Vehicle Electrical Charging System.

Application is 2001 F250 w/Powerstroke and automatic. My question; is it normal for the alternator output to be delayed about 45 seconds after engine starts? Very consistent delay especially after vehicle is unused for a period of time. Voltage hovers at 12 to 12.1 volts for about 45 seconds then rises to 14.4 to 14.6 volts. Normal or not, what's the reason if this is normal?

Dave.

Dave this is just a pure guess, if it is designed to function this way. The desiels draw alot of cranking amps and have very large alternators. A delay would help control voltage spikes, allow the engine to stabilize with less load from alternator drag, and also reduce heat to the B+ circuit (Depending how the circuit is designed)wired, and starter solenoid or solenoids (at the B+ conection to keep the solenoids cooler), if there are (2)to the battery and starter possiably. The other thing it might due is not shock the batteries so hard right after a heavy load, and let them settle down first. I can see where it would make alot of sense.

Dave my 93 F250 7.3 does the same thing I ask the guy at the ford dealer here and he said all the fords did that not to worry that ishow they designed the charging system on the7.3.

The glow plugs keep drawing for a short time after the engine has started I was told.

LivermoreDave wrote:Application is 2001 F250 w/Powerstroke and automatic. My question; is it normal for the alternator output to be delayed about 45 seconds after engine starts? Very consistent delay especially after vehicle is unused for a period of time. Voltage hovers at 12 to 12.1 volts for about 45 seconds then rises to 14.4 to 14.6 volts. Normal or not, what's the reason if this is normal?

Dave.

I never noticed my 02 powerstroke doing that . I will check in a few min and see if mine does .

Thanks for the replies fellas. I noticed this situation shortly after purchasing the truck although I never detailed it until lately. I too learned of the primary, secondary battery placement and function. I have also read that alternating the batteries position once or twice a year assists in each battery's life, so I'm trying that as well. Keep the info coming, I need educated!

Dave.

I can't help you out ! Mine has a idiot light instead of a gauge! I can however check after it has set overnight and put a volt meter on it and have someone to start it while I watch the meter.

whitefield wrote:I can't help you out ! Mine has a idiot light instead of a gauge! I can however check after it has set overnight and put a volt meter on it and have someone to start it while I watch the meter.

Mine does it everytime I shut it down anf fire it back up

Bill Heard wrote:The glow plugs keep drawing for a short time after the engine has started I was told.

This is what I've read too. My powerstroke does it too.

whitefield wrote:I can't help you out ! Mine has a idiot light instead of a gauge! I can however check after it has set overnight and put a volt meter on it and have someone to start it while I watch the meter.

Mine has a factory voltmeter, although the voltmeter is without detail. I made some leads for one of my digital testers that utilize the cigarette lighter/power port accessory. This way I can sit inside and watch every step of the charging/voltage sequence.

Dave.

Dave,my 97 does the same ,but not the 99.??????

the delay is really a slow ramp up to voltage. A shock load to the belt drive causes slip a the squealling

My '02 does it more so on cold days my '95 used to do it also when cold. Was always told the glow plugs caused it when cold.

Dave I had this exact thing on my truck, I found out it was the battery cables and the green oxidation on them. I found a great little thing called (Whip) you put it on your battery cables and the green disappears right in front of your eyes. Now my charging system is almost instantly....

Its the glow plugs burnin suckin the amps , the older trucks will turn um on even after a hot start, I think somewhere in 99 they started only turning on the gp's if eot was a certain temp.

Also they keep the gp's on after startup to help w smoke, on time will depend in certain factors

Yep, It's the GPs. Mine was the same

the Coug wrote:Dave I had this exact thing on my truck, I found out it was the battery cables and the green oxidation on them. I found a great little thing called (Whip) you put it on your battery cables and the green disappears right in front of your eyes. Now my charging system is almost instantly....

Those areas are very clean Coug, I use Oxigard paste on all electrical connections which are not protected from the elements. The paste protects different materials which are joined together from natural corrosion. Thanks for the reminder!

richter69 wrote:Its the glow plugs burnin suckin the amps , the older trucks will turn um on even after a hot start, I think somewhere in 99 they started only turning on the gp's if eot was a certain temp.

richter69 wrote:Also they keep the gp's on after startup to help w smoke, on time will depend in certain factors

jbozzelle wrote:Yep, It's the GPs.  Mine was the same

Fellas I don't disagree but that's a ton of voltage those GP's are pulling out of the battery. From 12V to 14.5V for 45 seconds! How many amps do the GP's draw?

Dave.

thats about right. 200 amps will knock the volts down a good bit.

Its the GP 's Mine does it too. It's amazing how long they stay on after the engine starts. The glow plug light doesn't represent the time the GP's are on either. I pulled the wire that comes from the ecm that completes the ground to turn them on and the voltmeter worked as normal, hooked it back up and back to about 10-11 volts after start. When the GP's cycle off it's back to 14,5 volts again.

Mine dropped the voltage farther after I replaced all the GP's. I had several that weren't working.

It's normal go on to bed your old and need sleep...............  

richter69 wrote:thats about right. 200 amps will knock the volts down a good bit.

I checked mine after they all were replaced and it was right at 180 amps.............

I put a temp switch on my 95 to disable the GPs over 160 degrees.... and Blake is correct the light and actual on time are not the same.

richter69 wrote:thats about right. 200 amps will knock the volts down a good bit.

Wow ...   ... I'm surprised the battery, alternator and wiring offer any service at all!

IDT-572 wrote:  It's normal go on to bed your old and need sleep...............  

Thanks Blake, I was getting tired getting up every hour, going outside and starting the Powerstroke during this cold weather. I will sleep better tonight knowing you care ...    ...

Dave.

LivermoreDave wrote:

richter69 wrote:thats about right. 200 amps will knock the volts down a good bit.

Wow ...   ... I'm surprised the battery, alternator and wiring offer any service at all!

IDT-572 wrote:  It's normal go on to bed your old and need sleep...............  

Thanks Blake, I was getting tired getting up every hour, going outside and starting the Powerstroke during this cold weather. I will sleep better tonight knowing you care ...    ...

Dave.

  

The older trucks 94.5-97 have a 60 second GP glow time. I converted my 92 F350 cab and chassis 4x4 to a 1995 Powerstroke this fall. I figured my 5 year old CAT batteries were done but I got a nice surprise, they start the 7.3PSD for fun even when it's -15C or colder. The starter on my old IDI was on it's way out I guess.    When the GP's are lit the heater barely moves any air on high...LOL