Charging issues

[Willard]

Ok, so due to problems I was having awhile ago, my explorer has basically a completely new charging system. It has new cables, a new alternator, and a new battery. For the most part everything works fine, always starts great, battery works just as it should.

However, I have a problem with charging sometimes. When I have the headlights and blower fan on, and am stopped and idling in gear (such as at a stoplight) the voltage drops. If the heater fan is on high, it will be enough to dim the lights. I have no other supplementary power items to speak of, except for a little stereo work, which isn't the problem. If I turn the radio off when this happens it has no affect.

So I'm wondering why this is happening. Everything seems to be working fine, it just can't handle the load when I'm stopped. In gear it idles just above 500rpm, where it always has. It runs great.

I'm not sure what I could check that would be causing this. It seems like something is using too much power, or something is holding it back from charging like it should. But with the main components of the charging system all new, it just doesn't make any sense. Battery is the biggest stock one I can get, I believe its 1100 CCA.

Any ideas?

 

[marragtop]

Did you have this problem before you replaced the batt and alternator? If not, did you get the 95amp or hte 130amp alternator? Also, are you sure all the wires are hooked up correctly? I suggest you meter what your output is directly at the alterntaor with the motor running. It should be around 14v.

 

[boggs1227]

does not the alt start to put out a charge at around 1200-1500 rpms? mine does this a little when i accessories on at night.

maybe upgradeing the limited's alt thats 130 amps....but other than that it's just the nature of the system ...i would not worry to much about it .

 

[Willard]

I did have the problem before replacing everything, although it was worse and had issues while driving even. I also had the charging light at which point I knew my alt was biting the dust.

It does charge fine even at around 750rpm or so. If I put it in park and the idle goes up a little it is usually alright. I can also sit at the stoplight and just touch the throttle to bring up the rpm's and it is fine.

I guess I just assume that the stock system should be able to support the stock accessories without any problem. In my experience dimming of the lights when using the stock accessories heavily points to a problem somewhere. At the same time, the truck is 15 years old with almost 220k, I guess I shouldn't be complaining.

 

[TedJ]

Mine does the same thing.... its just normal I suppose :scratch: Alternator just can't output enough current to keep up with the heater blower on any setting above 1 or 2 and the headlights. Bringing up the RPM about 100 higher than hot idle brings the voltage right up. I usually just lower the fan one notch if its bothering me...

 

[PCTechman]

I solved my low output at idle problems with a smaller pulley which allows the alternator to run faster. The problem I was having was dim lights when running heater/defroster or A/C when in traffic. The other choice would be to install a high output alternator. The pulley is the cheaper way to go and it's been working for me. Check out this link for more info on pulleys/alternators:

http://www.alternatorparts.com/

PS I bought the smallest pullet available and the next to the smallest, I was concerned it would not allow enough tension on the idler for the serpentine belt. I installed the smallest one and it's been OK for over 2 years now!

 

[Willard]

Bumping this thread back up. The issue is getting worse and I would like to figure it out this time.

Now when stopped at all, with any or none accessories on, the voltage drops to the point of being noticeable. Windows are slow, wipers are slow, blinkers are even slow. With the headlights on it doesn't change much. Sometimes the voltage doesn't come back all the way until I accelerate to around 1500 RPMs or even more sometimes.

I have made a new ground from the body to the motor, motor to the frame, and frame to the body to hopefully eliminate that being the issue.

All I know is the issue is bad enough now it cannot be considered normal, it shouldn't be doing this. I have also verified the voltage is the same at the alternator and the battery when running. I haven't put a multimeter on the voltage regulator yet to check that, but I feel I've done everything else. Any ideas?

 

[imp]

Poor or intermittently high resistance connection in the low-current wiring concerning voltage regulation.

As a start, I would find a new alternator harness with the connector(s) which hook onto the alternator (Ford Dealer might have a patch kit for this), clip off the old wires a foot or so away from the alternator, and splice in the similar part of the new harness. If done, be aware that splicing MUST be done well, connections crimped and SOLDERED, and put some NoAlox (available at electrical suppliers, like Graybar, CED, etc.) on the connections at the alternator.

Just a thought. The problem has existed long enough! imp

 

[TedJ]

As a start, I would find a new alternator harness with the connector(s) which hook onto the alternator (Ford Dealer might have a patch kit for this), clip off the old wires a foot or so away from the alternator, and splice in the similar part of the new harness.

This sounds like a fix for the old 2G alternator's plug in wiring connector, which tended to loose contact and melt.

The 3G series in the explorer uses the standard ring terminal and stud connection for the output.

Now back in my post from Feb 2009, I mentioned that my alternator could not keep up at idle under heavy loads. Since then, that condition kept getting worse, and with the A/C and blower on while driving (even at 2000rpm on the highway) the voltage was "too low". It was still charging but was getting more and more marginal.

I ended up replacing the alternator and battery cables. I don't think the battery cables were a problem yet, but they were showing signs of deteriorating.

I replaced the alternator with the HD 130a 3G series large case, internal regulator from alternatorparts.com

So far it's been awesome, the voltage stays in one place even at idle with lots of loads. It is heavier and (somewhat) larger than the original, and uses what looks to be good quality components. I didn't tear it down, but I'd assume that 180,000 or so miles the original alternator had just worn out.

 

[Willard]

If I had money for a nice new alternator I would go for it. Problem being, I don't have the money, and honestly I only plan on having this truck for a couple more years max. I need to upgrade to a newer vehicle soon.

After much more searching and reading through my haynes manual though, I have come to another possible solution. The wire that goes from the regulator to the gauge and through to the ignition switch may be the culprit. If for some reason full voltage is not passing through this wire with the key on, the regulator will get the wrong signal and subsequently not put out enough from the alternator to keep things going good.

Hopefully tomorrow or sometime this week I will be able to do a little troubleshooting to see if I have a problem with this wire, the circuits it passes through, or the ignition switch. If nothing comes of that, I will check the voltage regulator and the alternator and see if I can get any kind of results.

Thanks for the replies thus far guys.

 

[TedJ]

Any new updates? What makes you suspect everything else besides the alternator?

 

[Willard]

Not really much to update, haven't had the chance needed to mess with it much.

What makes me suspect stuff besides the alternator is a couple different reasons. One, the alternator is relatively new. I know, getting one from a parts store it may not be good quality, but I don't think that is the issue here. The alternator charges fine once I get over 1500 RPM's or so. Plus, everything does work, it just doesn't charge to my liking at lower RPM's. Secondly, this thing has almost 240k miles on it and is 16 years old. I have had more than one strange electrical issue with it. Wires and connectors get old and don't do what they should anymore. The only other thing I've thought about besides what I already mentioned is the voltage regulator. But that will come only after I confirm it's not one of my other suspicions.

I have done a little testing though so far, and one thing is raising an eyebrow for me. I removed the ignition switch to make sure everything was connecting fine within it. I think this may be part of the problem. When in the accessory position, it definitely connects the battery to the accessories like it should. However, when in both the run and start position, I couldn't get any continuity at all on my multimeter. This leads me to believe the switch isn't connecting well. Obviously it works, otherwise the truck wouldn't even start let alone run. But I don't think it's connecting well.

I will either tap in another wire that is only on with the key to the I terminal on the alternator and see what happens, or I will replace the ignition switch first. The switch is only $15, and so when I have a little cash I may go that route. Plus it has exhibited signs in the past of getting old. Sometimes (although it hasn't done this in awhile) I will go to start it and when I hit the start position with the key there is another half a second or so delay before the starter actually engages. It is not within the starter itself, because I cannot hear the solenoid engaging when it does this and the starter is only a year or so old anyways.

 

[TedJ]

If the iginition switch will run the truck, then your multimeter should be indicating continuity. I might try testing that again. It is cheap so probably no harm in changing it but I hate changing parts that are still good.

I give you credit for doing the due diligence and actually checking and doing diagnostics, because so many people don't and just blow cash changing parts needlessly.

I will say though, I have had multiple very bad experiences with rebuilt alternators. They do the bare minimum to give you something that might not even work once you install it. Three of the alternator failures I have had or came close to (really low output but it got me home) all started with constantly decreasing output in the low RPM range. So, maybe its biased by my experiences but I think your alternator is probably not doing so well.

Your best bet might be if you could find an old school guy who actually rebuilds alternators himself, try looking under auto electric in the phone book or calling people who fix/restore vintage cars, they might know someone because the alternators for those cars are sometimes hard to find through the "regular" places.

 

[Willard]

That's a good suggestion for a rebuilt one. I kind of wish I hadn't waited this long so I could just return the alternator I have and throw in a better one, but it's too late for that now I'm sure.

I do know of a shop I might be able to have rebuild it for me, I'll have to check their prices. But perhaps before I do that I should pop the alternator out and run it to Auto Zone to see if it tests bad for them. I know it may test good and still not work right, but that would help give me some sort of answer.

My biggest problem with this whole project is money right now. I don't have a whole lot at the moment, and I really don't want to invest much more in this truck at this point. I'm not planning on keeping it forever, so I'm just trying my best to make everything work better without a huge investment.

 

[TedJ]

Double check and make sure your rebuild does not have a lifetime warranty. A lot of them do because they are so ****ty that they want to keep you happy somehow. You might need the receipt though.

 

[Willard]

Thanks I will check that.

On another note, I went ahead and replaced the ignition switch today since mine showed to not be working so well anyways. It didn't do squat to the charging problem, but for some reason my ABS light went off and it works now. The codes I had already pulled on that wouldn't seemingly be affected by the switch, but maybe something wasn't connecting right.

Either way, at least I fixed one of my problems, even if it wasn't the intended one.