Hello all, recently ( about one week) my truck has been acting up. ('05 F350 just turned 100k)
It sounds like the starter is cranking the motor over slower than normal. Today, started real slow this morning, and then when I left work I thought it wasnt going to but right before I was going to let off the key it kicked over. I brought it to autozone to check the batteries, and they said that they were ok (they checked them, but did not discconnect either one. they then tested the alternator, and that checked out. Lastly, they checked the starter during cranking, and on both batteries they said that the starter had tooo much draw and that was the issue. I just wanted to check if you guys agree with this, and what starters you would recommend. I was planning on getting a new (not reman) napa starter for $230? Let me know what you all think!!!! Thanks!!

 

Personally, I am not real big on the local auto parts stores when it comes to starters and alternators. I think you would be better off if you looked for a reputable local shop that re-built motors, starters, alternators, etc.

If you do not have a local shop that you can find, then I suppose NAPA would be as good as any. I bought one for my 7.3L from DBElectrical (internet) awhile back and it did not hold up. I then found a local electrical shop w/ a great reputation and had them rebuild the starter. So far, so good. If I had not found this shop, then I probably would have looked for the cheapest source of an OEM unit.

I do not think much of autozone checking both your batteries together. It should be done individually (disconnected). You need to re-do that test.

Since they did the battery test in such a sloppy manner, I am not sure I would trust the alternator test either, but JMO.

I would try a different autoparts store to see if you got the same diagnosis.

Be aware that poor electrical systems (batteries, alternator, unusually heavy ellectrical draw) can cause FICM (expensive) problems.

 

Sounds like basic short to power...check both passenger side battery terminals...make sure they're clean and have good connections...check the grounds from the battery to frame...frame to engine block...to bulkhead...whereever the grounds connect. Also ensure your positive wire connection is not corroded to your starter...if there is corrosion, then you may have a voltage resistance (not enough to carried to crank the starter)....start there first...won't cost you anything$$

 

When did you buy the truck? Are the batteries in the truck factory original?

 

I've had a NAPA starter for over 2 years that's built MUCH better than the factory. It has a LOT higher crank speed has never given any issues and the electrical connections at the solenoid don't break like an egg when you try to unscrew the cable. I'd recommend them to anyone, and I'm NOT a Napa person. That's one of the "cheap" quality pieces you'll ever find at Napa.

 

I'd look into batteries first. If they're more than 2-3 years, may be a good idea just for the sake of doing it, especially with the impending winter, depending on your area. Replacing batteries in 4F really sucks.

I had Advanced Autoparts test my batteries and alternator and it checked out. However their system isn't designed to test our diesel alternators. Guy is like "Rev it to 3k rpm and hold it there for a few minutes" and I was like "No." 3k rpm is damned near redline, and I should not have to hit 3k rpm to get a charge out of my alternator, considering I cruise at 1500-1700rpm.

In the end, I replaced the batteries first, then 2 months later the alternator. Starts/runs like a dream. We'll see what this cold winter has to offer though.

 

last yr i had same problem i didnt take a chance at the time i had the monie so i replaced alt,and one bat just went to auto zone its been running fine since as a suggestionopen a commercial account there its free just tell them you are a contractor they will set you up youll be suprised as to how much you save new bat and alt cost me 315.00 both
and its a 140 amp

 

just curious when i rev to 3 engine runs god but i have a vibration that doesnt seem right any thoughts

 

they are both the original motorcraft batteries which I agree should be replaced, but they also both have that little green eye that is still green. I do not believe it is the alternator because when tested it was putting out 13.6 volts to each battery at idle. I will clean all the terminals today, as I did see some corrosion on the passenger positive which I believe goes to the starter.

 

W/ batteries:

The green eye means nothing.

The voltage means nothing.

Testing both batteries when connected together means nothing.

Replacing one battery at a time is not a good practice.


Load test the batteries individually. One bad battery can cause a lot of problems - some of them expensive (can ruin alternator, can ruin FICM).

 

Agree 100 %. AZ tested both of my batteries and said they were good. One week later I had a no start. Bad battery finally was bad enough to drag down the good one. If original. tighten the belt and get new ones. You'll be surprised at the diff. anf it's 1 more prob. out of the way.

 

I probably will get new ones anyway. I was wondering, to load test the batteries do I just have to disconnect the positive cable that connects the two batteries running over the radiator?

 

IIRC the accessories are at full rated power at around 1200rpm.
While I agree that ultimately that means little, there are some quick checks you can do to try and narrow down some possible problem areas. Electrical issues are always troublesome and are not always an easy fix. A weak portion of the system can affect/damage/degrade other portions of the electrical system and end up costing $$$$$$ in the long run, so it's good to jump on problems early. I can't remember what post I read it in, but as a general rule your voltage should not dip below 10VDC when starting (measured from battery terminals). Also, have somebody rev the engine a bit (1200-1300rpm) and measure both terminal voltages. They should both read over 14VDC (nominal rated alternator output is 14.4VDC). That could indicate a voltage regulator/alternator problem or a ground problem. If the two battery voltages are noticeable different, it could indicate a battery or wiring problem. It's hard to diagnose without seeing the results and branching from there. Common issues are alternators (voltage regulators are pretty much incorporated into them now), batteries and corrosion. A bad terminal or ground connection can do more than you think. Keep your terminals clean and you ground strap connection solid and the cable in good condition.

Definitely replace the batteries in pairs. It takes BOTH batteries to crank the engine and it only takes one to leave you stuck looking for a jump start. If you only replace one, it will have to pick up the load that the other one can't provide, putting an extra strain on both batteries and shortening their life. Using batteries that are matched in performance will provide the best results and longest life.

Oh yeah, I almost forgot. If you have the original batteries, check each cell level and make sure it is full of distilled water. Low water level is a killer on performance and overall life (corroded plates don't work so well).

Just my .02

 

Also, I believe the alternator should be putting out 13.8-14.5v, mine was giving 13.6 actually when I had it tested, so I thought it was good. Kept having problems, replaced it, and bam, problems solved.

 

Just got the batteries re checked and disconnected the power between them. The one on the drivers side checked out perfect and the one on the passenger was DEAD!. Only had about 120 amps or so the guy said. So easy fix I guess, and two brand new duralast gold tops (hear decent reviews about them, and have a full 3 year warrany)...thanks for all the help all...I almost ordered a new starter!!!

BTW, the terminals were slightly corroded, I cleaned them but basically no change..