2008 A1R with 260a charging questions

Currently has a brand new N3221 voltage regulator (2012 vintage I believe - was new in the box with papers). The truck had a 2013 regulator when I picked it up in Houston. It died about 100 miles from Portland - 2600 miles into the trip back. I put in the brand new spare and drove the last 100 miles home without problems (other than the blown up air compressor - a story for another time - check your dryer cartridges kids). I did find some loose battery terminals after I got it home. All of those are fixed.

Start up the truck and both voltage gauges go to green (28v and the 14v gauge usually reads about 13.5v).

Drive the truck around - a couple miles or so. Gauges go to 24 and about 11.5.

Turn it off and immediately restart - gauges go right back up to green.

Is this intended operation for the 260a alternator and N3221 voltage regulator? I can't find any TM's that are applicable - anyone know of any?

Thanks!
Rick

I had the same issue....drove me crazy looking for a "sophisticated" answer..... ended up being lose alternator belts... all has been good ever since

BERZERKER888 said:

I had the same issue....drove me crazy looking for a "sophisticated" answer..... ended up being lose alternator belts... all has been good ever since

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Well..... that would be excellent but this is a C7 truck with a serpentine belt. Looks to be in good shape and I don't have any reason to believe it's slipping.

I've located the Niehoff troublshooting docs and I have a few things to check like the connections to the LBCD, and the 24v supply to the regulator.


Based on the docs it looks like the regulator might be sensing a disconnect of the batteries from the LBDC and going into OVCO (over-voltage cut-out) when the voltage spike's. Only seems to happen when I actually drive the truck (either due to the movement or the higher RPM)...... I'm going to go over all the connections especially at the LBCD.

ah yes..C7.. serpentine belt...good luck..!

Do all the dash lights work when you do a lamp test? If the LBCD was detecting an alternator overload(it monitors the field circuit on the regulator to determine load) and disconnecting, it will light a dash light. The alt should be able to deal with a disconnect without locking out in over-volt though.

The way to determine this or if it is perhaps something else is to stop without shutting down when the voltage drops, and lift the cab enough to see the lights on the regulator. It could also be that something is interrupting the alt control circuit and simply shutting the alternator off… in which case you will see no lights on the reg… there is also a status LED on the LBCD box itself…

I have performed a lamp test and all the lamps work (and all the lamps are populated). I don't get any indication on the dash lights - just the two voltage gauges read battery voltage. Which indicator lights up in response to a LBCD overload?

I'll go for a drive tomorrow and note the lights on the VR and the LBCD. Hopefully I'll have no problem replicating the problem. Lately this has happened each time I go for a test drive.

Thanks!

I think there are 2 lights, one is battery disconnect and the other is alt or charge failure?

Tentatively I believe the issue is resolved.

The LBCD terminals were NASTY. Most especially the lowest one, which is the 12v batt connection. It looked like either mud wasps or capacitor electrolyte leaking...... Also the top and the bottom studs are slightly loose in the housing of the unit.

At any rate I cleaned everything up, ran a die over the studs, replaced the nuts and lock washers with new, and put dielectric grease (Dow Corning Molykote 111) on everything. I went on a longer test drive than it's ever taken to get an OVCO and nothing happened. I further let it idle for another half hour just to get everything warmed up proper and the gauges were solid on 28 and 14.

The Niehoff troubleshooting tree for the Over-Volt Cut-Out (OVCO) says to replace either the regulator or the alt itself. Makes no mention of checking connections with the N2003 LBCD if so equipped.....

Check your connections - ALL of them - if you run into this behavior.

Rick

Today I got in a 20 mile test drive and can confirm that the over-voltage condition has not re-occured. So definitely if you run into this behavior you need to first inspect, clean, and tighten all battery and ground connections - especially the LBCD that is located behind the cab - the connections are accessed with the spare tire crane lowered.

Rick

I got a chance to test out the original 3221 voltage regulator that came on the truck (2013 vintage), as well as an ebay one (2010 date) I picked up cheap and both function normally now with proper connections. So I believe all the problems from the beginning stemmed from corrosion and poor connections, as well as driving the vehicle to a colder climate (Oregon) than it had experienced - truck was built in TX, went to Kuwait till end of 2009, then was in El-Paso with the USDA till it was bought and driven to Houston around 2019 with only about 2,000 miles on it at that time.

I was very fortunate to make the 2700 mile trip without serious incident.

WELL...... the over-voltage cut-out on the 28v side has returned - did it to me once yesterday and then once today. It seems less frequent though. Today it happened once shortly after I started driving. I shut it off and restarted it (literally at a stop sign) and it remained in the normal charging range for the entire rest of my 20 mile test drive.

I got a replacement LBCD with excellent looking terminals and when prepping it I noticed that the inner nut on the stud actually will unscrew from the stud - did not notice this on mine and two of my terminal studs are broken free from the epoxy so I'm going to swap it out and see what that does.

If anyone else has suggestions - I've been chasing electrical gremlins in general.....

The driver's side headlight turned up dim on Saturday and the parking brake warning lamp would go out every time I turned on the headlights (even though the parking brake was set). I traced these issues to a completely disconnected ground wire inside the washer fluid tank box under the driver's door. That ground fixed the headlight and the parking brake warning. Pump wasn't hooked up either but connecting it does not result in it working - could be bad though it looks pretty homely - have not tested the pump yet or for power. After connecting the ground and the pump there's no more headlight issues.

The horn does not work. There is no power to either lead when actuating the button, and this is with headlights on or off.

Rear passenger turn signal does not function. Have not determined if this is due to a bad (LED) tail light or not - hopefully just a bad unit. Driver's side works fine.

Windshield wipers don't park when turned from full speed to intermittent, and intermittent mode doesn't always function unless wiper is parked. Problem seems intermittent also..... wipers are EXTREMELY intermittent except when intermittent is not selected.....



Working through the issues. If anyone has suggestions or just a tissue it would be appreciated.

Rick

Well lights, wipers TS and horn all go thru the column switch…

Ronmar said:

Well lights, wipers TS and horn all go thru the column switch…

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I have considered this - the turn signal on the passenger front works but the passenger rear does not so switch seems unlikely? The switch definitely could be the problem with the horn and washer motor though. I have pulled up the diagram for the A1 (but not the A1R - don't have) and I'm hoping I can test the output of the column switch to the horn and washer leads to indicate if either are being sent any power.

My biggest issue is definitely the over-volt cut-out though. It definitely occurs with multiple voltage regulators and at the moment seems to occur once after the first drive, and then does not come back. I'm considering wiring in a toggle switch to shut off power to the E terminal (or toggle power to the K11 relay) of the regulator so I can restart the regulator on the fly without shutting down the engine.... for testing purposes till I find the real problem of course.

GeneralDisorder said:

I have considered this - the turn signal on the passenger front works but the passenger rear does not so switch seems unlikely? The switch definitely could be the problem with the horn and washer motor though. I have pulled up the diagram for the A1 (but not the A1R - don't have) and I'm hoping I can test the output of the column switch to the horn and washer leads to indicate if either are being sent any power.

My biggest issue is definitely the over-volt cut-out though. It definitely occurs with multiple voltage regulators and at the moment seems to occur once after the first drive, and then does not come back. I'm considering wiring in a toggle switch to shut off power to the E terminal (or toggle power to the K11 relay) of the regulator so I can restart the regulator on the fly without shutting down the engine.... for testing purposes till I find the real problem of course.

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sounds like a good idea, but in the end there is only one system that generates power on the truck, and you have swapped half of it… have you measured for AC ripple on the DC outputs?

I haven't checked for AC ripple yet. You really think it could be an SCR/diode failure of the rectifier?

I reviewed the Niehoff troubleshooting documents and I swear when I looked at the LED's on the regulator yesterday after it stopped charging (didn't shut it down and immediately restart as I did today) it was showing a flashing amber, which is:

"Respective system voltage is below regulated setting. Alternator is not producing power or circuit is overloaded. See Chart 1 on page 6 for 28 V systems, Chart 2 on page 7 for 14 V systems."

Not the same failure as the OVCO...... damn now I'm not sure. I'll have to go drive it tomorrow and hope this occurs again so I can stop and check the LED's and note FOR SURE what it's reading. Pretty dang sure it was a flashing amber yesterday. And going back over my notes it was definitely noted as a steady red LED when it went OVCO before I cleaned the LBCD terminals. If that's the case this may be a new fault.

Damn this is a complicated system. What a mess.....

Test drive today - no issues on (less than 1 mile) trip to lunch. Restarted after lunch and alternator did NOT start at all after restart. Checked LED's and both LED's were flashing amber. I pulled and reinstalled the K11 relay with it still running to be sure it was NOT energized (no click when I removed or inserted it). Shut down and restarted - both LED's flashing green. Drove back to shop no problems.

Ok - so in my testing after cleaning LBCD terminals, addressing grounds, etc I went through and tested all three of the voltage regulators I have. They all checked out working so I left the last one I tested which was the original (and most recent build date of 2013) figuring the issue was likely resolved and I have three working regulators.....

But...... remembering back the FIRST failure I had about 100 miles from home - I do recall that the regulator went offline and showed the same two flashing amber lights. At the time I didn't know what they meant and the recommendation (to get home) was to swap in the extra regulator I had (new in box 2012 build date) and after restart everything was good and we rolled home the last 100 miles. The over-voltage-cut-off situation occurred roughly 4 weeks later after dealing with the air compressor that ventilated a piston due to a soaked dryer cartridge with a 2008 date (never changed in the life of the truck) - that's when the solid red LED came up and I have not seen that happen at all (can watch the voltage gauge climb past 30 before it shuts off when that happens) since cleaning and tightening every connection I can find.

So at the moment I'm leaning toward that original (to my purchase) 2013 dated regulator being intermittently bad - possibly because the loose battery terminals and poor connections in conjunction with a 2600 mile trip. So I swapped back to the brand new regulator. I only got in a short test drive but had no problems of any kind. So only time will tell. I'll try for another cold test drive tomorrow and see if this new issue is resolved with the new regulator.

I removed and repeatedly tested the K11 relay in my relay tester - which tests the NC contacts and could not get it to show a fault with the NC contacts (or the NO contacts).

If I recall if the exc power is not present from K11, you get no led’s on the reg…

I have had several successful test drives with the (new old stock) regulator with the 2012 build date the past few days. Got it on the freeway today for a bit and had no issues with the regulator going into flashing amber. So as of this posting I'm calling the 2013 regulator that we drove 2600 miles on with loose battery terminals, corroded LBCD terminals, and an essentially disconnected driver's side headlight ground..... damaged and intermittent. I will keep it as a backup spare or something I can possibly disassemble at some point to learn more about them.

I'm going to build a J1939 interface to the regulator. Because reasons.

Rick

Drove the truck to the DMV today - about 30 miles round trip - and no issues with the charging system.

Of course the Oregon DMV doesn't want to register my truck. Saying they want a "letter from the manufacturer stating the truck meets federal standards for highway use"...... even though the Interstate system was built between the 20's and the 50's specifically (in part) to move troops and equipment..... very insulting that my truck is considered safe for our troops (myself included) but my state is "unsure" about it's safety on our highways..... what a crock. That's OK I have another solution:


Rick

GeneralDisorder said:

Drove the truck to the DMV today - about 30 miles round trip - and no issues with the charging system.

Of course the Oregon DMV doesn't want to register my truck. Saying they want a "letter from the manufacturer stating the truck meets federal standards for highway use"...... even though the Interstate system was built between the 20's and the 50's specifically (in part) to move troops and equipment..... very insulting that my truck is considered safe for our troops (myself included) but my state is "unsure" about it's safety on our highways..... what a crock. That's OK I have another solution:

Register Your Military Vehicle - Dirt Legal

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www.dirtlegal.com

Rick

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There is a lot of documentation that show that meeting the details of the contract is equivalent to the FMVSS. I don’t have it handy but it’s out there.