MX-3.com

hey guys like the topic says..charge light randomly comes on. on highway stop light etc...it goes on and go away sometimes stays on sometime blinks..you get the picture..
so I'm thinking my alternator is going.
I monitor my battery voltage through megasquirt and the voltage is always high like suppose to..never goes down

could it be somthing else beside the alternator ?

Could be the voltage regulator inside the alternator is getting flakey.. that would also result in the charge light coming on..

Tunes67

I got a spare one at one..think I'M going to swap it over. isn't too much of a job

Mine was doing this 2 days ago.. it was the connector to the alternato..it was loose somehow.. i pressed it in and it stopped blinking. These alternators last a loooong time..from what ive seen.

good I'll check the connection

You are low on Battery Fluid... Just top it off an you will be good to go!

That happened to me off and on since last winter, it was my battery...

Rick Johnson wrote:That happened to me off and on since last winter, it was my battery...

my battery is almost new and is a yellow top so I doubt it's the battery

babyblueMX3 wrote:

Rick Johnson wrote:That happened to me off and on since last winter, it was my battery...

my battery is almost new and is a yellow top so I doubt it's the battery

Well, I've been telling people for years how a yellow top screwed up charging systems on two of my cars. Now that I work at Optima's parent company, maybe people will listen to me. I can get a discount on Optimas, and I still won't buy one for myself. Get rid of the yellow top. If you want an Optima, get a red top. Otherwise, look at the regular Exide Orbital battery. I got mine for $85 USD shipped from an authorized distributor. It's great. It maintains its voltage like a ROCK even with the headlights and 800 watt stereo at full tilt.

I keeps it voltage..I watch it trough megasquirt and it doesn't go down a bit..so I doubt it's the battery

lakersfan1 wrote:Well, I've been telling people for years how a yellow top screwed up charging systems on two of my cars. Now that I work at Optima's parent company, maybe people will listen to me. I can get a discount on Optimas, and I still won't buy one for myself. Get rid of the yellow top. If you want an Optima, get a red top.

Exactly! I don't remember exactly the reason why, it's been too long, but it has to do with the way the battery accepts a charge and outputs power.
Correct me if I'm wrong, but this is what I remember:
-Deep cycle need to be slow/trickly charged, they don't like to be quick charged, ie:car alternator
-Deep cycle batteries need to be drained then recharged, they don't like to be "topped up"

When I was a kid, we used to go camping with my parents in a 19ft trailer, and we didn't always need hook ups (power, water, sewage), we just used the battery to power lights and the water pump for the water tank. Well after a few days it would get low, so my dad would hook up the truck and charge the battery, we fried 2 deep cycle batteries over the course of a summer. After that we just got regular batteries and camped for years after that with no problems.

I've seen ALOT of people use yellow tops as starting batteries, but I can't get myself to do it. It's the reason why I run (dual) red tops instead of yellow tops.

My guess is the alternator. This happened to me 3 weeks ago. Had the alternator changed and no problems now.
I also agree with the yellow top comments. My best friends dad owns a tire/battery shop and has for a while. I went in to get a new battery after my alternator fried my old one, and I was ready to get a yellow top when he told me that hes had more people come back in to get theirs taken out then he has sold them. So he set me up with an exide orbital 'purple haze' battery like lf1 said he haad there I think. cost me 60CAD(hehe) and its great. I also know 3 other mx's running them with good results.

The voltage at the battery terminals with the car running should be between 13.5 and 14.5 volts(Correct me if Im wrong). Any higher and it will boil the battery acid away, eventually killing your battery. Also I believe the charge light will come on if the voltage is too high or too low.

I had this happen where I would get the charge light coming on at idle and anything under 3-4k rpms. It would sometimes flicker. I had to replace my alternator but it was the voltage regulator within the alternator causing this.

I,ll try the alternator first...if that doesn't do the trick I'll swap battery

I got a brand new yellow top a month ago..... it fixed my charge light problem...

Deep cycles can be discharged all the way, but it will shorten their lifespan... it says so in the instructions.... they can be charged quickly or slowly like any other battery. A trickle charge is best for all lead acid batteries, but in real life situations it isn't always possible.