[TheDoug]

Hey all my 89 Sierra wont start. I left my lights on for a few hours by accident. I tried to key start it and the starter turned over maybe 3 times before fizzling out. As this happened both indicators began flashing for a few minutes as if I had put my hazards on (although I believe my model does not have a hazard light feature), then a red light down by the ignition began blinking and has continued to blink for a few hours now. The headlights and electronics are still working which means the battery isn't completely drained. I have tried jump starting it with no luck, I cannot even get a spark when touching leads to the battery and the starter motor reuses to turn over. I have also tried clutch starting it down a hill several times with no luck. All my fuses are okay and I have plenty of fuel. Can anyone help me to figure out whats going on? Thanks in advance.

[Cozook]

Do you have an alarm.. Imobilizer?

[Cozook]

Ignition kill switch?

[Gwagensteve]

You have an alarm/immobiliser. draining the battery will set it into action and it will create the conditions you're experiencing.

[losfer]

if it is immobiliser then it will only cut spark , not fuel like efi cars (because mechanical fuel pump) .
I would try this , there is a black wire with a white stripe going to ignition coil + . power this wire up , then simply bridge the positive terminal of starter and starter solenoid (black wire with a yellow stripe going to spade terminal on solenoid) with the ignition on and it should start .

if this works , then its as simple as finding the black wire with white stripe under the dash where the immobiliser (if equipped) is spliced into. and the black with yellow stripe that goes to behind the ignition barrel.

from memory the black with white is coil/meter in the fuse box , do the dash lights illuminate ?