Working on bugs..advice please

[Cbrianroll]

Hi all. 2001, 4.0, auto, 4x4. 132,000miles. New to me…bought to be a firewood truck but my son wants it so I’m making it better hopefully. Current state, no brakes, they will be here next week, that’s easy to do. This is the stuff that isn’t as my troubleshooting isn’t the greatest. There are no check engine lights on/flashing etc. engine has a little fluctuating up and down at idle, amp gauge needle moves up and down a little too, dash lights dull and brighten in rhythm with it. I’m assuming time for an alternator, but wondering if I’m wrong since the motor is doing the fluctuating too. I have yet to pull plugs to check condition as the weather has been bad. It has a new battery, volts were 17+ when running. Advice is appreciated.
Next, transmission, only got one long drive in an the front brake was sticking and getting hot so will check more after new brakes but it only shifts when you let up on the gas and at upper speed I noticed the overdrive light was on and said OD off? Or on? I forget but I assume it is an issue. Fluid appeared high on the stick when warm, in park and idling. Filter and fluid will follow next week also but advice on issues is appreciated.
Lastly,,if there are any quirks I should know about I would appreciate it also…it is a work truck but need it safe and running so I don’t have to tow it lol.
Thank you all for reading and your patience with my rookie needs…

 

[alwaysFlOoReD]

17+ volts is much too high. I think your voltage regulator is kaput, and that is in your alternator. I'm not sure how easy it is to replace but some research should help. That might fix your idle problem.
Voltage should be regulated to 13.5 - 14.5 V.

 

[lil_Blue_Ford]

If I was in your position, I’d be looking at doing what I consider a dirty overhaul.

Brakes the whole deal all around unless the pad/shoes and rotors/drums look good, but new rubber lines and calipers/wheel cylinders for sure if you don’t know when they’ve been replaced, the rubber lines can break down inside and cause sticky brakes, I’ll do new hard lines if they look sketchy.

Tune-up: plugs (Motorcraft or Autolite double platinum), air filter (unless it’s in good shape), plug wires (I’ve run Duralast from Autozone for years, they seem to be just fine for a stock-ish vehicle), oil change if you don’t know when it was done and add a couple ounces of ATF to the oil (little extra cleaning and helps plump up seals), a Motorcraft/K&N/Mobile1 filter, new fuel filter if you don’t know when it was done. Also drop the transmission pan, check for glitter and chunks in the fluid, put a new filter and fluid in at the minimum. My preference while I’m in there is to do at least reverse servo gasket and O-rings if not a shift kit to the valve body (little fiddly and requires care and cleanliness but worth the effort). Also tighten the 2nd and 3rd bands (there’s information around here on that). I’ll also let it snort half a can of Seafoam through a vacuum line and dump the other half in the tank. Oh, and oxygen sensors only last 10k years or 100k miles and the catalyst that makes them work is “used up”.

I’ll also look over stuff like shocks and suspension bushings and stuff, change out anything I find that isn’t in good condition.

@alwaysFlOoReD nailed it, 17 volts is too high. Battery voltage off should be around 12.5 volts, plus or minus. Running you should see about 14.5 volts. Usually about 14.8 is the highest you should see and if it’s under 14 volts, the alternator is not charging or you have a massive draw.

 

[Curious Hound]

@alwaysFlOoReD nailed it, 17 volts is too high. Battery voltage off should be around 12.5 volts, plus or minus. Running you should see about 14.5 volts. Usually about 14.8 is the highest you should see and if it’s under 14 volts, the alternator is not charging or you have a massive draw.

I'm going to respectfully disagree with some of your numbers here. For the first 5-10 minites after starting, 14.5-14.8 is good. After that, the battery should be recharged and voltage should drop down to 14 or even below. 13.8 is good running voltage. High voltahes overcharge (cook) the battery and, up around 17volts could even start to make things act weird.

 

[Cbrianroll]

Awesome and thanks! Luckily my electric issue in the past had been limited, but that also means I need to learnore. I thought that was high, but …ya never know!
Slowly doing the dirty overhaul, brakes all around plus lines as the hard lines were twisted will getting the bad cylinder off, and the rubber too as I’ve had bad in the past, only want to bleed it once!
It just had an oil change, wix filter but unknown oil. I’ll do that again after the trans, plugs, etc just so i know what’s in it. Thanks guys, much appreciated!

 

[Cbrianroll]

Thanks curious hound, fortunately the guy I got it from bought it but it only sat in his yard as he was slowly getting it legal, new lights, etc. he hadn’t driven it or run it much. I will be getting an alt tomorrow..

 

[Cbrianroll]

Question, I keep seeing amp options. Is the 130 option a needed upgrade? Or is mine already 130?