Electrical Problems 1997 - All kinds of confused (FIRST POST!!)

[jgcopple]

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New battery (less than a week) and new alternator (less than 6 months) and 4Runner is currently dead in my driveway. Electrical system going nuts on my last drive, won't start.

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About a week ago it was having trouble starting, nothing major I thought it might be the changing weather or because I hadn't driven it in a while. Then after work one day it wouldn't start, got it jumped and left it running in a parking lot while I went into a store (local, small, nothing to worry about if I needed to leave it running). when I came outside to go home the car was still running, but everything seemed like it was at half power. I started to put it in gear and it wouldn't budge. Pressed on the accelerator and immediately died. Got a new battery, started working fine, but the battery light stayed on almost the full time it was running, but I didn't have time to troubleshoot.

Fast forward to this week and it started doing the same thing, electronics at about half power and dash gauges going haywire (speedometer bouncing up and down, rpms showing zero while driving 40mph, radio cutting in and out, etc.). I idled it into a parking lot where I waited for a ride. The car was fine in an idle, but as soon as I pressed the accelerator the rpms would drop, and when I let off they would jump back up to normal.

Can't figure it out just browsing the other threads. My guesses are ground connections somewhere are loose and corroded, some sensor i'm unaware of is going out, or my entire electrical system is just about fried. Let me know what yall think, any direction is better than I have.

 

[Pedrojr80]

Have you test the alternator yet? If not i would problely star there. And if u dont have a machine to test it undo one battery terminal and see if the rig still runs and if it still running u might end up with more technical problem tracing wires, but if u undo one terminal either postive or negative and the rig dies you might have to take the alternator and have it test it at the autopart or replace it with a new one. But i would start at the alternator firts. If the alternator dont have enough juice the whole system is gona go crazy by not having all the voltage that is require to run with.

 

[19963.4lsr5]

The above is one way to test the alternator.

A Volt meter can be used too. With the battery light on all the time it seems like your replacement alternator failed.

 

[TheDurk]

Please tell me you didn't trade in a factory Denso alt for an auto parts store reman. What was wrong with the old alt and who installed it?

Need to check voltage at battery with key off and with engine running. I can type up a list of guesses but I prefer to troubleshoot the problem.

 

[jgcopple]

Please tell me you didn't trade in a factory Denso alt for an auto parts store reman. What was wrong with the old alt and who installed it?

Need to check voltage at battery with key off and with engine running. I can type up a list of guesses but I prefer to troubleshoot the problem.

Yes, replaced the original alt with the cheapest option at autozone. Maybe that was my first mistake.

I'll check voltage and everything else everyone's been saying this weekend. Love the feedback!

 

[nc-grayson]

Simple, but check your connections on the battery terminals. I had to replace my OEM battery terminals right after a new battery and alternator, because they weren't making good connections with the battery even though they looked perfect visually.

 

[JeepKiller]

It's most likely your alternator if you went with their cheapest option.... Never cheap out on something you rely on daily. Why don't people get that :frusty:

 

[davidch]

I suspect this caution has been issued on this forum before: disconnecting the battery to check the alternator is not a good idea.

Google disconnect battery to check alternator and you'll get nearly half a million hits. The third hit I got was from the Car Talk fellows, way back in 2003:

http://www.cartalk.com/content/do-quick-check-alternator-i-was

To be sure, this ancient test has been done on recent cars and those cars, their owners - and their wallets! - have survived.

 

[IBallEngineer]

Can't figure it out just browsing the other threads. My guesses are ground connections somewhere are loose and corroded, some sensor i'm unaware of is going out, or my entire electrical system is just about fried. Let me know what yall think, any direction is better than I have.

OK first off, NEVER disconnect the battery terminal while the vehicle is running, that does NOT tell you if your alternator is good, and it DOES run the risk of ruining solid state components, ie: regulator, ecm etc. Old wives tales should remain with old wives.

Now, you are most likely having a voltage issue, not a ground issue. Can't rule out ground completely, but the first place to look is the battery terminals. 12V with the engine off, 14+ with the engine running. If not 14+, check voltage at the alternator(large white wire) with the engine OFF. You should have battery voltage, if you don't, the problem is in that circuit. The White wire from the POS battery terminal goes to the 120A fuse in the engine bay fuse block, from there it goes to the Alternator. THAT wire can be corroded near the battery. This is a common failure an all cars, especially anything built in the last 20 years. Earlier cars took power off the starter, but not Toyotas. They've been doing this for ever.

That White wire also feeds the 30AM2 fuse, which powers your ignition switch.

 

[IBallEngineer]

I'll check voltage and everything else everyone's been saying this weekend. Love the feedback!

:doh:

 

[R Marra]

Electrical power

This might be something to check. You may have a short in your starter only way is to take it out and have it bench tested. Or if someone can suggest a method of testing while still on the vehicle. Not sure if this is the problem or not but I have seen it happen before. Ray

 

[Pedrojr80]

Dont know about toyotas but im some vehicles have different type of amps on the alternators so if you replace the alternator it might been that they have give you the wrong alternator with the wrong amps rate. Just trying to help!

 

[19963.4lsr5]

If his battery light is on the alt is most likely smoked. It's part of the voltage sense circuitry. As long as the Alt is pushing any type of current the bulb will be extinguished.

 

[MONTYMTB]

If it turns out to be the alternator, get one of these:
http://www.amazon.com/Denso-2100434-210-0434-Remanufactured-Alternator/dp/B000C5YBVC/ref=au_as_r?_encoding=UTF8&Make=Toyota|76&Model=4Runner|1005&Year=1999|1999&ie=UTF8&n=15684181&s=automotive&vehicleId=1&vehicleType=automotive
I put one in about 6 months ago and it has been perfect so far.

EDIT: I just checked, and apparently that one is for '99 & up only. Anyway, get the Denso if you have to replace it.