Bypassing Cavalier "fuseable" link, to alt post or batt post

[CanuckQx4]

My girlfriends 99 cavalier 2.2L is having charging problems. With the car running it stays at 12 volts.

Tried a junkyard alt, still 12 volts while running.

I did some research online and read a few guys mention that there is a fusible link wire that goes to the starter

Could this wire being bad cause the alt not to charge?

Anyways I took a look at the fusible links which both appear to connect to the starter post. I want to simply add my own fused wire instead of fixing these ones to get the job done tonight

So I connect the fused wire straight to the starter post and run it to the _____?? Alt post? Batt ++

Apprecaite any help!!!

[frapjap]

I have some suggestions for you since its a GM and I had a very similar problem with my Trans Am.
Re-tighten all Ground leads, including searching for a ribbon cable on the back firewall leading to the back of the engine ( just loose/tight the one on the body ! ), There is a small one leading away from the battery cable to battery connection and to the body, and of course the main connection from battery to Engine Block. There's also a couple small ones for the headlight harness along the front edge of the engine bay too - might as well check them too while the 10mm socket is loaded !

So, all of your grounds are okay, next you'll want to confirm that the link is the problem, take your jumper cables and run one color from the positive on the battery to the alternator post. You should start seeing charge on the gauge. Assuming it has a gauge. This will confirm a bad link somewhere.

Next, be sure to check BOTH sides of the wire around every fusible link !!!*** I've had to cut/splice MANY fusible links onto harnesses over the years when using them for swaps...Bad fusible links are almost as common as getting a parts car with the radio plugs cut out of it !

You'll know when you find one. I pulled the positive leads off of the battery's distributing terminal and had the alternator cable fusible link fall apart in my hands!

As for a replacement, its sold for next to nothing in spools.
Autozone has it, as does Napa.
They are in the fuse/bulb section on the sales floor.
Just get a link the same gauge as the one you are replacing.

***Just to be sure I'm helping you enough- from your post, its not 100% clear if you know what you're looking for (I wasn't the first time!) You're looking for what is basically a wire that has a metal that corrodes/burns up when to much. It looks just like any other wire but gets a weird, gummy, stretchy texture to it when it fails when to much power surges through it causing a short. It won't be visible when it fails because the wire breaks in the insulation, so feel around and when you find it, cut it out from the actual harness and splice in a new length.
On GM cars it is found at the battery terminal ends of the power cables and by the starter.

[CanuckQx4]

DO you think this fusible link would cause the alt not to turn on and start charging though??

We dont have a local napa or part source and I was hoping to do this tonight so I dont need to drive my girlfriend home and to work/school so I was hoping to add my own fused wire for now

Im unsure if I jump from the starter post to the alt post, or from the starter post to the battery +

I just dont get why either alt isnt producing 14+ volts while running!!!

[frapjap]

DO you think this fusible link would cause the alt not to turn on and start charging though??

We dont have a local napa or part source and I was hoping to do this tonight so I dont need to drive my girlfriend home and to work/school so I was hoping to add my own fused wire for now

Im unsure if I jump from the starter post to the alt post, or from the starter post to the battery +

I just dont get why either alt isnt producing 14+ volts while running!!!

Absolutely! That was the problem I had when I accidentally shorted mine by bumping a valve cover into the alternator (shame on me for not disconnecting the battery!).

Confirm it with the jumper cable test- positive battery terminal to the alternator post. Leave the starter out of the equation. This will complete the interrupted circuit and start charging if that is the issue. If it is, you can just run a crude, new power wire from the alternator post to the positive battery terminal (assuming you have long enough, thick enough gauge wire) for the time being.

Though, honestly, it'll take you about 5 minutes to replace the link tomorrow.

[CanuckQx4]

ok sweet I will try a 4 gauge power wire from the alt + post straight to the battery +

How come the alternator post still doesnt show up as 14 volts when the car is running?

Shouldnt there be 14V at the alt post in order for this fix to work??

[frapjap]

Its not getting power right now.

[CanuckQx4]

Doesnt alt feed battery?

[frapjap]

Alternator charges the battery so it doesn't get depleted, battery distributes power to everything else. Thats why your power locks, windows, and radio work when the car is off.
Right now, the battery is carrying your whole electrical system. You can even drive on it, but don't expect to get more an 20 miles, less with your lights and/or defrosters on.

[CanuckQx4]

Ok Ill go try first with the jumper cable to verify it works then if it does Ill make a nice fused 4 gauge wire

Hope it works!!!! thanks so far man, I was stumped on this one

[CanuckQx4]

Jumping the alt post to the battery pos didnt work, stayed at 12 volts while running

I did this with the junkyard alt though that I cant guarantee is even working

Should I put the oem alt back in and try again??

I swapped the alts because the car died on my girlfriend, wasnt charging, I assumed alternator since the batt is good and strong and will run the car for her trips to work since I have put it on the charger her last 2 trips. Maybe this fuseable link is what was faulty originally??

Or should I be looking elsewhere

[PapaSmurf2k3]

I don't know enough about that car to really be of any use, but is the voltage regulator internal to the alternator, or do they use an external one, like some chrysler units?

[CanuckQx4]

i dont really know, i went back to the junkyard and the onl cav they had left had a rusted and seized alternator

She really doesnt wanna buy a new alt for this beater

[PapaSmurf2k3]

yeah I just looked them up... holy hell they are expensive. Strange for GM.

I would think if you bypassed the fusible link, then that isn't the problem and you should start looking elsewhere. I would think you're right, and the alternator should output 14v or so at the harness connector (without anything drawing it down that is), so if you disconnect everything and spin the alternator over 2000 RPM or so, you SHOULD see ~14v...
I'm no electrical engineer though.

[sx moneypit]

The charging system on your car uses the PCM to turn the voltage regulator on.
Kent-Moore makes a tester that bypasses the PCM to determine whether or not it is a faulty alternator.I would suggest that you take the car to a competent shop to get it checked out. It will save you a lot of time and frustration.

[CanuckQx4]

anyway I can bypass it myself??

[sx moneypit]

anyway I can bypass it myself??

When i go to lunch i will dig around and see what i can find out.

[sx moneypit]

Check the small red wire at the alternator connector with a digital voltmeter with the car running ,if you are getting a 5 volt signal then the alternator is bad.