Jay07

I have a 98 ls1 Z28, lately the volt gauges show that after I have the car turned on for a few minutes it starts dropping past 13V and stays in between the 13v and 8v. After the car heats ups and I'm at idle it will turn off and the volts drop past 8v. It feels as if it's the fuel not getting to the car I just turn the key back and forth a few times and it turns on. Friday it threw a code for the MAnifold Absolute Pressure / BARO high input... I'm getting extremely frustrated and can't figure out what it could be. I already replaced the alternator and it is still doing it. Can anyone give me some ideas ?

Jay07

Any ideas ??

Texas-Firehawk

iTrader: (1)

is your security light on?

Jay07

Actually it is on.. How could that effect the vehicles performance ?

00pooterSS

iTrader: (40)

It could also be the connector that plugs into the alternator. You can get a new one at Napa, they are cheap and easy to install.

What you are describing is the battery dying while driving. So it definately sounds like you have a charging issue. I went through about 10 alternators before I finally gave up and got one from the junk yard, if you want to do some reading, look up my thread if you would like to do some reading about it.

https://ls1tech.com/forums/generatio...-failures.html

Jay07

Ok cool I might have to do that and go to a higher amp alternator. As soon as my car is on the it's drops way past the 13to almost 8 and if I turn the AC on the car idles at 500rpm, oil pressure drops. The car pretty much tries to turn off.

00pooterSS

iTrader: (40)

Try not to get overwhelmed, fix one problem at a time, it's obvious you have a charging problem so I would start there. Your oil pressure dies and the car is acting funny because the battery is dying and so is the engine. Make sure you have oil pressure when it is idling, don't want to hurt the motor.

Try this as a quick test, start the car and then pull/push on the connector (the small one wire plug that goes into the top of the alternator) see if when you do this if the voltage starts to jump around or if it starts to come up. If so replace that connector. Actually I would replace the connector no matter what. I did on mine because I saw how bad it is designed and that it could easily fail. Another member on here had problems similar to you and his connector was bad.

What you need is an "exciter wire pigtail" this is the wire that turns the alternator on when the pulley is turning. If it does not have a good connection or if the signal is not present the alternator will not charge.

Jay07

Ok thanks I will try and test that out.. But the oil pressure is at 40 while it's at idle and at 13v. I'll go tomorrow to napa and replace the wire.. I appreciate all y'alls help and I'll keep y'all posted on how it works after the wire is replaced... But would that cause my security light to stay on ?

00pooterSS

iTrader: (40)

Oil pressure sounds good then. The security light is on while it's running? I don't really know what would have triggered yours but mine came on one time and the car would not run. That was triggered by my ignition key, for some reason it didn't read the key right and triggered the VATS system and wouldn't allow the car to run.

Jay07

oh ok, yea mine runs fine until the volts start to drop. but i have a quick question for yall... the 03 escalde 145 amp i bought is a 4-PIN, but the plug on my camaro that plugs into the amp only has 1-pin to plug into if yall get what im saying. is this ok or do i have to modify anything ?

00pooterSS

iTrader: (40)

Your alternator connector on your car should have 4 PINS but only 1 WIRE. Hope that clears up the confusion. And no you do not need to modify anything just plug it in.

BUT those connectors do go bad so I HIGHLY HIGHLY recommend you replace it, they are very cheap and very easy to replace. As I posted above that is the exciter wire and you can buy an exciter wire pigtail from NAPA, it will most likely come with 4 wires coming out of it. Cut off your old connector and look at which pin on the connector has the wire run to it. Clip off the 3 wires that won't be used on the new connector, and wire up the remaining wire on the new connector to the single wire on your car that comes out of the wiring harness that you previously cut.

Jay07

Ok I went to napa and told them I needed the exciter wire pigtail and they looked at ms like a retard and said they didn't carry that lol ?

00pooterSS

iTrader: (40)

Well crap, I don't know thats where I got mine. I'll see if I can look it up.

Here it is at Summit but I don't remember paying all that much for it.

http://www.summitracing.com/parts/SMP-S754/?rtype=10


Okay found it at Oreilly, it's a AC Delco part PN# PT1136

I got mine from NAPA so you can try going back there or go to orielly

http://www.oreillyauto.com/site/c/se...aro&vi=1361450

Jay07

Ok cool thanks alot I'll go to Oreilys tomorrow

00pooterSS

iTrader: (40)

Did the connector help?

Jay07

Helped a little. It doesnt go down so low. But it's still doing it nonetheless. I guess I still need an alternator

00pooterSS

iTrader: (40)

Well I had many new ones fail also. They would charge until the motor was warm and then they would stop charging. If the car was cold they worked. Some of them completely failed. Some only worked if I revved up the engine. That's why I went to the junk yard, the junkyard alternator was better than the new ones off the shelf.

Jay07

Yea mine works fine until the car heats up then it shuts off at idle.. Also what could I do about my security light being on all the time. As sol
As I turn the car on the light comes on and doesn't turn off

00pooterSS

iTrader: (40)

Your alternator is bad, as far as the securtiy light I really don't know man.

Jay07

Damn I was hoping it wouldn't be bad. I bought it about 2-4 months ago and don't have the receipt. I guess I'ma have to get a 145 or bigger alternator for i, does anyone know over a good website or someone that rebuild/has one for sale ?