Hiya guys, my truck ran into some problems after dealing with its first cold morning. My 1990 V6 4runner has been a California car all its life, and it's never spent much time more than 100 miles from the coast, so it's never seen really cold weather before. I decided to drive it to Salt Lake City to start off a road trip, and spent the night in a sleepy little town in Eastern Nevada, Elko. It got darn cold last night, and I guess my truck's not too happy about it. It was running great the night before. Now, though:

1) the battery gauge on the dash goes off the scale when I fire it up and try to drive it. It's related to load, so the more gas I give the car, the higher the gauge goes. The only way to keep the gauge down (a little) is to run a bunch of electrical things, like putting the heater on full blast, keeping the lights on, that sort of thing.

2) The car told me it was overheating this morning, although the engine was still cool. Still, coolant started spewing out and the radiator was plenty hot. It was odd, when the load on the engine/electrical system would go up, the temp gauge would go up as well. Stuck thermostat or something?


Anyways, I'm trying to get on the road again, and I'll be taking my truck around to the local mechanics tomorrow. The only thing I've done (which didn't work) was to replace a corroded battery terminal. Any tips on what might be up? I just don't get how the truck was driving great the night before, but started having weird issues in the morning... thanks guys.

 

The first problem sounds like a bad alternator, not sure about the coolant problem.

 

a bad alternator wouldn't put out MORE electricity, it would put out less.

 

Not if the internal regulator was shot. It could put out MORE or LESS.

Do you have a proper mix of antifreeze in the rad?

 

I haven't flushed the coolant in...okay I need to flush the coolant. The regulator might be shot, but I dunno how that could've happened overnight. We'll see what the mechanics think about it tomorrow.

 

It depends how the alternator fails. Ive had the voltage regulator fail in an alternator and put out so much of a charge that the battery was boiling from being over charged, and ive had alternators just die and put out nothing.

 

just curious did the truck start right up ?? How old is the Battery ?/

In really cold weather i have seen the voltmeter up in the high end to the battery is charged back to where it needs to be .

Correct amount of antifreeze??

 

How cold was it? Your coolant may have froze and was preventing circulation. But how in the heck is your rad hot, block cold and gauge hot?

 

If your battery was corroded that could be causing your problem but not at the terminals. If the corrosion made its way up the charge wire to the alternator (the thick one) it can break that connection, or at least cause it not to make a good connection as the wires inside are corroded.

If that happens your alternator could start to run at full output and will causing havoc on your vehicle at is could be putting out as much as 18v and many things in your truck will freak out with that much voltage. If you have the radio on and give it gas, therefore increasing the output of the alternator, does it shut off. Most stereos have overvoltage protection and it would turn itself off as to not burn up.

I would change that wire if you had a bad corrosion issue, even if that is not the problem, it likely will be in the future when corrosion has introduced itself.

 

Super-high voltage could fry your ecu, so don't run it and get that alternator checked, off the vehicle. Battery too.

For the coolant:

https://www.yotatech.com/forums/f116...nt-faq-192781/
https://www.yotatech.com/forums/f116...-flush-198530/