Engine will not crank over?

GM redesigned their starters and generators for the '87 model year. The field coils are gone in the starters. They use permanent magnets now that are glued to the housing.

When you hear a single, rather loud clunk from the starter each time you turn the ignition switch to "crank", the real common cause on other brands of starter are burned copper contacts in the solenoid. This always starts out as an intermittent problem and gets progressively worse over weeks and months. The starter will eventually crank after cycling the ignition switch repeatedly. GM solenoids are not known for that problem, but two other things commonly happen. One is the solenoid housing warps, then the metal plunger can't move far enough for the contacts to turn on for the motor. A potential clue to this, if you can keep the starter from engaging, is to connect a wheel-type battery charger on a mid-level charge rate, THEN try to start the engine. If that works consistently, it's because the higher voltage makes the solenoid's magnetic field stronger, so the plunger can slide through the warped area easier. That also instantly proves all the rest of the circuit is working.

A second problem can occur when the starter is hit with a hammer, like we used to do to get an intermittent one working. That is very likely to break the bond on the magnets. If a magnet sticks to the armature, it may try to spin but it will crank too slowly and with excessive noise.

Hello,

It sounds like the starter motor is going bad. To be sure this guide will help you change for power at the start solenoid to confirm the failure. There is also a starter relay that needs to checked as well.

https://www.2carpros.com/articles/starter-not-working-repair

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Here is the starter wiring diagrams and the relay location so you can see how the system works. Check out the diagrams (below). Please let us know what happens.

I think I know what the problem is, and it is very simple. Remove the battery terminals and properly clean them. When you replace them, make sure they are clean and tight. Also, make sure the neg terminal from the battery to the engine block is clean and tight too.

This may sound too simple to be correct, but it is the most common cause of what you described.

Try it and let me know what you find.

Joe

My first suspicion is an intermittent neutral safety switch that fails based on its temperature. To check that, remove the starter relay from its socket, then use a test light to see if 12 volts shows up on one of the terminals in the socket when the ignition switch is turned to "crank". If you can't find that 12 volts, try again after shifting between "park" and "neutral" a few times.

Another problem GM had with their redesigned starters was the coil of wire inside the starter's solenoid housing would warp, then the plunger would drag and fail to move far enough to turn on the high-current contact. A potential clue is sometimes the starter will work when you jump the battery with a battery charger or from another vehicle with its engine running. The higher voltage gives the solenoid a little more strength to overcome the dragging plunger. That warped coil gets worse when it is hot. That's what leads to the failure to crank when the engine is hot.

The objective of the security system is to prevent theft. Do you see all the lights that normally should come on. If so start checking the ignition switch and starter solenoid.

Are you getting power to the starter?

Check to see if there is power to it. If there is, something is still wrong with the starter. If there is no power, then we need to work backwards.

One of the wires may have burnt as it was recently changed. Or there may have been a fusicle link that screwed up. I'm sure the guy who put it in guarantees his work if he is reputable and will fix it at no charge.

Check to see if the starter gets full power when this happens. It may be a bad starter or a relay. But checking will tell you either way. Mine did the same thing and it turned out to be starter.

Hello, I'd look at the starter relay, power distribution center under the hood, check for voltage. Two of those terminals should be hot, with the key in the crank position.