If you have power at pin 2 then ground pin 1 and the alternator should put out max output. But check the circuit between the output and the battery first, if you got a bad connection/link then it won't matter if it's putting out 30 volts it's not going to reach the battery. Basically the generator field driver circuit A pulses the path to ground to reach the target voltage, so it is also possible there is a grounding issue. The fact that it runs for a while before you get the cel makes it harder to find. At the worst you'll end up taking it out to confirm if it's good or bad, 'cause I doubt they will be able to check it in the car. as you know it isn't exactly acessable!

Wizzard~Of~Ozz · Post by **Wizzard~Of~Ozz** » Fri Jan 04, 2008 10:15 pm

If you want to test the alternator now, fire it up, and meter the voltage from the Alt, to ground. If it isn't 13.8v (standard 12v automotive) then the alt isn't outputting the correct voltage. This bypasses all the wiring. If you can, disconnect the 12v lead from the alt. this will remove any possible power drains in the vehicle. You have it hooked up to a 130hp alt tester at that point.

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 10:31 pm

I appreciate the help! My question for you, Wizzard, is from where on the alternator do I test? From the connection to the cable that goes towards the battery? Or somewhere else? Just want to be able to do this right.

Thanks!

Wizzard~Of~Ozz · Post by **Wizzard~Of~Ozz** » Fri Jan 04, 2008 10:43 pm

I'm more familiar with doing it with more traditional Alts that had a single red wire going to them, Looking at the diagrams above from the FSM, you have 3 wires coming from the alt, Dk Green, Dk Green/Orange and Black/Grey. The black/grey is the one that looks to be carrying the voltage back. If there is a bad wire, the reading at that point should still be 13.8v, if it is a bad alt or there is a short the voltage here will show the same voltage as @ the battery. Not sure if you can get into the connector, but a strand of fine wire (cat5 cable) stripped and wrapped around the lead should allow you to slip it in the back.

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 11:03 pm

To get to this wire, I actually have to be underneath the vehicle. There are technically two wires going to the alternator, but one of them contains the dark green and the dark green/orange, and that one obviously (by not only the schematic but also from installing it and seeing the connection) goes to the pcm/shutoff relay - it connects with one of those big plastic connectors. The other one is held on with a screw, and the handy dandy useless Haynes book says it goes to the battery, though schematics above and in the Haynes book say it goes to the starter and THEN the battery.

Wizzard~Of~Ozz · Post by **Wizzard~Of~Ozz** » Fri Jan 04, 2008 11:16 pm

Ahh good, Then they aren't that different after all. The Haynes book...... Is it me, or is this one a little on the lean side compared to previous books (and what the hell is the little rad thing I have below my firewall).

The separate wire would be the one you are looking for (should be black/grey right? perfect colour for a +12v line) and yes, it goes to the starter as a common connection point, then to the batt. (no good reason other then, there is only one running at any given time so why not). This also gives you the advantage of knowing your wire going to the starter is good (you can start it right?) leaving the only wire that could be bad as a blk/gy wire between the starter and alt. (which according to our dear old Haynes has a fusable link that could go bad..) This of course pending a quick test that the alt is in fact working in the first place.

FinalSomnia · Post by **FinalSomnia** » Fri Jan 04, 2008 11:30 pm

Okay, so when I go looking for this fusible link to see if it is blown.... Anyone know where it would be? Is it in-line or something? I've got about 7 hours before I leave work, so I'm asking the questions now, so that I'll be better prepared for the next journey into my engine block.

Wizzard~Of~Ozz · Post by **Wizzard~Of~Ozz** » Fri Jan 04, 2008 11:58 pm

There is a brief mention on page 12-4,3 in the Haynes manual..

Oh, and I forgot, chances are the Alt wire does run straight back to the main fuse box, Electrical drawings aren't always the correct points that the physical wires connect.

FinalSomnia · Post by **FinalSomnia** » Sat Jan 05, 2008 1:19 am

Well, I did replace all the fuses both in the Power Distribution Center and in the interior fusebox... not sure if there's another one than that or not, but then, those are the two I know about. I'm not an expert (and were I, I'd be giving help rather than asking for it

) so again, thanks to everyone that is/has/may possibly helping/helped/help!

Post by **occasional demons** » Sat Jan 05, 2008 2:18 am

The fusible link is at the starter. the wire that is held on with the nut/screw is the one that you need to check for power.

FinalSomnia · Post by **FinalSomnia** » Sun Jan 06, 2008 3:32 am

So, being a newbie to car electrical stuff, do I use the positive lead on the tester on the screw on the alternator, and then use the negative lead on the body for ground to test it, or what? Sorry for all the questions, I just need to know how to do it right

BlackRoseRacing · Post by **BlackRoseRacing** » Sun Jan 06, 2008 8:13 am

Negative test lead = Chassis ground, alt body, engine block...
positive test lead = actual probe

Post by **occasional demons** » Sun Jan 06, 2008 12:12 pm

^^^^^^ Werd! There should also be battery voltage at the A11 8 gauge BK/GY connector with the engine off. This would be a way to check your fusible link. tho not fool proof. The time to check for voltages would be when you have the battery light. or a before and after.