91 f-250 7.3 IDI fast crank with new starter and batteries goes to extremely slow
 

Well guys, I've owned her for about a year now. Love the truck, seems like one thing after another though. So anyway, I'll attempt to make a long story less long. truck sat most winter due to bad block heater plug in, put that in a few days ago. Never did test it until today. Also has brand new starter, had old one tested and it was bad, also new batteries (850cca) it was a cold 30 degrees yesterday in PA and couldn't get the truck to fire up. It's a hard HARD cold start. (Fires up first or second twist of the key in 70 degrees +.) So I killed the batteries, took them to get charged. Didn't even put them in until today. I turned the key one time this morning. Didn't want to risk killing the batteries so I decided I'd plug it in for awhile. I left it plugged in for 45 minutes and I felt around the block plug to see if it was warm, it was. So I unplugged my extension cord. And went to start the truck. The motor turns fast and fine, like normal, fired almost right up but died out. So I shut the key off and go to turn it again. It turned extremely slow! It turned so slow it was like completely dead batteries. so far I have checked batteries both reading 12.3 with multimeter/ test light. Have tried to jump the starter, still turns slow. I cleaned all battery terminals and leads. I looked at both of the grounds from the negative leads from the batteries. They both ground into the front end of the block, however that's where I stopped because I ran out of daylight! Please any info or ideas would be greatly appreciated. I am fairly new to diesel. So I'm not sure what could have caused this!
Thanks in advance.
Nick

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Forgot to add that the grounds to the block from the neg battery terminals both looked good and soild from a wiggle test, I'm off tomorrow so first thing I'm going to do is pick up there where I left off.

Bet you that positive cable is toasted, I would replace it just as a preventative maintenance. Go as thick as you can get it.

Thank you dortiz! Your input is greatly appreciated. Is there any way to know for sure that it's shot? I am going to mess with the grounds this afternoon, and if that's not it. Then I'll be replacing the positive cable. Thanks again.

Could check it for resistance, or cut open the heat shrinking to check the condition of the wire, but you would need to replace it after that lol

I've tested the positive cable from the end of the ignition (at the battery) all the way to the starter. With a multi meter. Getting all solid reads of 12.0-12.3. Messed with and cleaned up all the grounds. Still nothing. Don't have a clue. The positive terminal post on the starter is getting 12.0, also tested the positive cable between batteries. Reading a 12.3.

Could pull the starter, and have it tested, maybe it was a dud

The starter is 2 weeks old, it is "remanufactured" but after it started to turn over slow. that was my first guess. I pulled it and took it to napa an had them test it, it is good.

I would have my batteries load tested, even if they are newer, anything and everything can be defective.

The starter is 2 weeks old, it is "remanufactured" but after it started to turn over slow. that was my first guess. I pulled it and took it to napa an had them test it, it is good.

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Whoops, sorry about the last post, my phone is screwy. That sounds like a plan. Going to do that now.

I would replace the positive cable .... Reason ... It may get good voltage .... Do an ohms test with the cables .... Make sure there not attached to the engine or batteries... This is more conclusive evidence as to what the actual condition of the cables is in ..... 2guage or bigger Should be around 1ohm at most....

keep us posted..:c:

Dortiz, Battery loads tested good. 4x4, thank you. gonna give it a shot this afternoon. I am not exactly sure what gauge the wire is. But it is big.. Ha.. And will do! This really is bugging me. Thank you both for your input again!

Aight .. keep us posted ... will try to keep track more times a day fr your convience ... let us knw what your do and the out come ... might have more ideas ..

Also just so you know . i had several starters test "good" and when loaded they would fail ... if the wire's all test good .. insist on another starter or your money back and go else where if they refuse ... i think its the starter my self :dang:

Well, sorry for the late response. I had gotten fed up with it. Had it towed to my diesel mechanic. They told me last night the STARTER WAS BAD! Which is good news to me actually because i was starting to worry is could've been major. I am extremely pissed off at my local napa. Which are really the best parts store around me. And I called them immediately, telling them the mechanics saying the starter was bad. They said they would replace it no questions asked. But I am not satisfied because my initial hunch was it was a faulty starter. I took it out and took it to them, receipt in hand, and they would not get me a new one. I want them to pay my dang bill because If they could've just gave me a new starter I'd be $110 more rich! And waisted mine and your guy's time on a wild goose chase!!

My time is never wasted my friend ... its all good on here ... Glad your truck is running better now ...

ALWAYS WILLING TO HELP !!!!! no such thing as a stupid question ... no one knows it all ... and those that think they do .... well ....

I have a 91 also have put in 5 "remanufactured" NAPA starters in 2 years, It just eats them alive. I replaced my batteries once since I had the truck, I need to replace my starter again now. I feel your pain!!!!!

Kd ... something is wrong with the charging system if thats the case ... I have replace 1 in 5 years .... and it was an old one ....

Check your wiring from batterie to batterie, and then to starter and such .... most likley your going to not have a good enough Ground near the starter and that is causing them to short out ...... I put in a braided ground strap on the lower bolt then to frame .... electricity will always take the shorted and most direct route back to ground , the ol path of least resistance ..

very well could be from grime covering the starter and causing it to short itself

Yup ... exactly what i am refering too ... my starter lost about 3 pounds when i cleaned the old one off ...LOL

4x4, thank you SO much! I really do appreciate it!! and dortiz, you too! She's doing good. We just went on about a 70 mile road trip to where I'm working for the next week. Never skipped a beat. I think/hoping I just got a dud.. *remanufactured* starter. Hoping this one treats me better. Also, I took the dud To napa and had them Test it before I even did anything to the truck And They TELL ME ITS GOOD. At least I got the replacement starter for free. And the mechs cut me a bit of a deal AND she's starting good. So that's a win!
Thanks again fellas!!!!

Anytime ... Check out my trucks pics in my profile .... She's perdy