Hey everyone, so I have a strange problem with my 87 pickup. Whenever I have my lights, heat and wipers on, occasionally my alternator belt will squeal like crazy and the reading on my battery gage would jump down in half. My RPMs will also fluctuate and sometimes while driving I would get a "jerking" motion. At first I thought this could be an alternator problem but after getting it tested, it was fine. So it led me to believe I had a bad ground somewhere, so I replaced the grounds and still have that re-occurring problem. Any idea what's going on?

 

Your sure your alternator belt is adjusted correct ??

It acts like it is loose when the demand goes up it starts to slip

Sounds like it is time to buy a Multi meter

 

i guess I haven't checked that yet. When researching, everything led to bad wiring so I went there first. I have a multi meter, what should I be checking for?

 

Yes, check belt tension first... then ...
Good job getting a multi-meter.
Here are test points

 

Another factor is the belt itself. An old hard belt is more likely to slip, and by your description you've already confirmed it is slipping, so get that fixed first. At full load on the alt, the belt should never slip. If the belt was over tightened in the past, it could have broken the belts (the fabric/cross hatching inside the belt) and turned it more into a rubber band that stretches. Got to love growing up around the old V belt based engines. The newer style of belt is much harder to get to slip, but the conversion would be a pain and probably not worth it.

 

When I first got my pickup everything I would turn the blinker on and my volt gauge would bounce back and forth. I now have all led bulbs, ran another charging wire from the alternator to the fuse box and another wire from the battery to the fuse box and not a single problem with it since.

 

???!!!!
You bypassed your fusible link wire?

 

Keeping Firefighters from being bored across the world!!

Wire nuts perhaps ??

 

I was not aware of a fusible link wire and it runs right into the same fuse as the other wire. Ain't that what fuses are for?

 

fl to protect the fuse!

there are circuits connected to the plate at the end of the stock fusible link..

Link and image..



Iirc it's safety circuits but I'm lazy today..

 

What kind of rig are we working on Jaw?

 

That is what I wired the new one.

 

I have never understood the concept of that link in the location it's in. Does anybody know how many amps it takes to burn it? I did away with it on mine. Not trying to sell the idea but there have been so many issues tied directly back to that undersized wire and 25 year old fusible link section that I, personally, was compelled to part with it.

 

I dont by pass the Fusible Link but have wondered what it takes to burn it up. I fixed a truck that the alternator caught fire from a leaking power steering pump and another person jumped the battery wrong. Each time it blew the 80 Amp fuse and the Fusible Link did not have any damage. I am not saying to bypass it but wonder what it would take for it to do its job. Just looking to see what some of the guys with electrical experience suggest.

 

It's a slow blow vs instant blow fuse.

So 80 amps will instantly blow the primary but take several moments to burn thru the whole fusible link, worth noting it will still be damaged and should be inspected or replaced.

As noted the circuit directly connected is the headlamp. Also these are individually fused. In a collision the box could be crushed creating a short to the body or otherwise the FL would burn thru in this case as well if someone had replaced the individual fuses.

in all cases..
As a safety feature it will fail to prevent the hydrogen produced when the battery is shorted from exploding. You know the reason you're not supposed to connect jumper cables to the battery terminal, which most people ignore and is why we have dedicated jumper grounds now... It's bad news if uncontained(big boom and a fire ball), it's catastrophic if the battery explodes (as before but with the added spray of sulfuric acid and shrapnel)..

 

I got bored and went to looking for acceptable resistance of FL wire by the foot..

I was instantly reminded the the primary's are FL wire in a housing and not typical fast blow fuses..

It's covered elsewhere but might aswell be here also..

the main FL is blue color coded that's 100-120 amps depending on ambient. FL wire is designed , the sheath rather, not to burn when overloaded. This is one of the primary differences between it and random bulk wire..

 

Perfect! That actually makes sense. Every other answer I ever heard was "safety". Thanks

 

Same problem as this guy. I have an 88 3vze, but I just recently did the CS144 swap, with a new, not rebuilt, alternator. New Interstate battery as well (less than 4 months old, as they tend to go quicker living in the Wyoming sub-zero temps) It has less than 2000 miles on it, but all of a sudden, today, my volt gauge dropped to about half, all my lights dimmed for a few seconds, and my idle rpms dropped to about 500 from the normal 850. Then, it flickered back. This happened about 6 times as well on my drive home, when I was actively driving, not idling. I'm not sure what the deal is here. Tomorrow I'm going to go make sure that the belt is as tight as I can possibly make it and see if that helps at all. I'll let y'all know if that helps, but if you have any suggestions, send them my way!

 

You probably don't want to over tighten the belt, you could break the belts in it and turn it into a rubber band (slips even more and more likely to break), and the fact it tightens by a bolt adjusting system, so you can really go overboard with it easy. I'd say adjust it correctly (not sure what the official "tightness" is though).

With it happening more or less randomly, almost sounds like a bad connection, or maybe a failing voltage regulator (I've never experienced either in a Toyota yet though).

Might be my opinion, but I'd personally go with a rebuilt OEM alt vs a 100% new who knows where it's made (mexico, china?) alt unless you went to the dealer and got an OEM replacement.

Even though this thread goes along with your problem, it might be best to make a new thread, and link to this one in it as a reference to your problem. Should give your post more and better exposure to more people.

 

Most likely this. ^^^ Most Toyota parts are bullet proof. Problems are often caused by the way they are connected or put together. Many people overlook connections, corrosion, broken/brittle wires and go straight into replacing parts. Buying new parts is fun. Chasing broken connection and cleaning them is not.