Hi all, after listing to Car Talk in August 2010, I decided to buy a newer vehicle after a lady called in about her 1996 Rodeo which she had also not done much maintenance to. she was told she was “DRIVING A DEATH TRAP!” It was eerily similar. the Rodeo was a great vehicle for years in AZ, and now MN…two extremes for sure. anyway, I just put a new battery in, and it fired right up after the old one wouldn’t charge. likely frozen and dead. so now, after a few months of MN winter, the brake indicator like is staying on, the battery indicator is on, and the analog gauge is showing only 11 volts…and the 4wd light is on, but not engaged. I took it for a short spin, and all seemed OK, but none of the lights went off. I’m thinking loose belts or rodent trouble. Please help. trying to sell it for some $$. it’s in beautiful shape and actually ran very well until I parked in in the early fall.
Perhaps your alternator is dead or you have really bad battery terminals… A quick test for your alternator is to start the truck up…pull off the positive batt terminal…if the truck dies…your alternator is dead. If it stays running its fine. If its fine then you need to look at those connections for sure.
Hi, thanks so much for the reply. Just today, I bought a brand new battery after charging the old one didn’t take. I cleaned the terminals with the wire terminal brush at that time. I am suspicious of the alternator, or at least the belt. it might be cold and not gripping as it should. I will put a multimeter across the battery this weekend after our latest temp drop fades. High of 18 tomorrow with a low of 5! but either way, it doesn’t seem the battery is being recharged when engine is running. I know this vehicle very well…it always showed 13 volts or so. Today, new battery, 11, plus the battery indicator icon is lit up. Would you recommend disconnecting the battery or bringing it inside until I get back under the hood? It’s supposed to be above freezing or near there all week, so don’t want the new battery to freeze at all…
thanks again!
I wouldn’t suggest pulling a battery terminal to test the alternator. This was a passable test in 1970s and early 80s cars, but a 1996 has way too much electronics for this. When you pull the terminal, you’re creating a situation where you can get a large power surge that can damage the engine computer and other vehicle electronics. Pulling the battery terminal to test the alternator is a VERY bad idea on anything even relatively recent, and won’t even give you a good test–if it keeps running, it would indicate the alternator is putting SOMETHING out, but it doesn’t tell you squat about whether it’s weak or not. It’s kind of like using a match to test for gas leaks.
A better idea is to get a cheap digital voltmeter and use it to check the voltage at the battery terminals while the engine is running and significant electrical loads are on, like the headlights and heater fan. You should have approximately 13-14.5 volts. Anything less and the alternator is bad. You can get a DVM at Harbor Freight or elsewhere for under $10 if you look around. Even the Harbor Freight cheapies are plenty accurate for a test like this.
If the battery is strong enough to start the car, it won’t freeze.
Great, thanks. I have a few DVM I can check the voltage. could be alt or loose/frozen belt. Also, I’m thinking with all the indicator lights and electronics ON after sitting in a cold snowy winter, I would guess the computer has to relearn settings? so maybe my short spin wasn’t long enough to re-teach it where sensors were like the 4wd or the brake light indicator. (no, hand brake is off and has been all winter, so if stuck, it is stuck in OFF position) brakes were as they always have been and there was no pulling as if one caliper was frozen and not working…so again, I’m thinking it’s the computer and sensors…but I’m just guessing and piecing this together from all your inputs and other postings I’ve read. Thanks all…
You seem to clearly need an alternator.
But…it’s been parked in that weather since early fall? Do you have a trickle charger on the battery? Do you have either a block heater, a lower radiator hose heater, or some other type of engine heater? Did you park it with a freash and proper coolant mix? Do you have “winter mix” windshield fluid?
That Rodeo often used an alternator which was connected to the computer which would turn off the voltage regulator for various reasons. That circuit can make it difficult to diagnose. Most bench testers will not test that alternator. Also the alternator has a dedicated belt and it is often wet with oil and/or antifreeze from the filter and oil cooler that is within inches of the harmonic balancer and prone to leak.
didn’t do anything special…it’s got the proper seasonal mix of coolant for MN winters. and yes, winter mix fluid, but that doesn’t explain the blower motor not working…I’m checking fuses when things warm up and rodent damage to cable systems. the squirrels and mice have been under there hiding from the constant snow falls this year.
I seem to recall that Toyotas, years ago anyway, were wired so that a bad alternator would cause the brake warning light to come on. If the more typical reasons for that warning (parking brake switch, low fluid in master cylinder) checked out OK, next place to look is the alt.