Been fighting with a grid heater issue (or so I thought) lately. Had a prior post about it. Lights would dim/brighten, relays would click on/off, grid was getting hot but the gauge would show a constant discharge until the grid was finished doing it's thing and then it would move on over to the charge side. Not really a huge issue....until tonight!!

On my way to work I hear "DING" and look down and see the check gauges light was on and volt meter was pegged all the way to the left.....no charge at all. Lights started dimming and the air dog fuel pressure went from 18 psi down to 10 psi.....running strictly off battery power at this point. Make it work, shut it off and let it set a few minutes, start it back up and everything is back to normal. Anyone ever had this problem before?

 

Came home this morning from work and so far so good...everything is still working properly. I think I might be having an alternator issue. I know the older ones either worked or they didn't. These newer ones I'm not real sure about. Can they have intermitent proplems? My truck is 9 yrs old and I've never experienced the check gauges issue! If the alt quit charging like it apparently did last night, would that cause the volt gauge to peg all the way over to the left? I'm just trying to narrow things down so I know where to start.

 

start by cleaning battery posts on both batteries, then check again, as battery charges the right battery, then a balancing voltage of both batteries.

 

When my alternator went in the '06 it did the same thing... a couple of weird occurances and then fine for a month or so... and then it just died.

 

Battery posts are very clean...no corrosion. The driver side negative cable end leaves a lot to be desired as it's almost eaten away from the acid from the factory battery. It's been like that for about 3 years and never given any trouble.

I'm still leaning towards the alternator fading out on me. If I take it off and have it checked would they be able to determine if somethings wrong with it even though it's working (for right now) anyway?

 

Had the alternator rebuilt yesterday. For $57 I couldn't pass it up. Very reputable shop as that's all they do is rebuild starters and alts. Installed it hoping for the best....no such luck. Volt gauge still showing discharge until the grid is done.

Now I'm leaning towards either something is faulty with the relays or the grid itself. How would I go about checking these two items for problems. I'm about half dumb when it comes to circuits and ohms and flux capacitor type things but give me a wrench and I can R&R a bunch of things.

 

Remove and clean the corrosion from each of the cable ends, including the battery terminals. Use a wire brush or battery terminal cleaning brush to clean the cable ends and battery terminals. Re install and tighten the terminals and remember(ground cable off first-last on). I highly recommend replacing that drivers side cable as the acid will creep into the stranded copper wires and cause problems. They are no longer on national back order from Dodge. Does this tell you something?

Be sure to clean all of the grounds that connect to the frame and body as well... this is very simple to do and may save you from throwing money at it.

 

If it's totally kicking off, I would lean toward a bad relay (check the big fuse box under the hood) or a bad ground. Did you check for any codes?

 

No stored codes at all. I disconnected the feed wires to the relay but left the trigger wires attached and started the truck and I hear the relays clicking on and off but it seems to me like the grid is now cycling faster than it used to....like every 3-4 secs, on/off on/off.

AARRRGGGG . I hate trying to figure out electrical issues.....

 

While you do have another issue, the volt meter not bouncing may be normal. Has it always bouced until recently? Or any recent software upgrades, tuners, etc?

The volt meter is fake, it's driven by the ECM and not battery voltage. Depending on the model year and flash it may or may not bounce, my 05 shows about 12V during the entire grid cycle even thou the voltage bounces correctly between 11.5 and 15V, my dad's 06 bounces with the grid heater.

 

Uhhhmmm....replace that

 

What he said!!

The ECM uses the voltage at the alternator and passenger battery in conjunction with the temp of the drivers battery to determine the proper charge rate. If the drivers battery has a faulty connection it's easy to fry the batteries or alternator, or both.

 

The gauge has always bounced with the grid cycle up until a couple weeks ago. The cable end is one of the things on my to do list...it's just funny that if that's the problem, why has it taken 3-4 yrs to show up? I'm not saying that's not the problem, maybe it's just that simple , but it's just wierd that all of a sudden I'm having this issue when nothing has been touched on the electrical side of the truck since new....aside from the new batts last year. The cable end was noticed about 3-4 yrs ago if my memory serves me right.

 

You said it yourself that the cable is almost eaten away. Well, electricity can't travel if it has no conductor Electricity takes that path of least resistance. A corroded cable offers a lot of resistance. At the very least pull that cable and test the resistance. I'm almost thinking that if you pull that cable out of the truck it might fall part in our hands, especially under the sheath where you can't see. Even if you were able to clean the exposed end with the clamp, battery acid seeps inside the sheath and keeps doing damage because you can't clean it out.

My logic if it does solve your problem to change out that ground cable: The corrosion that has been ongoing for the last 3 or 4 years has finally deteriorated the cable to the point that the resistance in the cable is high enough that's it's triggering the low voltage threshold for the components or circuits that are wigging out.

 

You mentioned that the cable end is almost eaten away. Get a new cable asap! As I mentioned earlier. In order for that cable end to be eaten away,the corrosion must have enveloped the connection and been
neglected for sometime. The result being,the copper cable strands beyond the cable end have become corroded to the point where it is contributing to or likely causing the issue.

Both Shorts and AH64ID have provided you good advice. As far as that left side negative cable end.. they are no longer on national back order. The part number is 56045770AC and lists for 108.13;however,should be available for 80.50 if you have a good repoir with your local dealership.