The engine starts up but dies with in seconds.

It sounds like it's not making a circuit But I haven't done anything since last driving it except pulling the battery to recharge it because it died.

Any suggestions? Has no current codes.

 

you pulled the battery to charge it? Why was it dead? Batteries don't normally go DEAD for no reason.
Did you check voltage after you charged it?

A good battery at full charge will measure from 12.6 to 12.9 volts or more. This measurment should be made with a digital multimeter directly across the battery posts with the neg battery cable disconnected. The electronics in the C5 is especially sensitive to battery voltage. While the car will start with as 12.2 volts (measured as above) the electronics and in particular the column lock electronics, are NOT happy if the voltage is 12.5 or less. Don't bother with dash gauge readigs. Those report the state of health of the charging system and NOT the state of health of the battery. With the engine running they report the approximate alternator output voltage. Approximate because the gauges are after the ignition switch which is known to affect the readings. With engine off and key ON the reading is about worthless since many electrical circuits in the C5 are loading the battery.

I'd guess you have a bad battery...

 

I think if it's the battery or not the battery is probably going to need to be replaced eventually. Do you think it could be the alternator?

The car started for a few seconds probably 3 to 4 seconds then died. I just thought after the car starts the alternator runs the car. Do you think because the battery was low on volts that the alternator couldn't keep up off the start?

 

A dead battery will not cause a car to not continue to run after it's been started. At least, not unless the battery is completely flat and the alternator doesn't work. If you started the car off the battery, it had enough charge to fire the coils.

Something else is amiss, but I'm not the Corvette mechanic I'd like to be so I'll let someone else chime in from here

 

That's what I thought too with the battery. But I haven't messed With the grounds or anything electrical outside of the battery. I guess I'll find out tomorrow when I take the battery to be tested

 

Low voltage is an issue with any C5... even more so with a 99
I'm not an electrical engineer, hell, I barely know how a switch works. That being said, I'm not sure how the battery,starter solenoid and alternator relationship works on these cars but I do know they are prone to be trouble.

The reason I said battery is I think there may be something between the alternator and the PCM that with low voltage it says... NOPE not charging or even letting the car run...

If your battery is ok, your connections are all good.
I might suspect alternator also, but before you go buy a replacement make sure you read the link below...


The 99 can be finicky about communicating with pcm. Best option is to have the old one rebuilt if possible. Check this post. https://www.corvetteforum.com/forums...tem-fault.html

 

A C5 will crank with low voltage and may even start but then you will have problems. The electronics will not work correctly with low voltage.

Until you determine what the voltage is AT the battery we cannot start diagnostics.

Your issue is NOT the alternator.

Also, did you actually go into the dash DIC and pull the codes or were you expecting a message to be flashed on the screen?


A fully charged battery should be 12.6v or more.

It's not 12 volts it's 12.6 because each cell is 2.1 volts.

If the battery is

12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained

 

[QUOTE=dadaroo;1589681235]A C5 will crank with low voltage and may even start but then you will have problems. The electronics will not work correctly with low voltage.

Until you determine what the voltage is AT the battery we cannot start diagnostics.

Your issue is NOT the alternator.

Also, did you actually go into the dash DIC and pull the codes or were you expecting a message to be flashed on the screen?


Good question... still learning from the best

 

Really, Steve???? I am sure your Mama showed you how a switch worked when you were a little kid.

 

MAMA wore my *** out with a switch... I think it was elm?

 

Mine was HICKORY and it left nice welts!!!!!!!!!!!!

If a car CRANKS, and then RUNS and dies after you release the ignition switch from the CRANK position to the RUN position, Its more than likely a problem with the ignition switch. The ignition switch has FOUR positions.

ACC, OFF, RUN and CRANK. The circuit that allows the car to CRANK and RUN is the : HOT in RUN & START Most modules have TWO 12 VDC power supplies. A 12 Volt (HOT AT ALL TIMES) circuit & the (HOT IN RUN & START ) circuit.

Some where in this post (see below) is a list of all the Hot in Run & Start powered fuses. You should get a Volt Meter and with the ignition ON,,, Check the test slots on top of each fuse for the PCM and BCM that is powered by the (hot in run & start) circuit.


-C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html

NOTE. If this voltage is not there (for what ever reason), you will not see any DTCs because the PCM, BCM thinks that they were shut off by the ignition switch.

If it were MY car,, That's the very FIRST thing I would do.

Another thing to check is the FUEL PUMP and make sure that you have fuel pressure AFTER the initial PRIME sequence that the PCM allows the pump to make when you first turn the ignition ON.

If the pressure drops to ZERO after it runs for a second or two, the pump is NOT running after the initial prime sequence.