85 chevy silverado engine wont start

2 cars, which one died
never jumper cable backwards (Plus/minus) or boom , electronics blow to H3LL. sorry if happened.
or
if car 1 battery is dead and will not crank. OR LOOSE RUSTY LUGS.
we jumper it with running 2nd car and noW car 1 cranks and runs.
BUT....?
now if cables are pulled (jump pair)
and car 1 dies, then car 1 battery or alternator is dead.
we test the battery first, we charge it and load test it (2 tools)

IF FAILS this test the BATTERY IS USELESS.
OR GET the BATTERY CAR 1 TESTING IN CAR STORE FOR FREE.
OK BATTERY GOOD BUT ALTERNATOR BAD.
NEW BATTERY STARTS THE CAR, AND IF ALTERNATOR IS GOOD
THE VOLTAGE ON THE BATTERY IS 13 TO 15VDC, BeLOW THAT , THE ALTERNATOR IS BAD. OR ITS FUSES are BLOWN.
OR BELT TO ALT IS LOOSE OR FELL OFF.

best is own a battery charger.
and if battery reaches, 12..6vdc rested it may be a good battery.

It can. Have an autoparts store test alternator. This service is usually free. Could test battery as well.

From the ignition switch there is a yellow wire that is for the starter. probe it when trying to start. If you have no voltage replace the switch. Also, I believe there is a fusible link in the wire by the starter. It will be a different color than purple. Probe on the back side of it to see if there is voltage at start up. If so, replace with the smae color link.

Is power getting to the ignition switch? Do the warning lights and gauges come on when key is turned to on? That would verify power in and power out at the switch. Then you would need to check the start circuit. A single start wire comes out of the switch, the signal travels through the neutral safety switch and a starter relay and then to the starter solenoid mounted on the starter. Solenoid closes contacts so battery power can operate the starter. If new starter doesn't work, power has been lost between the ignition switch and the starter.
If no power to the ignition switch check maxi fuses, all fuses in fact, and possibly a fusible link from the battery that may be the feed for the switch.

Code 11 means no distributor reference signal detected during cranking. Check the circuit between the Distributor and PCM (computer). Also, keep in mind the following operations/tests apply to these relays only: Automatic Shutdown (ASD) , Fuel Pump and Ballast Bypass. For operations/tests on all other relays refer to the appropriate test.

OPERATION:
The relay terminal numbers can be found on the bottom of the relay.
Terminal number 30 is connected to battery voltage and can be switched or B + (hot) at all times.
Terminal number 87A is connected (a circuit is formed) to terminal 30 in the de-energized (normally OFF) position.
Terminal number 87 is connected (a circuit is formed) to terminal 30 in the energized (ON) position. Terminal number 87 then supplies battery voltage to the component being operated.
Terminal number 86 is connected to a switched power source.
Terminal number 85 is grounded by the Engine Controller.

TESTING:
Remove relay before testing.
Using an ohmmeter, perform a resistance test between terminals 85 and 86. Resistance value (ohms) should be 75 ±5 ohms for resistor equipped relays.
Connect the ohmmeter between terminals number 87A and 30. Continuity should be present at this time.
Connect the ohmmeter between terminals number 87 and 30. Continuity should not be present at this time.
Use a set of jumper wires (16 gauge or smaller). Connect one jumper wire between terminal number 85 (on the relay) to the ground side (-) of a 12 Volt power source.
Attach the other jumper wire to the positive side (+) of a 12V power source. Do not connect the jumper wire to relay at this time.

CAUTION: Do not allow the ohmmeter to contact terminals 85 or 86 during these tests. Damage to ohmmeter may result.

Attach the other jumper wire (12V +) to terminal number 86. This will activate the relay. Continuity should now be present between terminals number 87 and 30. Continuity should not be present between terminals number 87A and 30.
Disconnect jumper wires from relay and 12 Volt power source.

If continuity or resistance tests did not pass replace relay. The Powertrain Control Module (PCM) and connector are located in the engine compartment, mounted to the inner fender, next to the air cleaner housing (click image fo zoom).
DTC 11 - No reference signal during engine cranking. No camshaft reference signal was detected during engine cranking.
DTC 12 - Battery disconnect. Battery input to PCM disconnected during last 50 key starts.
DTC 42 - ASD relay control circuit. An open or shorted condition detected in the auto shut down relay circuit.



Hope helps.

You should probably check the timing. It's not uncommon for Chevy's to jump time when they are shut off. Bring the engine around so the timing mark on the bottom pully is at 0 and lift the distributor cap. The rotor button should either be under the #1 plug wire( front wire on driver's side) or 180 degrees away from it. If it's off 180 then turn the engine over until the 0 lines up again. The rotor button should line up then. If it doesn't then turn the distributor until it does and try to start it. It should start there but you will still have to change the timing chain and gears.Hope this helps.

Could be the cables or the starter. Remove the starter and have it tested.

Replace the ignition module.

Sound like you have a bad alternator, poss bad battery too.If you can jump start it with a volt meter check voltage at battery should have above 13.5 volts, do this after you unhook jumper cables and engine running.If bad voltage reading replace alternator make sure you charge battery before starting engine with new alternator or it could damage alternator.If good voltage have battery check.Hope this helped.

Go to autozone.com and register,and you'll be able to access their online repair manual.It contains everthing you'll need.