FLP question
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Tuned
Joined: Mar 2007
Posts: 342
Likes: 1
From: South central kansas
FLP question
I am thinking that it may be time for new batteries. On ScanGuage II I have noticed when I start truck (before turning the key past acc) that my FLP is 10.5 to 11.0. FICM voltage is around 46 (never lower) and battery voltage is 11.4 to 11.7. After truck is started everything begins to rise and then runs at the correct #'s (FLP - 11.5, FMP - 47.5-48.5, and voltage 13.5-13.9). Just curious if those #'s alone can justify new batteries. Mine are around 3 years old now, so I am expecting it any time. I didnt drive truck all weekend and noticed slow start yesterday evening, which is what got me to looking.
Lead Driver
Joined: Dec 2006
Posts: 6,496
Likes: 94
From: So. Jersey
It never hurts to have the batteries load tested. I just had mine covered under warranty because the 2 year old Autozones would crank slow after a night or two sitting.
But with what you're saying I'd replace the FICM relay. Once the glow plugs stop cycling and the alternator kicks in, you should have 13-14 volt at FL, FV, & BATT. Having 11v shows a problem on the FL side.
But with what you're saying I'd replace the FICM relay. Once the glow plugs stop cycling and the alternator kicks in, you should have 13-14 volt at FL, FV, & BATT. Having 11v shows a problem on the FL side.
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Tuned
Joined: Mar 2007
Posts: 342
Likes: 1
From: South central kansas
I was wrong with my figures. Never trust your memory. LOL. I did a KOEO test this morning before startup. FLP=10.5v, FMP=dropped to 43.5 when glow plug light shut off, started at 46v, main voltage 11.0. FLP and main voltage stayed the same from KOEO until truck ran for 45 seconds or so, then they both started climbing. Once truck was warmed up FLP ran 13.0 to 14.0 and voltage ran at 13.7 to 13.9. The FMP dropped from 46 to 43.5 with KOEO, as soon as engine started went back to 46 then climbed to 47.5 to 48.5 after warmed up. I remember hearing FICM should never be under 45, and as soon as the engine turned over(before it was even running)the FMP recovered to 46 then jumped to normal voltage while running. I guess I can go get batteries load tested. Thanks for the help.
Postmaster
Joined: Jan 2005
Posts: 4,424
Likes: 12
From: BC Canada
Charge both batteries individually and then check each cell with hydrometer. This will help you identify a weak cell. Then load test each battery separately as well. How clean are your terminals, and ground straps at the frame rails both sides. Probably worth a look at thes things before new batteries, but that does seem low.
Lead Driver
Joined: Jul 2004
Posts: 6,950
Likes: 510
From: Foothills, CA
Two other things: what is your alternator set-up? Also take a look at Jack's (TooManyToys.) thread: "Improving Battery Cables for Battery Life" -- it is a real eye opener... And on the alternator: I have the Factory 140A and did the swap out to the smaller pulley (58mm), one of the biggest differences I see is on cold start and anytime the engine is at low RPMs...
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Tuned
Joined: Mar 2007
Posts: 342
Likes: 1
From: South central kansas
I replaced alternator last fall due to light coming on on dash panel (doesn't mean it is good, but still) with the heavier motorcraft unit I think a 155 amp. Even after changing alternator light still came on. Ended up having a pinched wire where pass fenderwell meets fender. Pulled and taped wire, problem went away, probably didn't need to change alternator, but left it on anyway. It is stock pulley. I did read the article on the battery cables and will be doing that upgrade soon.
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Former Vendor
Joined: Feb 2010
Posts: 1,803
Likes: 4
If following the correction of the battery/wiring/alternator issues the FICM continues to dip below 45, I'd classify it as damaged. If that is the case, send it on over and we'll take a peek at it for you.
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Lead Driver
Joined: Oct 2010
Posts: 5,420
Likes: 16
From: Ouray, CO
For what it's worth, I've bought the full Wire Upgrade kit along with a DC XP270 alternator from Ed @ Ficmrepair. I have a digital volt gauge which is wired in to my under-dash fuss panel to monitor voltage.
We drove 1000 miles over the weekend and my gauge showed 14.3-14.5 the entire time. Immediately after starting, my voltage sits at 11.8 - 12.5 while the glow-plugs are on, then it goes to 14.4-14.6 and gradually drops a few tenths once I've driven a few minutes.
The stock alternator in combination with "just" the stock battery cables just doesn't seem like the best choice.
We have lots of rain in FL, on the stock setup, at night, with wipers, rear-defroster on, A/C on, headlights on pulling up to a stop light, the gauge's voltage alarm would go off reading 12.2-12.5. I'd shutoff the rear-defroster and sometimes the wipers to get the alarm to shut off.
NO voltage issues since the upgrade, still using the same batteries in my signature as before. It's been a great upgrade, PLUS Ed is great to deal with.
We drove 1000 miles over the weekend and my gauge showed 14.3-14.5 the entire time. Immediately after starting, my voltage sits at 11.8 - 12.5 while the glow-plugs are on, then it goes to 14.4-14.6 and gradually drops a few tenths once I've driven a few minutes.
The stock alternator in combination with "just" the stock battery cables just doesn't seem like the best choice.
We have lots of rain in FL, on the stock setup, at night, with wipers, rear-defroster on, A/C on, headlights on pulling up to a stop light, the gauge's voltage alarm would go off reading 12.2-12.5. I'd shutoff the rear-defroster and sometimes the wipers to get the alarm to shut off.
NO voltage issues since the upgrade, still using the same batteries in my signature as before. It's been a great upgrade, PLUS Ed is great to deal with.
Former Vendor
Joined: Feb 2010
Posts: 1,803
Likes: 4
For what it's worth, I've bought the full Wire Upgrade kit along with a DC XP270 alternator from Ed @ Ficmrepair. I have a digital volt gauge which is wired in to my under-dash fuss panel to monitor voltage.
We drove 1000 miles over the weekend and my gauge showed 14.3-14.5 the entire time. Immediately after starting, my voltage sits at 12.4 - 12.6 while the glow-plugs are on, then it goes to 14.4-14.6 and gradually drops a few tenths once I've driven a few minutes.
The stock alternator in combination with "just" the stock battery cables just doesn't seem like the best choice.
We have lots of rain in FL, on the stock setup, at night, with wipers, rear-defroster on, A/C on, headlights on pulling up to a stop light, the gauge's voltage alarm would go off reading 12.2-12.5. I'd shutoff the rear-defroster and sometimes the wipers to get the alarm to shut off.
NO voltage issues since the upgrade, still using the same batteries in my signature as before. It's been a great upgrade, PLUS Ed is great to deal with.
We drove 1000 miles over the weekend and my gauge showed 14.3-14.5 the entire time. Immediately after starting, my voltage sits at 12.4 - 12.6 while the glow-plugs are on, then it goes to 14.4-14.6 and gradually drops a few tenths once I've driven a few minutes.
The stock alternator in combination with "just" the stock battery cables just doesn't seem like the best choice.
We have lots of rain in FL, on the stock setup, at night, with wipers, rear-defroster on, A/C on, headlights on pulling up to a stop light, the gauge's voltage alarm would go off reading 12.2-12.5. I'd shutoff the rear-defroster and sometimes the wipers to get the alarm to shut off.
NO voltage issues since the upgrade, still using the same batteries in my signature as before. It's been a great upgrade, PLUS Ed is great to deal with.
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