its a 98 c5 covertible 6spd

when i go to start it it turns for a split second and stops
if you continue to hold the key in the start position every 2 seconds it will try to start again, but wont start.

the battery is known to be good...i tested it at autozone

its not a situation where it doenst have enough grunt to turn the motor because when it does turn it really sounds like its trying to turn it strong for that split second. I think its some sort of electrical problem other than a dead battery. the volt meter shows around 12 volts when the car is off and the key is set to on
sometimes as low as 11.5

when i succsessfully get it to start it usually goes to around 13.9 and stays there occasionally making it to 14.2 but nerver higher

this just started yesterday.
it broke down at wendys and i took the battery out and went to autozone to buy another one
i figured wierd things happen when batteries die and this one is 13 months old btw
they tested it and said it was good so i took it back and put it back in
i tried to start it and it just barely fired up and then sputtered out
then after a few tries i got it to start

i havent had the column lock recall done and dont have a bbypass
i added hud last year and have long tubes
thats about all i can think of

i searched on here and it seems that others have had a problem similar but not identical
any one have any suggestions?

 

I had a similar problem. It was caused by faulty ignition switch that would kick in the theft prevention. The car had to be flat bedded to the dealer. They diagnosed the problem and replaced the ignition switch under GMPP warranty. Good luck in finding the problem and getting it fixed.

 

any faults? almost sounds like a bad ignition switch[nothing to do with the column lock].

 

where is the ignition switch?

i dont think its the clutch switch because when this happens i repeatedly push the clutch up and down and that does nothing

 

also how do you diagnose the ignition switch?

 

on the steering column,left lower side

 

I had the exact same problem, but mine wouldn't even try to start. Had to have it flatbedded to dealership and have ignition switch replaced. I'm guessing mine has some underlying cause though, as it has started to happen again with the new switch being only 4-5 months old.

 

so how much did the switch cost then?

 

If I remember correctly, it was just over $400 installed. Of course, this is Hawaii and everything is inflated 400% so it may be cheaper for you.

 

The clutch switch is probably the easiest thing to check, and/or jumper out for testing purposes. You'll find a yellow and purple wire running to it, if you connect those wires together, you've just bypassed the clutch switch and eliminated it as a possibility

If it still doesn't start, you will need a voltmeter and start checking the wires at the theft-deterrant relay (located next to the BCM in the pass. footwell). It has 4 wires connected to it...yellow, yellow/black, red, and purple. The yellow wire comes from the clutch switch, and when attempting to start, should have +12v. The yellow/black wire comes from the BCM, and the BCM provides the ground signal to this wire if the key was read properly.
If measuring between those two wires you get 12v when attemting to start, the relay should pull in (you'll hear it click). If it doesn't, replace the relay.
If the relay does close, and still no crank, check the thick red and purple wires at the relay. The red is +12v at all times, straight from the fusebox, the purple will have +12v when the relay pulls in. That purple wire runs directly to the starter solenoid. If you have 12v at the purple wire, and it does not crank, first carefully inspect the wires running to the starter, they do come very close to the exhaust, and can get burnt or broken...if all that is ok, you will need to replace the starter.


I found the above using the search function so ill start there
i cant seem to figure out where these red and purple and yellow/black wires are
i see the clutch relay but cant get the plug off of it either so i figureed i would just test it at the other wire if i can find it
anyone know where it is?
i took the passenger side kickplate out and can see the giant fuses. I dont know what to look for
when i put the key in i do here a clicking sound by the kickplate but when it stops turning the motor it clicks again, even though the key is still turned to on

is there some sort of timer on the relay that resets it every say 3 seconds?
cause if so then thats why it half *** turns then waits 3 seconds then turns again. so i would be able to say i have a bad relay
do those have to be unscrewed?

 

That helps a little bit.

It is very possible your relay is bad, but it is also possible for a bad connection elsewhere to be dropping power to the relay coil, which would produce the same symptom. There is no timer on that relay...if you apply 12v between the yellow and yellow/black wires, the relay should pull in and close the contacts between the red and purple wires.

As I stated in the text you quoted, the only real way to isolate the problem will be to probe these wires with a voltmeter while attempting to crank it over, and only then will you have a better idea of where the problem may be.

If you're losing +12v on the yellow wire (while trying to crank), suspect your ign switch or clutch switch.
If you're losing ground on the yellow/black wire, the BCM is inhibiting it, likely due to a VATS problem.
If you have a steady 12v between the yellow wires, and the relay still is clicking on and off, your relay is bad.


Here is the location of the theft-deterrant relay (circled in yellow), directly above the BCM:



And a closeup of the relay:


You are actually seeing the base of the relay from this angle. The relay itself is on the backside of that black connector, I believe it simply unplugs.

Also, here is the schematic of the starting circuit:

 

awsome

thanks y2k
i dont think it gets any easier than that . Ill have to go out tomorrow and probe these wires to see what they are doing. Im actually kind of glad i caught this now rather than in june because having your vette not run in march isnt that bad when you live in ohio.

 

I went out and bought a new relay for my car yesterday. It was $23 from Redline Automovtive and its an AC Delco part. I checked and the same part through the stealership is $35. The part number is 12193601. Hope this helps someone out.

 

ok well its not the theft deterrent relay
bought that today for 20$ and popped it in
same deal

its not that or the clutch relay
i pulled it out and bench tested it and it sends the current through when pushed in

sooooo

hmm

i also bought the ignition relay but havent put it in yet because then i cant take it back

its the one that goes in the fuse box in front of the battery. anyone think it might be that?

im wondering if the wires to the starter didnt just burn up or something or come loose

i need to get under there tomorrow

the car cranks for a split second and then nothing
if you hold the key to on it cranks every 3 seconds or so
its not a battery
its deffinately a strong crank

occasionally it does start but cuts out after a few seconds

hmmmmm

 

Ignition switch $77.13 list, part#10308321, .9 hr labor

 

If it isn't the switch as suggested here by others...
Some other suggestions I have are:
Are your battery CABLES good?
Have you cleaned your grounds as discussed in the sticky thread at the top of this forum?
http://forums.corvetteforum.com/show...875&forum_id=1
Can you pull the starter and have it tested?

 

I can pull the starter off thats not a problem
I have long tube headers so its not exactly something im looking forward to.

I dont think its a bad starter. When it does start it dies out like the fuel or spark gets cut a few moments after it does start.

I have the ignition relay i can put that in but what does it do?

Im now leaning towards the ignition switch

Where is the ignition switch ? and how can i test it?

 

breaking news

if this helps I took the new theft relay off and jumpered the red wire over to the purple and i get the motor to turn over
so then i decided to be slick and stick the key in the ignition to the on position while i was jumpering the relay and ....it started

and stalled 3 seconds later

but now i did it again ait got it to start
and its idling now

soooo wtf

if jumper past the purple and red wire then either the yellow or yellow black must be fd up
the clutch switch is workig but maybe the wire coming over isnt?
or the bcm?

i wasnt able to ever get a ground signal out of the bcm at the theft relay

hmmm
will a car run with a faulty bcm?

 

alright F it
I got it started when i did it said pull key wait ten seconds so i did
then i started it again and made it down the road before it stalled and died out

I called chevy and they sent a tow truck to get it.

I told them that it said pull key wait 10 and they covered the tow bill to get it there

they are going to perform the recall and see if that fixes it

 

alright dealership says they have it fixed 215.18 total
said it was a ground wire that was completely loose...? so why 215$
havent seen the invoice yet though
and they also did the recall for me

i bet they are full o **** so well see when i go to pick it up

I bet they saw a wire that was loose and tightened it and then it started
but since its interimitten....hmm we shall see