I have a 1998 Monte Carlo LS. I put a new battery in it three months ago. In the last three days I've had intermittent issues with it starting. It will start right up some times and then other times I'll turn the key and get nothing but a hum from the engine. The fan, radio, dashboard, wipers, and lights will come on but it won't start. I put a new starter on and still got the same issue. I'm at a loss here. Anybody got any words of advice?

 

If you don't hear the starter working, then the hum you're hearing is probably the fuel pump in the back (as the engine has nothing to "hum").

Possibly a bad/corroded connection on the battery or the starter. If the starter is not operating, you have to determine why. If it's not cranking, it's either not getting power or perhaps there is a problem between the ignition switch on the starter. Just some rough guesses.

 

Is the hum coming from the rear of the car? If so, it's probably the fuel pump as Jason mentioned. If it sounds like it's coming from the front of the car the starter relay may be malfunctioning.

 

just because you hear a "hum" from the fuel pump doesn't mean that you have a bad starter or relay...there can be other issues...i love it when people think it is this or that without doing some kind of diagnostics smh...best thing to do is to make sure you have CORRECT battery voltage...if you do, then have someone try to crank the engine, while taking a test light or DVOM to the purple wire on the starter solenoid...while cranking, if your test light does light up or you get at least 12.45 volts, then yes, your starter has failed...let's go from there and let me know...LETS DO SOME DIAGNOSTICS, have fun and not guess!!!!

 

If the car doesn't even attempt to crank, you either have an issue with the starter/wiring or the VEHICLE ANTI THEFT SYSTEM, which would be my guess. You can either bypass the VATS or get a new ignition switch and key.

Here's a write up on the VATS bypass.

How to bypass the VATS system in a late model GM vehicle

Good luck.

 

Could you please point out where I said the relay or starter was bad because he heard a hum from the fuel pump? The 2 are unrelated, so I don't know how YOU would come up with such an idea.

I was simply trying to determine if the hum he heard was from the front or rear of the vehicle. Yes, I should have mentioned checking battery and cables (which you omitted) condition first, but it is such a standard part of the routine I overlooked it. In my experience if the battery/cables are good and the hum is coming from the front of the vehicle it is the starter relay. If it is a clicking or ticking sound it is usually the starter. Yes, those are guesses, but so are 99% of the replies on the forum - including your own post. You're declaring that if voltage is present then the starter is bad. That is incorrect. You could see voltage but the starter not energize simply because of a bad ground. Since you forgot to mention checking the cables I guess you're not on top of your game either when it comes to diagnostics. Say it isn't so...