04 X2 with small charging problem

Hi there, I'm having a small problem with my electrical charging system and was wondering if someone could help. My volt meter on my dash is showing 12-13 volts instead of it's typical 14. I've scraped the terminals off of both batteries (Perko and negative terminal on the block too) but it's not charging anymore than 12V at idle. When I give it some gas it'll go up to 13, but never more than that. If I idle for more than 2 minutes, the battery alarm comes on. Can anyone point me to the next logical spot to check? Thanks.

Check the belt. Make sure tension is good and that it is not glazed. Check your positive and negative lead off the alternator. Check the connections at the starter as well.

good call on the belt, Brett, didn't even cross my mind. Haven't checked the alternator but have ensured the started is clean. I'll check the belt/alt tomorrow.

Measure the voltage at the alternator and then measure voltage after the battery. You might have a couple bad cells. What voltage does the battery rest at while the boat is not running. Standard for a running alternator should be 13.8-14.4. Battery should rest at 12.5-13.2. A battery that rest at less than 12.0 is considered dead. If you battery rests at less than 12 but it on a charger overnight. 2 or 3 stage smart charger is preferred or a 2-5 amp trickle charger. You will need a Digital Multi Meter (DMM) or volt meter to do these tests. If you do not have a DMM you can get a very basic one at your local autoparts store or harbor freight for $15-30. A very helpful tool that anyone can use. More advanced DMMs run over $400.

It rests at 12-12.5V. I haven't tested technically with my Fluke to confirm that it's over 12. I have two batteries and both report the same at the meter. I'll grab the Fluke and check it out tomorrow. Thanks!

Post your question on tmcowners.com, you'll get plenty of advice there and there are some certified engine nuts there as well.

I had the same problem - the positive lead fell off of my alternator. The boat ran solid for 2-3 hours that day on just the battery!

I wish my problem were that easy, but I checked it out tonight and the positive and negative leads were fine, no corrosion and were tight against the bolts. It's only putting out 12.8 at the alternator. The batteries both are resting at 12.5. I pulled off the negative lead on the block and brushed it off because there was slight corrosion on it, but no luck... still pumping 12.8. The belt seemed tight enough to me, but admittedly, I'm no mechanic. I'm wondering if it's an alternator replacement....

do you have an isolator? have you check connections there? take readings at the iso. to see if you are losing anything there.

The belt should be tight but have a tiny bit of give when you push down on it. Maybe a quarter inch or thereabouts. Doesn't really sound like belt tension is your problem though...

(Message edited by jtnz on April 15, 2008)

That is very very low for an alternator to be putting out. I would take it off and take it in to have it tested or take the boat to a reputable repair shop.

how old are your batteries and what kind are they ?

I had the same problem turns out the alt was bad I agree take you alt off and take to get checked.

thanks for all the suggestions. I'll be pulling it off tomorrow night to have it looked at.