hello everyone. i have a 1986 4runner with the 2.4 22re. for some reason with my alternator (which is new) on the truck it pushes 12.25 volts and under load it pushes 11.33 and keeps draining my battery down. Off the truck the alternator pushes a good 14 volts. I am completely dumbfounded at what the problem could be. i Checked my grounds and the next thing im going to do is change my battery main + and - wires. Another situation is it doesnt start all the time. i get the dreaded Click. This doesnt happen all the time though. If i shut my heat and/or lights off a mile or 2 before i get home and shut the truck off than the truck starts up perfect the next time i start it up. this has been happening for awhile now. The truck just recently started sputtering and dying though. At first the volts would still be low but not enough for the truck to die. Now it cant handle any power. Any ideas would help. Im really getting sick of it and this is my only DD and im a college student and i have a job and need to get this fixed asap. Thank you all

 

You will have starting issues if your system is not charging.

While it does not hurt and is a big help to upgrade the battery cables.

The one lots of people neglect and causes the most headaches is the wire coming from the alternator B terminal up to your engine fuse block.

These become old and brittle and burnt to the capacity for carrying a load is greatly reduced .

I would for sure replace that one as well 8 gauge at least.

If you have not done so the plug on the alternator harness tends to corrode and should be cleaned as best you can.

 

Thank you very much for your input. The B terminal wore is just the wire that is held on by a small bolt on top right? And can u send me a picture of the fuse block. I'm not much of a mechanic just someone that tries to fix things haha. For the plug, do I just clean off the the inside where the ( I would assume) prongs are located?

 

Just where in Pa are you??

Yes that is the one bolted to the alternator.

It goes to the fuse block in the engine compartment where it is also bolted.

I just use electrical cleaner to spray the plug real well if it is really bad I might use a small file to clean the corrosion being careful not to remove good metal.

Sorry no pictures

 

Your problem is not the battery cables; you're not charging the battery at all. (12.25v)

Where are you measuring the voltage? If you're measuring it at the alternator then your problem is absolutely not the cable from the B terminal to the fuse block - the alternator is not producing any output. If you're measuring it at the battery, then it is still very unlikely to be the cable from the B terminal, unless it is completely open (broken). In that case you need a replacement; I wouldn't bother trying to out-guess the Toyota engineers by getting an "upgrade."

If you get 13.9-15.1v at the B terminal on the alternator, you have a disconnected/broken B wire. If not, since you've checked the alternator off the truck, then you're not getting any input voltage on the 3-wire connector. When you turn the key to "ON" does the "batt" light come on? That's what it's there for; if it doesn't come on you don't have power to the alternator.

Last, there's no shame in a "guy who just tries to fix things" getting help from someone who does this for a living.

 

Thank you. I'm going to try this later and I'm from Nepa in the sweet valley area

 

I had the alternator checked from the battery at the auto parts place. And yes the battery light does always come on when I turn the key but not while the truck is running. I'm gonna try the b terminal wire replacement just cuz I have some wire laying around. When u say the the 3-wire connector you mean the connector that plugs into the back of the alternator right? And thank you very much for the help

 

I just picked up a multimeter today. Which wires should I check?