Rerouting alternator main cable
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Cargo Master
Joined: Oct 2003
Posts: 2,833
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From: Jefferson, Iowa
Rerouting alternator main cable
I was reading Ed's website ficmrepair.com, and it says one thing that would help with getting battery voltages up quicker is to take a wire straight from the main post on the alternator and connect it to the batteries. In his information he says the alternator does not charge until the glow plugs are off. So there must be a relay somewhere to disconnect the alternator from the batteries while the glow plugs are on. Where is this or how does it work?
Former Vendor
Joined: Feb 2010
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There is no relay, just an undersized alternator. While the alternator DOES charge as soon as it spins up, it does not have the capability to provide enough current to offset the draw from the glow plugs. Tack on the propensity for folks to run their blower motors/heated seats/radios, etc right away and the result is a stressed out FICM. Of course, the issue is exacerbated further by shorter trips and other regular use cases.
I run DC Power's 270XP alternator on my truck and have seen HUGE gains in the after-start voltage number department as a result. Let me know if I can hook you up with one of these bad boys for a few nickels off of what you can get them for on the DC Power site (though, really, the 185amp OEM unit is a huge upgrade all by its lonesome for half the money, even if it, too, doesn't quite cover this draw). The choice of which one is best is largely dependent on the duration of trips, the frequency of the shorter trips, and of course what other goodies (snow plows, inverters, and the like) you may be running.
Hotshot
Joined: Apr 2010
Posts: 19,072
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From: Saratoga Springs,UT
Here is a Pic of what DC Power sent me with my Alternator and this is How they told me to Run it
The grey part of the wire is a Fusable Link
here is More
Ford Truck Enthusiasts Forums - BLADE35's Album: DC Power Alternator & Wire Upgrade
The grey part of the wire is a Fusable Link
here is More
Ford Truck Enthusiasts Forums - BLADE35's Album: DC Power Alternator & Wire Upgrade
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Josh
Fleet Owner
Joined: Nov 2003
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I simply told him of this thread and the ridiculous responses it might (er will probably) get. No one was "taking credit" for anything as you put it, that was Ed being gracious.
Oddly enough, the post (#3) below is from a person (who claims to be a Professional Engineer - not sure what discipline though) on a thread over on TDS.
http://www.thedieselstop.com/forums/...nators-402361/
"In modern vehicles -- all of them, not just the ones with Diesel engines or dual alternators -- the alternator(s) is turned off while cranking to reduce the load on the starter motor and battery current.
The alternator remains off until a stable idle is achieved, then is gradually and smoothly ramped up from zero to full output, avoiding the sag & bump in idle speed that would occur if you just suddenly switched the alternator on. But this doesn't take a minute or two; it takes maybe 10-20 seconds."
I am not posting the above for any reason other than curiosity of how/why he could make the statement that the unit would "remain off until a stable idle is achieved", and to also comment on his belief that apparently there are controls in the alternator for a gradual ramp up (like a motor soft-start perhaps?). A few "technical" comments on his post might be informative.
Oddly enough, the post (#3) below is from a person (who claims to be a Professional Engineer - not sure what discipline though) on a thread over on TDS.
http://www.thedieselstop.com/forums/...nators-402361/
"In modern vehicles -- all of them, not just the ones with Diesel engines or dual alternators -- the alternator(s) is turned off while cranking to reduce the load on the starter motor and battery current.
The alternator remains off until a stable idle is achieved, then is gradually and smoothly ramped up from zero to full output, avoiding the sag & bump in idle speed that would occur if you just suddenly switched the alternator on. But this doesn't take a minute or two; it takes maybe 10-20 seconds."
I am not posting the above for any reason other than curiosity of how/why he could make the statement that the unit would "remain off until a stable idle is achieved", and to also comment on his belief that apparently there are controls in the alternator for a gradual ramp up (like a motor soft-start perhaps?). A few "technical" comments on his post might be informative.
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Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 60
I simply told him of this thread and the ridiculous responses it might (er will probably) get. No one was "taking credit" for anything as you put it, that was Ed being gracious.
Oddly enough, the post (#3) below is from a person (who claims to be a Professional Engineer - not sure what discipline though) on a thread over on TDS.
Two Alternators ?? - Diesel Forum - TheDieselStop.com
"In modern vehicles -- all of them, not just the ones with Diesel engines or dual alternators -- the alternator(s) is turned off while cranking to reduce the load on the starter motor and battery current.
The alternator remains off until a stable idle is achieved, then is gradually and smoothly ramped up from zero to full output, avoiding the sag & bump in idle speed that would occur if you just suddenly switched the alternator on. But this doesn't take a minute or two; it takes maybe 10-20 seconds."
I am not posting the above for any reason other than curiosity of how/why he could make the statement that the unit would "remain off until a stable idle is achieved", and to also comment on his belief that apparently there are controls in the alternator for a gradual ramp up (like a motor soft-start perhaps?). A few "technical" comments on his post might be informative.
Oddly enough, the post (#3) below is from a person (who claims to be a Professional Engineer - not sure what discipline though) on a thread over on TDS.
Two Alternators ?? - Diesel Forum - TheDieselStop.com
"In modern vehicles -- all of them, not just the ones with Diesel engines or dual alternators -- the alternator(s) is turned off while cranking to reduce the load on the starter motor and battery current.
The alternator remains off until a stable idle is achieved, then is gradually and smoothly ramped up from zero to full output, avoiding the sag & bump in idle speed that would occur if you just suddenly switched the alternator on. But this doesn't take a minute or two; it takes maybe 10-20 seconds."
I am not posting the above for any reason other than curiosity of how/why he could make the statement that the unit would "remain off until a stable idle is achieved", and to also comment on his belief that apparently there are controls in the alternator for a gradual ramp up (like a motor soft-start perhaps?). A few "technical" comments on his post might be informative.
Josh
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Brett Foote
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I agreed with you since somebody claimed there was a alternator delay when starting
We know the stock alternator output can't handle the glowplugs and voltage drops because of alternator saturation
Both mark and you have been very generous with your help/posts on this forum
We know the stock alternator output can't handle the glowplugs and voltage drops because of alternator saturation Both mark and you have been very generous with your help/posts on this forum
Fleet Owner
Joined: Apr 2012
Posts: 27,307
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From: Spanaway
But I got the same results as you did. What I was watching with mine was amps on the B+
or alternator output cable and also voltage. Just as soon as it is turning it is making power.
Would be of interest to see how the dual alternator acts.
After the "My alternator is taking a crap" Thread I also upgraded mine to the HD 140 AMP
top dual unit with a smaller pulley. I now see a much faster rate of recovery after starting.
Sean
Former Vendor
Joined: Feb 2010
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Here's how I routed my DC Power cable kit. Note that orders made through us provide the longer length wiring necessary to allow this path without any extra increase in cost. You really want to avoid the heat from the CAC tube.
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