Need wiring diagrams (especially starter) for a 2002 Buick Regal that won't start

bighank1

Someone has modified the harness from the Ignition Switch on a 2002 Buick Regal. It wont start. Suspect the Ignition Switch or the VATS detection leads in the Ignition Lock are defective. Removed the Ignition Switch (ALMOST) but found someone cut the thick about 12 gauge wire at the connector to the rest of the car under the dash and ran a brown wire from it coming from the switch thru the firewall and to the front of the car. It is in the last row of connectors at the extreme edge of the Ignition Switch connector. Before cutting into a new switch harness I want to find out where the brown wire goes. I think this is the wire to energize the starter but do not have any wiring diagrams and haven't found any on the internet.

Does someone have either the wiring diagrams for a 2002 Buick Regal or can point me to a URL to get them?

stever

Try bbbind.com for free diagrams (you'll have to sign up but it's pretty painless).

imidazol97

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bighank1

Went to the BBBIND.COM website and downloaded 2 PDF files for a 2002 Buick Regal which said electrical. Did not find the schematics for the ignition switch or starter. Would still like to find some electrical wiring schematics for the starter and ignition switch.

Traced the brown wire which connects to the thick yellow wire at the ignition switch connector. It runs to the starter and I believe it is used to engage the starting motor. Could not find the original wire that went to the starter which I believe someone cut off short. Car would not start and I think that the Ignition Switch is bad.
Could also be the VATS system not recognizing the key resistor pellet.

Looked at 2 different Ignition Switches and cables at Advance Auto. The CARQUEST BWD CS545 switch listed as Exc Floor Console does not have 2 connectors at the switch. It is missing the 2 wire connector I think going to the key removal solenoid. The CARQUEST BWD CS605 switch has both 2 wire leads at the switch end but is listed as w/ Floor Console. This seems to also be equal to the GM 26068757 switch and the AC Delco D1491D or Wells LS927 switches which are also listed as for cars with the floor console. The car I am working on is a Regal LS with the switch on the steering column. Has anyone else changed this switch on a car with the switch on the column? What switch did you use?

stever

Check with your public library online. Sometimes they have Chiltons or other guides available for viewing online.

You may want to check the part at RockAuto.com or other online parts company too. Sometimes they have diagrams that'll blow up enough to make some sense out of them.

imidazol97

bighank1 said:

Car would not start and I think that the Ignition Switch is bad.
Could also be the VATS system not recognizing the key resistor pellet.

Does your car have the pellet in the key that is touched on both sides by the contacts inside the lock cylinder?


or does it have the radio wave transponder embedded inside the head of the key?

bighank1

Have a resistor pellet VATS key. I have already had to replace a lock cylinder on my Corvette which also has the resistor pellet as the contacts that feel the resistor wore out.

Traced the wire spliced into the thick yellow wire coming from the ignition switch. As I suspected it went to the starter solenoid. The original wire to the solenoid was nowhere to be found and was probably cut off short at the wiring harness. I jumpered the brown wire and got a spark but it did not pull in the solenoid to cause the starter to run. I pulled the starter and rechecked with 12 volts to the solenoid. Drew current but would not engage the solenoid. Then I jumped right to the thick braided wire to the starter. It RAN. The starter motor is good but the solenoid is defective. Removed the solenoid and re applied 12 volts to it. If you push the linkage it will engage but it will not engage with just applying 12 volts. Need to replace this. Can get a starter and solenoid at a u pull it junkyard for $20 so I think I will see if I can find one that works.

I still am puzzled why someone would run a wire directly to the solenoid. In a diagram I did find it seems that the wire to engage the solenoid goes thru something else,the neutral start transmission switch and or the VATS OK circuit before it allows the 12 volts to go to the solenoid. Can anyone clarify this?

imidazol97

This is the circuit diagram I find on autozone.com.

It shows the crank voltage goes to a start enable relay that turns on only if the
PCM approves based on reading the chip resistance in the key is proper within
the small error ranges that's allowed.

Sounds like someone just went directly from the start/crank connection to the
starter in your car.

Not sure why the black on white gif shows up as white print on black when
I posted it from Autozone's great help site. Here's link to their site.

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0996b43f/80/24/0a/a5/large/0996b43f80240aa5.gif

bighank1

Solenoid is defective. Went to junkyard and got another. Will try installing and see if it will start the car.
Not sure why someone bypassed the P N switch and the crank relay. Got a good solenoid, When engaged draws only a few amps..Still not sure that the ignition switch can take the current load without using a relay.

Any thoughts on that?

bighank1

Replaced solenoid and car started immediately. Don't know why someone bypassed half of the circuitry to the starter solenoid.