Thought 145amp alternator enough for additional accessories. Guess not?

[Spaceman Spiff]

"Holy crow...why is this test so elusive? Am I mistaken...I thought you just needed one of those high amp multimeters??? Is there something I'm missing? We would do it but only have one that goes up to 20amp and didn't want to pay for one just for this test."
 . . .
another point abusing your charging system with this test could fry stuff if the tech is not careful.

You need an adjustable load that goes at least as high as you want to test.  I used an adjustable carbon pile and an analog ammeter when I was testing alternators (back in the '70's).  I would assume that there are automated machines that do that now, although probably only at alternator manufacturers. Not much call for the test - just do a voltage test and replace if alternator doesn't meet spec.

You have to know what you are doing as the alternator can get real hot if you put too much load on it.

My cheap Mastertech clamp on ammeter has a 400A setting.  Never tried it.

 

[Gary68]

not reading all the replies but you can have 1000 amp alt but if the wire can only handle 20 amps thats all you will get,most stock alt wires are 10-12 gauge or a 30 amp wire,sternwake made me go 2/0 wire or be forever mocked,i've seen 90 amps going in to the house battery out of my 150 amp alt

he still mocks me though,just for the fun of it

 

[highdesertranger]

yeah the art of thinking through what needs to be done and following troubleshooting guides has given way to hook it up to the xyz machine and do what it says. critical thinking is a rarity now a days.

I should have added the the builders and rebuilders have a machine that does it. I know I have seen the little paper that comes with a new alternator and has the performance graph. LOL

highdesertranger

 

[PineyCruisin]

HDR: Maybe I am misunderstanding... I assumed typical garages have something that can easily be used to simulate a load and then all that is needed is an ammeter or shunt/multimeter at the cable coming from the alternator to battery. My alternator is rated at 145 amps so would assume they can load it to not go that high. I also thought measuring the load of my system is even easier.....simply turn on everything and read the measurement on whatever amp meter they have again. 

Could be I am assuming too much about all this.

 

[PineyCruisin]

Spiff: I should hit you with a wet noodle for telling me to go on a wild goose chase, if you are saying only alternator shops do this test. lol. I'm utterly astonished with all the electronic stuff that are constantly being added to vehicles (not just accessories either) that more people don't need to know if their alternators are really putting out the amps to handle their loads. 

I'm curious about the carbon pile you spoke of.....what is that exactly?

 

[PineyCruisin]

,sternwake made me go 2/0 wire or be forever mocked,i've seen 90 amps going in to the house battery out of my 150 amp alt

he still mocks me though,just for the fun of it

We got the same gauge cable when we added the kill switch as stock cable coming out of alternator, which is 4awg, and fortunately got absolutely no voltage drop around it. Wonder why sternwake told you to get 2?

 

[bullfrog]

Never question the master! Lol!!! 4 gauge is good for maximum 70 amps. A variable carbon pile resistor is an adjustable load producing device with lots of cooling to handle the heat produced by the resistance to large amounts of current flow usually for automotive use at least 400 amps to 1000 amps.

 

[PineyCruisin]

People need to learn how and why things work. Then learn how to problem solve. Most are trained to push a button, look at a result, compare it to the chart and replace either a battery or an alternator. I sure am turning into a grumpy old man! Sorry for the rant. Wonder how many even know how to install an amp meter that doesn’t clip on?

It seems that is exactly what is happening. They are merely customer service agents and not true mechanics, in my mind. What I don't understand is when I stressed over and over that I wanted to know the amps, every single one of them (manager of the Pepboys service dept including) thought voltage was equivalent. That I don't understand at all.

 

[PineyCruisin]

Never question the master! Lol!!! 4 gauge is good for maximum 70 amps. A variable carbon pile resistor is an adjustable load producing device with lots of cooling to handle the heat produced by the resistance to large amounts of current flow usually for automotive use at least 400 amps to 1000 amps.

 Hmmm. Did we mistakenly check the size of the stock cable that is meant to go with the smaller stock alternator? (don't remember the amps of that one without googling) Come to think of it....I specifically called BlueSea to make sure we got the right size and they recommended 4awg even with our size alternator. If this tech was like the techs I talked to today, I am going to scream!

I didn't even think to doublecheck the amp rating for that gauge wire. Should I be worried?

 

[bullfrog]

When I worked on cars and trucks in 1960 to 1980 each year I would need to read some where between 500 to 1500 pages of information on each new model vehicle each manufacturer put out. The manufacturers had several factory schools that I would attend usually lasting from a day to ten days several times a year and that was after attending Vocational Schools for 6 hours a day for 2 years just learning basics and over 8 months in electronics schools in the military. There are lots of us out there that lived to build hot rods and cars from the ground up. As cars became more complicated and manufacturers more secretive with their technology in order to make higher profits it became difficult to be an independent mechanic for a living. When the government created laws that somewhat required the manufacturers to standardize emissions that helped but then mechanics had to become computer technicians as well. Today’s master mechanics do most of their troubleshooting and tuning with a lap top using highly specialized programs furnished and created by manufacturers or aftermarket tech companies. Things became so specialized that it was near impossible for one person to learn it all and continue to keep up with new developing technologies. So manufacturers developed computers/machines that could connect to the car, collect information, and determine the problem and suggest what part needed to be replaced to fix the problem. Teaching someone how to use the computer was easier and less time consuming than explaining how and why things work. So today in many garages this is what you find. Many mechanics spend a few years in a dealer ship then go independent only to have technology make their knowledge obsolete in 10 or 15 years. Most retire after 20 or 30 years as your body is not as flexible and joints don’t work so well after years of crawling in and under vehicles. The new young guys in parts stores and garages are either just learning or trying to develop skills to make money and drive today’s fast cars mainly, learning how things work just takes too long for most of them and doesn’t pay enough to bother. That fact was made clear to me the other day when I found a few highly recommended garages that wouldn’t work on anything older than 2002 model vehicles. They just don’t know how to without a computer to tell them what is wrong. We all should be worried! Lol!!!

 

[Gary68]

ok,scanned the thread

your alt should be pumping mid 14 volts period,if not something is wrong with it,the volts will stay the same,the amps will lower as the battery fills

you are running everything off starter battery? through stock wires,ciggy plug? if so not good,the factory wiring is the minimum they can get away with,ciggy plugs should be killed on sight,best to have a house battery

alt,4 gauge wire is ok,a switch,i use a constant duty solenoid with a toggle on the activation wire,stern uses a on/off manual switch,ok 4 gauge wire to appropriate fuse on house battery,battery to master on/off switch then to fuse box and hook your gizmos to the fuse box

stern told me to wire my fridge directly to house battery with inline fuse

i kill ciggy plugs and replace them with anderson powerpoles
solar is a must

 

[PineyCruisin]

Found this chart that shows recommended battery wire size

https://alternatorparts.com/wire-size-chart.html

It looks like we are just OK with 4awg since we need only a 9 inch cable to go from battery to disconnect switch. But, hubs went to the BlueSea website and looked up the installation guide for our model and BlueSea specifically calls for 4/0 awg so the wrong cable was purchased. :dodgy: I am sure I am the one who made the mistake, and not the BlueSea tech because I have no idea what the difference between 4awg and 4/0 awg is.

Good lordie...there is never an end to learning about electric! Too tired to research tonight. But, we do know we are going to order a different cable....either the 4/0 that is recommended or better. Any advice appreciated.

 

[bullfrog]

4awg wire is about a 1/4” in diameter, a 4/0 or 0000 wire is about 1/2” in diameter and costs much more and more difficult to route or make bend around things. It wouldn’t need to be 4/0 for such a short, 9” distance, however if you are going 10 or 15 feet then at least 2/0,just check the charts for the type of wire and the total distance it needs to run. If you want to go bigger the is no harm but you will pay more money.

 

[Gary68]

sternwake write up on alternator charging https://vandwellerforum.com/thread-654.html

my ordeal with it https://vandwellerforum.com/thread-1070.html

 

[PineyCruisin]

Bullfrog, I loved reading about the development thru the ages of the mechanic. I have a great respect for a good one. What you say makes perfect sense. I mean, take my problem for instance...I certainly wouldn't expect any tech to remember the nuances of this complicated-as-all-get-out charge system that was only around for 3 years, 12 years ago to have been able to troubleshoot my problem. I only thank my lucky stars that you posted about older models having external regulators, and serendipitously googled just the right terminology so that the GM service bulletin popped up near the top. If these stars didn't line up perfectly, I'd still be racking my brain about it. 

And I have to laugh at the irony at the end of your story....you and HDR want to steer clear of the newer vehicles to simplify troubleshooting and the younger ones want to stay away from the older cars to simplify troubleshooting. lol

 

[bullfrog]

Sternwake is by far the best electrical specialist for this stuff I have read. I highly recommend reading his thread. It will be more than anyone needs to know! Lol!!! Your system is an odd one for sure!

 

[PineyCruisin]

Thanks, Gary. I am definitely going to take the time to read through that thread.

Edited to add: tomorrow. Err...rather, being that I'm in EST, later today.

 

[nature lover]

Piney Cruising - I’ve been reading this thread regularly with nothing to add because I’m just learning a little bit about electricity myself. But my ears perked up when you said EST. So whereabouts are you? I once had a dream of getting all the east coasters together then this thing called Covid came about and plans changed. I am still dreaming about the future maybe we can have a mini Eastern “RTR“ Someday. If I’ve already asked you where you’re from forgive me I was never good at remembering and it is much worse today. Thank God he doesn’t forget. God bless the nomads especially those in eastern standard time.

 

[PineyCruisin]

Nature Lover: sorry, it took so long to reply. I'm in NJ...Jersey shore.

 

[PineyCruisin]

Had to forego trying to solve the crazy alternator problems due to some health issues that hubs has been battling but we are back at it again.

Here's the latest update:

1 - Tested the possibility of system entering "fuel ecomony mode" and forcing alternator to drop to a lower voltage and seeing if, by turning on the headlights, could force back to standard mode and raise the voltage back up. So, went on the parkway, plugged in all the accessories that had been used during the very first test (ie,  the 6.7 amp Jackery charger, 3 amp Indel fridge, .5 amp GPS, .5 amp dashcam) and turned on the headlights, that was recommended in the service bulletin to get the RVC system out of fuel economy mode, and drove between 60-65 mph for 35-40 minutes. The voltage while driving never dropped below 13.8. RESULTS: Battery voltage dropped from 12.6 to ~12.24. This was even worse drop than the first test...totally disappointing. The battery again was able to charge up fully and quickly when not plugging anything in. (never, ever have had a problem getting the battery fully charged when nothing plugged in which has made this all more confusing)

2 - It then occurred to me that the total amps I was using at the ciggie ports (~11 amps....remember, I had nothing else in the van turned on when testing, just the stuff plugged into the ciggie ports) was lower than if I had just the A/C and headlights on (~30 amps)  so obviously the question of whether the alternator should have been able to handle those 11 amps was "YES, OF COURSE, IT SHOULD HAVE". Duh. So now the worry was whether it was able to handle *any* load whatsoever. So, while on a trip, turned on the A/C to high, headlights, and radio when driving at a steady 55 mph without any stop lights for ~30 minutes. Voltage while driving stayed around 13.9 again. RESULTS: the battery voltage dropped from 12.6 to 12.37!

3 - Found a friend with a clamp meter and a Blue Driver Pro OBD II so was able to finally get some sort of amp output measurement on the alternator. With no van accessories turned on, in idle: 19 amps. With all accessories on (hi beams, heater blower on highest fan setting, 4 way blinkers, radio): 52 amps. With all accessories turned on, Jackery charger and Indel plugged in: 62 amps. These numbers seemed to be exactly what was needed and this was in idle! (in retrospect I'm sorry I didn't get a reading at higher rpms to see if something strange happened) Also, the obd ii showed no codes and he was able to connect to the ECU (or whatever module controlled the alternator regulator) and it seemed to be responding as expected.

I was speaking with one mechanic at a local repair shop about the problem (yet another mechanic who assured me they had a clamp meter to measure amps but when I showed up, only had a little multimeter to measure voltage...errr) who said that their shop does not deal with any aftermarket alternators anymore because of all the problems they cause. From this, maybe this aftermarket alternator is just not communicating well with the van's complicated regulating system?

The next step is now to replace the aftermarket with a new AC Delco original alternator. Hopefully that solves everything. <fingers crossed>

I'm just glad that we were so obsessed with checking battery voltage because we may have very well have killed this battery while driving.