98 Suburban Starting Trouble

**mounty95** · 08-19-2009, 09:33 PM

I have a 98 Suburban that this morning would not start and had to jumped. So I take it to Advance they test the battery tell me it is good (purchased 3/08) but low on charge. Recommendation was to check starter and alternator. So I remove starter take it to Advance they tell me it is fine so I put back the starter and do same thing with alternator. Again they tell me it is fine and charge my battery with their charger (took 32 minutes). So I put everything back the way I found it and it seems to start up without issue. So now I don't know what to do. I guess the test may be whether I can start it in the morning as easy as I started once I replaced all the parts. Any recommendations or guidance would be greatly appreciated. I just recently replaced plugs, wires, distributor cap, rotor, air filter, fuel filter, and bank one pre-catalytic converter O2 sensor all in an effort to pass MD Emissions testing. Everything after those replacements was fine but now this seems to be a new issue.

Thanks for any guidance that can be lent to this perplexing issue.

**bill190** · 08-19-2009, 10:54 PM

This is just like a cell phone. The cell phone has a battery. And you need to charge that battery with the plug in adapter or the battery will go low and the cell phone will no longer work.

Same with a vehicle. You have a battery. The alternator charges the battery.

If the battery is not being charged, then battery will run down and no longer work to start your vehicle.

The battery should be 12 something volts with just the ignition on and not started. Then 13/14 volts after starting and the alternator starts charging the battery.

Alternators can stop working when hot. Or stop working when rotating fast. When they "tested" your alternator, did they place it in an oven for a heat test? Did they rotate it fast when testing?

Check this with a multimeter. How to use a multimeter...
http://www.google.com/search?hl=en&s...imeter&aqi=g10

Some vehicles have a voltmeter on the dash. If you have this, watch it when driving, especially on very hot days or driving at faster speeds. It should read 13/14 volts. If 12 something volts, there is a problem with the alternator or its associated wiring.

You can get your own battery charger for not too much to keep your battery charged while working on this problem. These will indicate when the battery is fully charged.

If you drive home, connect the battery charger, and the battery is fully charged. Then the next morning the vehicle will not start and the battery is drained, then you have a problem with something staying on and draining your battery. Like a radio or maybe an add-on accessory.

Use an amp meter to test for this.

**MrShorty** · 08-19-2009, 11:22 PM

As irritating as it is, I've had a battery do this to me, and test ok when it was going out.

Another thing you might look into is if there is some parasitic draw draining your battery. A relay sticking closed or something like that. 1st step in this test would be to disconnect a bettery cable, put an ammeter in series, and see if there's any current flow with the key off. Anything more than several milliamps (for the computer and radio memories) would be excessive. Make sure you watch it for several minutes to account for things like a fuel pump shutting off or the dome lights.