Pontiac Sunfire Doesn't Start After Battery & Alternator Change?

My husband and bother in law changed both the battery and alternator on a 1998 Pontiac Sunfire. It won't turn on. Is there something that has to be reset? Is this some sort of safety feature?

Thanks
Pontiac Sunfire Doesn't Start After Battery %26amp; Alternator Change?
There is no mechanical locking system to prevent you from turning the key to the on/start postion



*if the key drum will not rotate after entry into the ignition it could be that the wheel lock pin is mechanically pressed hard against the locking sprocket. This is a rare condition to come across but it does happen. Try applying turning pressure one way on the wheel and attempt to turn the key. If that fails try the other way. Still not luck? Try varying the key depth in the ignition. Will the key turn back for the accessory power on mode?



*if the key drum will not turn at all and is in the on/start position and you cannot remove the key, try varying the key depth in ignition. A failing keydrum will not always hold the key at the depth required to allow movement. Kind of a partial lock position. IF this is interpreting our latest note correctly and pushing the key in more and backing the key out fails to work try some wd-40.



*if the key drum will not rotate after entry into the ignition it could be that the wheel lock pin is mechanically pressed hard against the locking sprocket. This is a rare condition to come across but it does happen. Try applying turning pressure one way on the wheel and attempt to turn the key. If that fails try the other way. Still not luck? Try varying the key depth in the ignition.



I had a 1996 pontiac sunfire %26quot;burn out%26quot; its ignition switch due to a design defect. I don't know if your year was affected by this.



Some things to check out assuming the car engine turns over but does not start.



*Do you hear the fuel pump run when the ignition is first turned on? Should be anywhere from a a half of a second to two typically. Lower the seat back on the rear seats and see if you can hear a mid frequency hum. If no, repeat with someone else turning the car on while you stand in back passenger side, fuel fill area.



*Someone hear mentioned the ignition coil pack. You can disconnect the plug wires from each plug and test with an old spark plug. One at a time with someone else %26quot;starting%26quot; the engine hold the wire from the thick rubber boot with a spare spark plug in it, connected. Touch the screw thread portion to a ground (metal) strap or bare metal under the hood. If you see a spark between the center of the plug and the metal strip connected below the screw threads then you can be reasonably assured there is spark. This is a good time to make sure the spark plug wire connections are clean from the coil packs to the spark plugs individually.



*There can be several faults with electrical wiring alone that can cause the TheftLock light to pop on and prevent the engine from starting.



Now with the following suggestions are hard to diagnose because the car was electrically dead for a long enough time to clear out any service codes that may have been stored. before the battery was swapped out. A good mechanic, who is hard to find would scan the computer for stored codes. The Sunfire computer systems will turn the service light off after a period of time but still retain the code. Anything along these lines from here on out is less likely but difficulty to diagnose properly without the engine running on its own power. Sensors are non-returnable items.



*If the engine was running particularly rough and sluggish before it stopped there may be a problem with your air intake manifold gasket. Typically problems here are noticeable enough when one cylinder's seal is lost you seek service. If the symptom described here is reminiscent of your issue, you can try holding an unlit blow torch near the intake manifold off of each cylinder where the intake meets the head. If the engine behavior changes and it sounds like it is stumbling, trying but failing to start you have found your problem. Do this test outdoors and a max 15 seconds per spot, 1 minute between each time.



*The Mass Airflow Sensor (typically called MAF sensor) could have an electrical fault internally or along its wiring. The car may have been hard starting.
Pontiac Sunfire Doesn't Start After Battery %26amp; Alternator Change?
is the theft light flashing on the instrument panel cluster after you try to start it? that would indicate a theft deterrent problem. don't panic, leave the key on for 10 minutes after attempting to star it. that flashing theft light will turn off after 10 minutes, then turn the key off, for 5 seconds, and start it. if it is a theft deterrent concern, it will start. if it's something else, well, back to the drawing board.
If you have some mechanical knowledge follow this: see if you have battery voltage at the big wire on the starter. NO- possible fuseable link at the starter. YES- check voltage on small wire with ignition in the CRANK/START position. Now to cont. with the %26quot;NO%26quot; and yes to good fuseable links. Check your battery wires. Both pos and neg. Check the ground wire and make sure it has a good connection. Make sure you have voltage at the battery wire (big one). If yes to those then on to the small wire... If no on the voltage with in crank position the most likely it is the starter switch. Go to the parts store and buy one to see what you have to replace. Most likely it won't be the key switch. Any other questions or help contact me and I will try some more advice. Good Luck..and have fun
battery not hooked up correct or not tightened the cables.......or loose wires on alternator

or dead battery installed

charge the battery


Does it turn over, if not check and see if they hooked up the battery the right way. And check all the fuses, they may have blown one when they where working on it.
not enough info. did it start and run before the husband and bri-law-adventure.
Well if it doesn't start perhaps you should check the starter???
ignition coil