Mystery electrical fault

My wife’s 2003 Highlander periodically will not start. It acts like the battery is dead and will not start. Once connected to a portable battery, it starts easily and runs for days or weeks for it happens again. I took the battery out - it was ok. Took it to shop, they found nothing. Somehow my wife thinks it is my fault. What do I do?

When You Connect The Portable Battery Are You Following Recommendations And Connecting Any Of The Wires To A Remote Location, Not directly To The Battery ?

If that is the case, I’d suspect a bad wire connection somewhere between your Highlander’s battery and the opposite ends of the battery cables, where they attach at the starter or an engine ground, etcetera.

Next time it doesn’t start, I’d use just one standard jumper cable and connect from the car battery’s Negative terminal ( - ) to a good clean engine ground without using the portable battery. If it starts then you’ve found a bad ground wire on the car and the other cable ends should be cleaned.

The shop probably found nothing because this is an intermittent problem and unless they catch it in the act they won’t find anything.

As to the “Somehow my wife thinks it is my fault. What do I do?” , You’re on your own there.


Isn’t it always the husbands fault with these kind of problems. At least it’s his problem anyways.

I suggest you clean the battery connections even if they look ok. If that doesn’t help then try starting the engine with the shifter in Neutral to see if there is a problem with the neutral safety switch.

I took the battery out and had it tested to eliminate it. When I returned it to the car, I cleaned the post and the cable so I don’t think the problem is there. I hadn’t thought of the neutral safety switch and will give that a try. Thanks