rowland1980

Months back my truck mysteriously died for a few days. No lights, noise or signs of any life. Did many things and read many posts over the those four days. I really didn't find or fix anything bit on the fourth day I turned the key and ran fine. I feared since I didn't find the problem that it would arise again. Last time I had the battery checked twice.
Few days ago it happens again but this time a bunch of clicks. A mechanic fella looked at it and mentioned I need a new starter. So I bought a new battery instead. Aww life to my F150. Thing is I noticed if I have the AC it won't fire up, starter just turns. I switch it off and all other components and it fires up like normal. Could this be from a dying alternator or caused by something else? Any insight on this matter would be much appreciated.


Well went to the store and it turned out to be the alternator. First time in 7 years it left me stranded on the side of the road waiting for AAA

Trav-ler

If you take your truck or generator down to the local auto zone the can test it for you in or out of the truck.

cmgoldn

Low cranking rpms registered from the crank sensor due to excessive draw from accessories, I.e. AC compressor, alternator, pwr steering pump etc. what is the condition of your serpentine belt?

rowland1980

Its poor. Seven years when I bought it used. It's time for a new one? Would that mean it may could just need a new belt then?

I am going to have the alternator tested and at that time will buy a belt.

cmgoldn

Belts last as long as tires imho. I replace them every 2-3 years. That probably isn't your main cause of the problem but it can be a good indicator to a cause of the problem. Since you said the AC is associated with the problem, id defenetly check the compressor pressure and the belt to see if you have significant wear. If the compressor is drawing hard, due to wear or undercharge, it could theoretically cause a draw on the crankshaft but in reality it's probably several combined issues creating your problem. If you replace the belt you're out what like $20? Charge the AC, $30? Replace and service the inexpensive items first, reevaluate and trouble shoot your problem with the inexpensive first.

cmgoldn

What year and engine is your truck?

rowland1980

It's an 03 F150 4.6l XLT. So a undercharge in the AC compressor could keep the battery from charging? As of now I am taking the alternator off and later go get it tested. If it turns out good then great. I will also check the charge in the AC. Have to google into doing so. I'm a amateur learning his truck.

techrep

iTrader: (1)

Who told you an under charged A/C could keep the battery from charging ? The alternator charges the battery.. A/C has nothing to do with it.

rowland1980

If the alternator is bad and no longer charges and I put a brand new battery in, could having the AC on when starting draw power to keep the starter from starting the engine?

Another hour I'll see if it's a bad alternator or not. Kinda hoping it is for problem solved and on to the next.

JCR 56

Usually when cranking the engine everything else is kicked out until the engine starts. Have your alternator checked at an alternator shop not a parts store.