Battery Negative-Post To Chassis Connection

[yuen321]

My IS200SE is year 2000 model.

Recently, it take me long time to find where the Battery negative-post to chassis connection.
I want to find it out to check connection good or bad.

First:
I can’t find it.
I only saw one heavy lead is connected between Battery negative-post and engine block.

Later:
I found the connection until I took the Battery and the Battery tray out.
It is a L shape metal clamped to the heavy lead to engine block on one side , bolt to the chassis on other side.

The connection is bad after 15 years. Copper wires show corrosion at clamp side and bolt rusting the other side.

I don’t like this kind of connection sharing.
It maybe for cost cutting.

Fix the connection problem:
I isolated the L shape metal clamp by electric tape.

Then I replace it by a new lead “25mm2 (#4 AWG) AUTOMOTIVE CABLE” connected between Battery negative-post and chassis.

After the fix, engine run better.
Also, electric window/seat etc... move faster and better.

Very happy after this :)

[ColinBarber]

Nice find, although just restoring to original would have achieved the same result.

[steve2006]

A good post informative post with quality picture,thank you for taking the time to share your problem.

Battery and other main earth points are very important and often overlooked as a service inspection. I subscribe to Car Mechanics magazine and in this a different car is serviced each month, the one thing common to them all is to check the earth connections and if necessary "remove,clean and refit them"

Not only can a poor earth cause poor/non start situations but with today's modern computerised cars it can glitch ECUs causing strange hard to find problems.

[yuen321]

Colin: I don't want to restore it because I think the original connection allow electric noise / interference from the engine block to the chassis.

Steve: Thankyou for point out the important about earth points. Toyota/Lexus hiding it so well under the Battery tray