Think its a similar problem for both of us!!
I would like to thank everyone for there great inputs and help!
m7 Attitude box problems
- Thread starter whitdmilkman
- Start date
Think its a similar problem for both of us!!
I would like to thank everyone for there great inputs and help!
P
product tester
Well-known member
fuel controller ground goes to chassi only not to rectifire as both sides of the ac have + charge if you hooked your attitude box there you might havwe fried it.
I think your mistaken, but I'm all ears. I always like to learn more.
Both sides of the AC have + charge?........ with reference to what?
J
JROD
Well-known member
Both sides going IN to the rectifier have a + charge but after 'rectifying' it comes OUT as a DC+ and a DC- so theoretically if you're pulling DC+ out you would also have to hook your ground back to the DC- coming out of the rectifier just like you have to do with the fuel pump. I should've known this.
Sorry guys, but that is plain wrong.
AC is alternating current That mean one AC lead is + and the other is - for a brief part of a second. The next instant the lead that was + then goes - and the other lead that was - then goes + . The AC in your house does this 60 times per second. In a sled it does it more often.
If both leads were positive then you could have no current flow. Electrons flow from one polarity to the other. It will not flow between two of the same polarities at the exact same time.
When you put a bridge rectifier in an AC circuit you are using 4 diodes connected in a way that allows the polarity to flop back and forth on the input but come out + and - on the output.
I said in an earlier post that you can't hook the - of the bridge rectifier up to chassis ground if the AC is also grounded on one side. Let me clarifiy a bit more:
Well of course you can, but you will effectively short 1/2 of the AC and put a huge load on the stator and eventually burn up the bridge. The other 1/2 of the AC power will still continue to do some work at close to normal voltage. It still looks like you have power.
What is happening: the stator goes from dead short to moderate load to dead short to moderate load 60 - 120 times per second. This would make that particular system act weak and burn up and get a bad rep for having a poor stator..............sound familiar?......M7 stators.....LOL
If you look at Ms with CCUs you will find that the AC is not grounded only the DC...............hmmmmmmm wonder why???
I truely hope this helps understand what is going on with some of these systems.
tony you rock man, super helpful writeup.
and its funny, this is especially fresh considering we just had this conversation a few days ago. It sort of made sense at first.. then I drew the circuit up, THEN, I started thinking about AC waves and thinking how things are flowing throught the bridge, it is VERY obvious what the problem is then. its like staring at a garden hose with a giant gash and understanding that DUH< theres a little "leakage" persay of current.
and it does seem weird coming from wiring 12v automotive dc stuff to not be chassis grounding on the system, but again, if you look at it, it ALL works out. like you said, the power is there, you just have to use it, not dump it into the chassis.
and its funny, this is especially fresh considering we just had this conversation a few days ago. It sort of made sense at first.. then I drew the circuit up, THEN, I started thinking about AC waves and thinking how things are flowing throught the bridge, it is VERY obvious what the problem is then. its like staring at a garden hose with a giant gash and understanding that DUH< theres a little "leakage" persay of current.
and it does seem weird coming from wiring 12v automotive dc stuff to not be chassis grounding on the system, but again, if you look at it, it ALL works out. like you said, the power is there, you just have to use it, not dump it into the chassis.
J
JROD
Well-known member
You are right... My wording was wrong but I know what product tester is saying. I'm no electrician but I understand how the AC current works. I didn't mean they are both + charged but that they are both "hot" so to speak. An AC ground is not like a DC ground.
A bridge rectifier splits the sine waves of AC and as you said splits them into a + and a - DC current. So if someone was to ground a DC ground to an AC - then yes, without a doubt you are creating a short between 2 different electrical systems so long as power is flowing through both systems.
What I was saying was my ground coming out of my fuel controller is on a chassis ground as we speak. I have my DC + pulled off of my rectifier so therefore I'm not completing any circuit whatsoever so therefore not a short, I hope.... D@mn, now you got me thinking..... Either way, my auxiliary injector circuit is not being completed and I need to connect them to a DC ground and a DC power, NOT A CHASSIS GROUND. A chassis ground would only work on a sled or vehicle using a complete DC current. Is that better or am I still mistaken?
A bridge rectifier splits the sine waves of AC and as you said splits them into a + and a - DC current. So if someone was to ground a DC ground to an AC - then yes, without a doubt you are creating a short between 2 different electrical systems so long as power is flowing through both systems.
What I was saying was my ground coming out of my fuel controller is on a chassis ground as we speak. I have my DC + pulled off of my rectifier so therefore I'm not completing any circuit whatsoever so therefore not a short, I hope.... D@mn, now you got me thinking..... Either way, my auxiliary injector circuit is not being completed and I need to connect them to a DC ground and a DC power, NOT A CHASSIS GROUND. A chassis ground would only work on a sled or vehicle using a complete DC current. Is that better or am I still mistaken?
!!!!YOU READY!!!!
!!!!YOU READY!!!!
!!!!!CUT THE RED WIRE!!!!!
!!!!!SATURDAY IS COMING FAST BRO!!!!!
!!!!!!!NO CUT THE BLACK WIRE!!!!!!
!!!!!LMR!!!!!
!!!!YOU READY!!!!
!!!!!CUT THE RED WIRE!!!!!
!!!!!SATURDAY IS COMING FAST BRO!!!!!
!!!!!!!NO CUT THE BLACK WIRE!!!!!!
!!!!!LMR!!!!!
You're right in an AC circuit they are both hot, but an AC ground is a ground non the less. It is a connection point...no different than a common terminal on a terminal strip. A DC ground is just a connection point too.
Right on! One exception: Power doesn't have to flow to any DC device but the bridge will conducting through the ungrounded AC terminal through the diode that connects to the negative terminal just like it was a direct wire during 1/2 of the wave form.
Like I mentioned above in my first post. This grounded bridge thing may not be the whole problem, but It raise a red flag for me. I will assure that scenario has to cause long term problems.
The devices that are pulling power off of the (grounded)rectifier are not the problem. It's already dumping 1/2 the wave form(and stator power) all by it's self. You no longer have the benefit of full wave rectifier. You could put a single diode in the circuit and get the same 1/2 wave DC signal without the huge load on the stator.
One other thing to think about. I have my CCU. It's really only a glorified bridge rectifier with a few other goodies in it. It is obviously grounded to the chassis(AC leads are not). I do not ground anything that needs DC to run..... including my PL box. I hooked the power wires to positive and negative. Same for my fuel pump and o2 gauge. I hate to rely on ground connections for anything but static and spark plugs.
This has been a cool thread. I know there are lots of misconceptions with electrical and this topic hopefully will shed some light on one.
This m7 @ 8 lbs pulls harder than my m8 turbo @ 12 lbs! AMAZING!!!!!
But 2nd half of day my box keeps reseting and sled would fall on its face.
everytime in the past with other sleds this is usually something grounding out or a short. Cant find any wires rubbed through. I cant find anything! something else thats wierd is it only resets the box when i come on boost..... I rode out on the trail and it never did it again unless i hit boost....???
Any ideas??????
But 2nd half of day my box keeps reseting and sled would fall on its face.
everytime in the past with other sleds this is usually something grounding out or a short. Cant find any wires rubbed through. I cant find anything! something else thats wierd is it only resets the box when i come on boost..... I rode out on the trail and it never did it again unless i hit boost....???
Any ideas??????
I'm curious, does your box turn on the secondary injectors at 8 lbs of boost?
When you were on the trail, weren't you building at least a few lbs of boost, and that didn't bother it?
I guess where I'm going with this, is do you think that the problem comes about when the boost is high enough to turn on the secondaries?
I'm with JROD, does it reset to 0 or some other values
J
JROD
Well-known member
Under most fuel maps with the Dobeck controllers, the auxiliary injectors start coming on at low boost, right around 2 psi and then work in tandem with the primary injectors as it comes up in psi.
I've noticed that the Boondocker boxes normally bring in the auxiliaries at a point much higher, after the primaries near max duty cycle.
However, the Dobeck boxes are capable of being infinitely adjustable but the fuel map would've had to be custom programmed by someone with the proper equipment, So it's possible to have the auxiliaries come on late in the boost curve but not probable.
Without more info about just exactly what it's doing, it sounds like a short on the auxiliary side of the circuit or a bad connection in the main injector harness, whether it be on the fuel controller side or the factory harness. Could be either.
***FYI- moved my auxiliary injector DC power to my factory fuel pump wires and auxiliaries finally worked flawlessly.
it doesnt reset my settings it cycles like i just started the sled.....
i also put my secondary power to my fuel pump and it worked great for half the day.... I think the attitude box brings on the secondarys around 5 lbs
i also put my secondary power to my fuel pump and it worked great for half the day.... I think the attitude box brings on the secondarys around 5 lbs
The sed falls on its face! Well I almost land on my face from almost coming over the handle bars. The green light cycles like when u start em....
I think i found it!!!!!!!!!!!!!!!!!!!!
brown wire for the dc was not grounded to chassie it was just touching it and not bolted to chassie!!!
brown wire for the dc was not grounded to chassie it was just touching it and not bolted to chassie!!!
