The problem with my suburban was I would turn the ignition off and the starter kept turning the motor over. Then I changed out the ignition lock and ignition switch. When I went to put the negative cable back on the battery, the starter still runs with the ignition lock in the lock position. I would appreciate any help you can give me at this point. Thank you. Robert Ball
Stuck starter solenoid. 1987 was the first year for GM's poorly redesigned generator and their new starter design. The coils of wire can warp and cause the plunger to stick. Most people would just replace the entire starter but you can replace just the solenoid. The clue is it will still crank the engine after you remove the starter relay. If the ignition switch was the problem, the cranking would stop when you removed the relay.