For 1990-2009 cars

## Battery Hydrometer Displays Dark or Yellow Dot Abnormal Result

Caution: Batteries produce explosive gases. Batteries contain corrosive acid. Batteries supply levels of electrical current high enough to cause burns. Therefore, in order to reduce the risk of personal injury while working near a battery, observe the following guidelines:

• | Always shield your eyes.

• | Avoid leaning over the battery whenever possible.

• | Do not expose the battery to open flames or sparks.

• | Do not allow battery acid to contact the eyes or the skin.

- | Flush any contacted areas with water immediately and thoroughly.

- | Get medical help.

Molded into the top of the maintenance-free battery is a built-in temperature compensated hydrometer. Make sure that the battery top is clean when observing the hydrometer. Use a flashlight to observe the hydrometer in poorly lit areas. Do not produce any sparks. Use this hydrometer with the following diagnostic procedure.

Under normal operation, one of the following three indications will be observed:

1. The green dot is visible (A).

• | Any green appearance in the hydrometer is interpreted as a green dot.

• | The green dot means the battery is at least 65% charged and is ready for testing.

2. When the green dot can not be seen (B). The charging is below 65 %.

• | If there is a cranking complaint, refer to generator diagnosis for further testing.

• | To check the charging system for excessive draw, refer to Parasitic Load Test.

3. The dot appears clear or light yellow (C).

• | A diagnosis can not be made at this fluid level.

• | A clear or light yellow dot means that the fluid level is below the bottom of the hydrometer.

The following can cause a low fluid condition:

• | Overcharging

• | A cracked battery case

• | Tipping the battery

A battery found with a low fluid condition can indicate a high charging voltage, caused by a faulty charging system. The charging system must be checked for specified output. The electrical system must be tested for a parasitic drain. Refer to Diagnosis of the Charging System.

Replace the battery when there is a yellow or clear hydrometer along with a cranking complaint.

## Battery Hydrometer Displays Dark or Yellow Dot Normal Result

#### Visual Inspection

1. Before performing the load test, visually inspect the battery for obvious damage, such as a cracked or broken case.
2. Repair the cause of any damage or replace the battery. Refer to Battery Replacement .

#### Hydrometer Check

1. If the green dot is visible (A), perform the load test. Refer to Battery Load Test .
2. If the green dot is not visible (B), charge the battery. Refer to Battery Charging .
3. If the dot is clear or yellow (C), replace the battery. Refer to Battery Replacement .