3rd alternator...why?

[turf]

the larger blue hose is the air inlet for the compressor

[BlackJohn]

Originally Posted by turf

the larger blue hose is the air inlet for the compressor

Ok, for dry air in the compressor. Still can't see that being grid heater.

Can you open it to be sure, no fluids in there I doubt, but what is?


I went looking online at the grid heater and just got results for Ram trucks. That looks similar but for no wires. Maybe they will show if you take that horn apart. Heater should be about 4" square at the bottom of the horn.
or, find the fuse for the grid heating, probably a biggie, pull that and test everything again when engine is warm. There are temp sensors to so maybe they are failing.


John

[cadillackid]

where are those relays located? physically? is that in the electrical panel of the bus body where your switches are or are they in the chassis electrical panel / engine area?


any energized relay will show as a hot spot on an FLIR because the coil generates heat... they will be warm to the touch..



does your trans use the electric modulator? 2 pin canister on the side of the trans or is it cable driven? the modulator is generally wired up so it will only engage in D and heavy throttle.. that device can pull about 20 amps so shouldnt drown out the battery completely.. but is an electrical circuit..



how is your alternator wired? is it wired as a single wire or does it have the 2 pin connector? if it is wired up as an 'SI' or has the sense lead to sense bat voltage,and the excitor lead to turn on the regulator. the way it works is that the excitor lead needs to show voltage or the regulator in the alternator will not turn on.. so if something in the harness is bad and disconnects that excitor lead then it will effectively turn off the alternator and no voltage will be output. you will be driving on the batteries which will run down dead..



if something will truly eating up enough current to be pulling the 130 plus amps that alternator puts out, i'd expect a lot mroe things to be hot.. the big wire coming out of the alternator would be nice and warm at the very least... and the alternator would be hot enough to sizzle water..



however if it is turning off then it would just not output voltage.. I dont have a wiring diagram for your Bus so I cant tell you how the wiring is installed, however.. in a typical installation, the sense lead is a wire going directly to the battery.. (some people just loop it to the alternator output..), and the excitor lead goes to an Ignition fed circuit that is only active when the key is on.. obviously thie works sometimes because the alternator charges at times..



so the test would be if the condition can exist with the bus in drive and someone holding the brake down and parking brake applied at idle.. and you can safely reach your alternator with the engine running, measure voltage from ground to each pin on that little 2 pin connector going into the alternator.. in run both should show a voltage.


just a thought?
-Christopher

[BlackJohn]

Good food for thought Chris, thanks.



For those following, all these tests we been doing are to try and determine if the alternator and regulator are working properly.
I have no diagrams and not sure if front or rear engine so just throwing out all possibilities.


If a decent size alternator like this can't keep up the charging in this case, then proof of it to be working right is a must, before any other checks.


There is a lot could be learned from a 5.9 schematic.


I see he shuts down with a cable controlling fuel supply. I wonder why that happened and by doing that I assume he moves that cable to open the fuel supply.

So, what has happened or changed at the ignition switch to go cable instead of electrically switched fuel supply. There is a lot more here than initially meets the eye.


So far, I think the alt is working fine, the cable from the alt to the battery pos+ seems to deliver to the battery.



There are hot relays which remain unknown. They are a puzzle to be acting that way for sure.


And I don't know what is going on for sure with the starter, if anything.

But for such a big drain, that is my first suspect. Is it getting hot, staying hot as in temp, not energised hot. We know it works but properly?


If anyone has electrical schematics for this 5.9, sure would appreciate a look at them.



Battery age and condition is another distinct possibility even though they seem to be getting the accepatable output of the alterrnator.


John

[cadillackid]

john, the wire im thinking of is not the same as the big POS wire.. it is a small wire that is hot with ignition.. if that wire goes cold the regulator turns off and the alternator wont output..



was this bus always a mechanical shut off or did the original fuel solenoid have issues of shutting the bus down whiule driving so was converted to a mechanical cable?

-Christopher

[turf]

i;ll check the little wire. it was at least in place in its clip into the alt. but i can un snap it, clean it up and put it back easy enough.

i found the relays in BB parts catalog but still did not determine their function. 1 listing calls them "main line relays" and another description says "starter" relays.

i do not see any big grid heater relay or wires top side of the motor.

my battery voltage right now is 12.0v. im going to put the charger on and try and start at lunch like i did yesterday.

we flirred the engine and nothing was overly hot. i especially looked at the alternator and the big cable coming off of it. at 10.4v, it wasnt any hotter than the surrounding engine temps.

today, to me that means the alt wasnt working at 10.4, only the battery?

idk

thanks for all help

[BlackJohn]

Chris, hearing you on the exciter wire clearly.


Not sure if voltage regulator is internal or external to this setup.


At 10.4 vdc something is wrong.



Battery at 12vdc is basically dead.



Turf are your batteries maintenance free or can the cells be checked individually?


John

[BlackJohn]

"i do not see any big grid heater relay or wires top side of the motor."


Don't doubt that, it's in that horn thingy and has to come apart to verify.
Connections in there too and bad temp sensors may call for heat on a warmed up engine, which seems to be what is going on.

Gotta get that grid disconnected and see how charging goes.


John

[Booyah45828]

Dave,

Let me see if I got this correct. At idle in neutral, you have no trouble. The bus charges normally. When put in drive, the voltage drops to 10.4 in a matter of minutes?

If that's all correct, you have a pretty large short. Like 100 amps or larger. That won't register on any fuse or parasitic draw test. You most likely have a battery cable that has had the insulation rubbed through. I'm not sure if you're alternator cable is fused, but that could also be rubbed through as well.
Check them both thoroughly. The reason it gets worse in drive is that under load, the engine will rock over due to worn engine mounts, which when it rocks will create the short.

Think of it like this. Take whatever your alternator amp rating is, add that to the amp hour rating of all your batteries put together, and that is how large of a short you have to have in order to kill the batteries in an hours time. If you do it in half an hour, double that number. We're talking alot of power here, more then any 12 gauge wire will be able to carry. Like hundreds of amps shorted. And the fact that it does it in drive all the more leads to it being starter or alternator cable related.

[BlackJohn]

Exactly Booyah, great explanation on how much power we are talking about shorting out. What's next, a big fire?
This bus has had some strange part changes that point in this direction.
This is the cost of not getting to know your bus folks. Not everything can be jerry-rigged to make it run.


John

[Booyah45828]

What happens next?

Well for starters, the batteries and alternator are hating life right now. Neither component is designed for that much of a load that long. That's the reason he's on his 3rd alternator. He's also deeply discharging the batteries each time which is hard on the electrolyte and terrible for the lead plates. I'd have to guess that the batteries are likely also trashed, they've at least had their life shortened, but test and verify.

As far as fire goes, that all depends on the heat generated, which depends on the size of the cable being shorted. Use this much amperage on a 12 gauge wire and you'll be burning off the insulator for sure. 4 ott battery cable might just start to get warm though.

I wouldn't be so worried about the wires catching fire, but the connections. If the battery connections have corrosion on them, or are loose, you'll generate heat there. To add to that you also have the batteries discharging, which creates hydrogen gas, and you can see how an explosion could happen.

Nothing good is happening with this, so he needs to fix it before any other trips.

[BlackJohn]

Thanks Booyah, great commentary again. Not just this thread but the many comments you have made in other threads, your knowledge is to be respected.



I hope people heed this and pay more attention to how things can go wrong fast.


To me this bus is not roadworthy for any movement with so many undetermined issues.


John

[turf]

a big thank you to all who are following along!

im going to start over here and go back and answer some things maybe i missed communicating.

i have not yet ruled out an over/undertight belt.

the alternator out wire is not glowing hot in the short condition.

i have not covered up the post on the alt yet.

i have not been able to check connections with the starter.

the battery connections are good, i've been chasing this phantom for a while and have been on the batteries.

the shut off solenoid was the first trip to the mechanic. he put the cable on and said he saved me some money. the electric shut off had failed numerous time per the agency i bought the bus from. i bought the bus with a failed solenoid.

i don't think it is related to the trans selector anymore. i did, but not now. the videos posted did not involve the selctor or transmission and the fault happened.

the trans has a mechanical modualtor. i dont recall an electracil cnnection on the trans but that may just be me. it had a speedo wire but not anymore.

any help locating the heater realy or grid appreciated. i don't know where to look.

the hot relays were located in the box outside.

the alternator has 1 big wire and 1 little wire.

the batteries have individual cells.

i no longer think the trans or drive selector are the cause of the short.

right now i'm leaning to worn bearings and the alt/voltage reg failing.

oh, and no burnt/ bare cables

[turf]

hmm, ok

i slipped the belt off and the water pump and alternator both seem solid. no wiggle.

i think the overtight belt option is out now.

im going to start it again and not touch anything and see what happens.

i'll let you know

[BlackJohn]

Originally Posted by turf

do i have a grid heater?

this looks more like a spacer. i see no electrical connection

here are 3 of 4 sides of the spacer/heater. the 4 side is against the cylinder head cover.



and




quickserve lists it as heater/spacer. part #AH9021

On your inline 6, is this about 2 cylinders from the front of the engine?


If you take those 2 bolts out and the 2 we can't see, the grid heater will be in under there I think. In the piece of metal block with the vertical lines. Worth opening now.


You should put up more pics of the general engine layout. Hard to know what is what and where parts sit.


John

[one_eyed_jack]

Turf, I know what your problem is. It's Gremlins! Have had a number of run-ins with the little Buggars myself over the years.
Seriously now, I was up late last night studying all the posts, trying to think of something that has not been covered yet. Do you have a known good battery from another vehicle that you could sub-in for a quick test. Doesn't need to be a big one; my bus starts and runs fine on a single automotive battery. Just one will be fine, tape up the cables not being used, or at least make absolute certain they cant short-out anywhere, hook up the one battery and give her a go. I know, it's a loooong shot but at this point it looks like nearly everything else has been covered. Next thing would be to take that alternator off and get it tested off the vehicle. [Get it away from the Gremlins!]
As far as the heater grid goes, you don't appear to have one, judging by your pics. My bus is a 92, same engine, and it does not have grid heaters either.
Respectfully;
One_Eyed_Jack
P.S. Will take couple pics here in a bit and try to post them.[ One of my bus and one of my 97 Dodge, that does have the intake air heater.]

[BlackJohn]

Originally Posted by turf

a big thank you to all who are following along!

im going to start over here and go back and answer some things maybe i missed communicating.

i have not yet ruled out an over/undertight belt.

the alternator out wire is not glowing hot in the short condition.

i have not covered up the post on the alt yet.

i have not been able to check connections with the starter.

the battery connections are good, i've been chasing this phantom for a while and have been on the batteries.

the shut off solenoid was the first trip to the mechanic. he put the cable on and said he saved me some money. the electric shut off had failed numerous time per the agency i bought the bus from. i bought the bus with a failed solenoid.

i don't think it is related to the trans selector anymore. i did, but not now. the videos posted did not involve the selctor or transmission and the fault happened.

the trans has a mechanical modualtor. i dont recall an electracil cnnection on the trans but that may just be me. it had a speedo wire but not anymore.

any help locating the heater realy or grid appreciated. i don't know where to look.

the hot relays were located in the box outside.

the alternator has 1 big wire and 1 little wire.

the batteries have individual cells.

i no longer think the trans or drive selector are the cause of the short.

right now i'm leaning to worn bearings and the alt/voltage reg failing.

oh, and no burnt/ bare cables

(i) "the alternator out wire is not glowing hot in the short condition."


Never suspected that at all. The starter cable is the one, the big guy form the batteries. That is why the grid must be disconnected or pull the fuse for it. This eliminates the grid form contributing to the faulty condition.
Then you can more think starter issues.


(ii) "i have not covered up the post on the alt yet."


Without taking all these precautions into account at once, you are flogging a dead horse. So simple a task, I don't get it.


(iii) "i have not been able to check connections with the starter."


Same explanation as in (ii), so simple to look and cleanup, check for overheating etc.


(iv) "the battery connections are good, i've been chasing this phantom for a while and have been on the batteries."


Your batteries have had a hard life as Booyah and I agree. They aren't up to snuff if you don't test each cell.
When you boost your bus, you are reading voltage from the boost battery,
not yours.



(v) "the shut off solenoid was the first trip to the mechanic. he put the cable on and said he saved me some money. the electric shut off had failed numerous time per the agency i bought the bus from. i bought the bus with a failed solenoid."


This only saved you money that day the change was made.



Why was it made anyway? There is a reason the solenoid was giving trouble all along and that wasn't established was it?
Going mechanical change here without altering the electrical is likely why we are here.

Was the ign switch wiring reworked to accommodate the change to mechanical solenoid operation? I will bet not.
These electrical engineering designers configure things for a reason.
just pulling wires off a solenoid only complicates life for relays, ECM and who knows what other sensors etc. Those 2 unknown relays are probably related to the troubles also.

When your key goes to start, certain things happen with the whole electrical system. When you rel it to run, other things are supposed to happen and your computer does not know this so compensates as to what it knows. Relays stay on when they should not, others don't come on..dig?


(vi) "oh, and no burnt/ bare cables[/QUOTE]"




This is why larger cables need meggering out. The eye tells you very little about internal condition or resistance.
Resistance is everywhere but some is normal, old cables do fail internally. Take starter cable in for a test or just go new.



(vii) "right now i'm leaning to worn bearings and the alt/voltage



reg failing."


They could be both totally useless but wouldn't put a sudden huge load on the system and be ok a few hours later. Like we said earlier above,

this is huge power loss, not anything else involving the alt's ability to produce current at proper voltage. It's no different than pulling the plug on your bathtub, whoosh, bye bye water.



Need more pics of all these faulty things as to physical location.
Is this bus RE? See, we still don't have the basics to go on.
This would be one expensive mother in a shop to fix, is it worth it?


John



John

[Booyah45828]

A belt isn't going to cause this.

Based off your pics, you don't have a grid heater, so you can rule that out.

The alternator could cause this if it had faulty diodes shorting the positive to ground. Usually they fail open, not shorted, but it's a possibility.

I find it especially hard to fault the alternator considering that you've gone through 3 alternators with the same problem on all three.

I'll say it again, the amount of amperage that is required to flow to kill both of your batteries is a bunch. Enough so that anything with a fuse would blow. So forget about the shifter wires, drive selector, or anything small like that being the problem. You can change those relays if you want but I doubt those are the problem either.

I've seen plates in batteries contact and cause a short, but you'll smell that because it will start to boil off the acid. It's pretty obvious.

You could have a damaged starter solenoid that is shorting internally.

Now that you have a pull handle for engine shut off, your bus will stay running with the key off correct? When the battery voltage is dropping, turn the key off and see how it reacts.

How is the amp and volt readings taken from your gauge in your videos? Do you have a dc amp clamp available to you?

[turf]

no dc amp clamp. just the reading off the meter in the video for amps.

i got underneath and checked ground straps, starter wire connections, i jiggled the little wire on the alternator and moved the big wire a bit. it ran snug against the oil filter so now its an inch off.

then i started it up. ran for an hour. no problems. i shut it off.
Booyah, when i shut off the key today. the battery meter went from a charging condition to 0.
an hour later the bus started on its own. unassisted by charger.
another hour later and i just tried again. no problem starting. charging is fine. no fault showing.

just for orientation. this is a front engine flat front TC2000
here is engine picture, the alternator is adjacent to my cat box.

[turf]

i got snow today!

i started the buus on its own. no charging, just the engine block heater plugged in and she started and charge fine.
i ran it for about 4 hours, drove 5 miles to the rv dump and the meter said 14.1 all the way charging at .7A

after returning from the trip and shutting the bus down. the meter shows the batteries at 12.9v and the battery at 89% charge.

this was probably the last test i got before the tuesday and the skoolipalooza trip.

thanks for all the help! i am still baffled why the fault comes and goes. i was ready to buy batteries until the bus started fine this morning. maybe i should find an alternatoer to pack with me?

anyways, thanks for all the help!!!! hopefully im not on the side of the road next time i post.

Dave