2008 4Runner Electrical Issues

Bought my 4Runner off marketplace about 6 months ago. I've been having some issues with the battery draining if parked for a few days. Battery was replace, and have checked the alternator, and it is charging the battery. While driving, I'll have intermittent electrical power loss, where the engine is still running and I am able to drive, but the dash goes out (speedometer, fuel level etc.) along with AC, Power windows, and I'm not able to switch it into park, reverse etc. It does have an after market radio, and back up camera installed. My best guess is there is a hot wire somewhere occasionally drawing power and shorting everything out, but I'm not that knowledgeable when it comes to this part.

Has anyone experienced this or might know the cause? Thank you in advance! Other than that, it runs like a dream.

 

Do you have access to a multi-meter? I'm really not sure where to tell you to start, but I'd check everything. I bet the previous owner(s) had after market lights(headlights, tail lights, raptor lights, grill lights) /starters or other mod's that changed the electrical setup.

Check all the fuses under the hood and under the dash. See if there's anything jerry rigged or out of place.

 

How many miles? Alternator brushes last 150k-200k, are easy to replace, and can cause the battery to not get fully charged.

 

You need to google how to check for parasitic draw. It involves monitoring amperage draw after the vehicle has been shut down. Anything above 50 milliamp after vehicle shut down and computer has gone to sleep likely too much. If you are getting excessive draw, you can pull fuses one at a time to try and isolate the source. Logical to start with aftermarket add-ons.

 

275k

 

Toyota has a fuel fume removal system it pulls the fumes through charcoal it runs when the truck is not in use like being parked, you sometime might hear it if it's quite.
Not implying it's the item dragging down battery, just letting you know it is there.

 

Electrical problems are extremely difficult to diagnose and repair. For things that stop working suddenly, I would check all of the body grounds, particularly the instrument panel ground to body. Check the battery ground to the body at both ends. Corrosion can exist under the connection and look perfectly normal. For the battery drain after a few days I would check amp draw. You can get a multimeter that has a clamp for checking amperage. Since everything is 12 volt positive you just need to put the clamp over 1 wire to check it for draw when the ignition is off. I use this meter which is reasonably priced
https://www.amazon.com/gp/product/B07Z398YWF/

 

Welcome to the forum RedTitan

Did the previous owner disclose why the vehicle was up for sale. No saying or implying but just checking that you are not inheriting some problem vehicle. Are you located in a flood zone?

 

I tracked similar problem on a Jeep XJ and it was bad dash ground wire connection. Repaired connection and problem was gone.

 

Rich - What is the lower limit of measurement of DC amps? Can it measure down to 50 milliamps? I have been looking for a clamp ammeter that is reasonable priced and is sensitive enough to detect parasitic draw. Most of these can measure down to an amp which is 1000 milliamp. Thanks.

 

My neighbor had a rodent eat into a wire harness in the engine compartment, couldn’t see the damage because it was under the harness. Good luck!

 

The only scale for DC is 60 amp. There are reviews stating that getting accurate readings on DC current is difficult without a lab certified meter. Someone posted you can wrap the wires around the clamp several times as a multiplier.
"...show this meter begins to indicate current as low as 25mA (0.025A) were it bounced between 0.03 and 0.05, and provides meaning full measurements at 0.1A or above. Note that for low-current measurements one can loop the wire around the jaw multiple times, multiplying the reading by the number of turns".

Amazon also says there is a newer version of them clamp meter. This review is for the one I bought.
https://www.amazon.com/product-revi...terByKeyword=current+range#reviews-filter-bar
"Fantastic little multi-meter with clamp-on AC/DC Current Measurement" [scroll down and look for this title]

 

I was able to diagnose my parasitic draw with the UNI-T 210e clamp meter. Pretty good little meter.