GM Blazer/Jimmy/Typhoon/Bravada 1983-1993 Repair Guide




See Figures 1, 2, 3 and 4

All vehicles were originally equipped with a maintenance free battery as standard equipment, eliminating the need for fluid level checks and the possibility of checking specific gravity using a hand held tester. Nevertheless, the battery does require some attention.

At least once a year, the battery terminals and the cable clamps should be cleaned. Remove the post clamps or side terminal bolts and the cables, negative cable first. Clean the cable clamps and the battery terminals with a wire brush until all corrosion, grease, etc. is removed and the metal is shiny. It is especially important to clean the inside of the clamp thoroughly. A small deposit of foreign material or oxidation will prevent a sound electrical connection and inhibit either starting or charging. Special tools are available for cleaning side terminal clamps and terminals.

Before installing the cables, loosen the battery hold-down clamp, remove the battery and check the battery tray. Clear it of any debris and check it for soundness. Rust should be wire brushed away and the metal given a coat of anti-rust paint. Replace the battery and tighten the hold-down clamp securely but be careful not to overtighten, which will crack the battery case.

Surface coatings on battery cases can actually conduct electricity which will cause a slight voltage drain, so make sure the battery case is clean. Batteries can be cleaned using a paste made from a mixture of baking soda and water. Spread the paste on any corrosion, wait a few minutes, and rinse with water. Finish the job by cleaning metal parts with a wire brush.

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Fig. Fig. 1: Battery maintenance may be accomplished with household items (such as baking soda to neutralize spilled acid) or with special tools such as this post and terminal cleaner

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Fig. Fig. 2: The underside of this special battery tool has a wire brush to clean post terminals

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Fig. Fig. 3: Place the tool over the terminals and twist to clean the post

After the clamps and terminals are clean, reinstall the cables, negative cable last. Give the clamps and terminals a thin external coat of nonmetallic grease after installation, to retard corrosion.

Check the cables at the same time that the terminals are cleaned. If a cable insulation is cracked, broken or the ends are frayed, it should be replaced with a new one of the same length and gauge.

Keep flames or sparks away from the battery. It gives off explosive hydrogen gas. The battery electrolyte contains sulfuric acid. If you should get any on your skin or in your eyes, flush the affected areas with plenty of clear water. Always wear safety glasses to protect your eyes, but should any acid contact them, seek medical help immediately.

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Fig. Fig. 4: Special tools are also available for cleaning the posts and clamps of side terminal batteries


See Figure 5

Maintenance free batteries, do not require normal attention as far as fluid level checks are concerned. However, the terminals require periodic cleaning, which should be performed at least once a year.

The sealed top battery cannot be checked for charge by checking the specific gravity using a hand-held hydrometer since there is no provision for access to the electrolyte. Instead, the built-in hydrometer must be used in order to determine the current state of charge:

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Fig. Fig. 5: Maintenance free batteries contain a built-in hydrometer to help determine battery charge

  1. If the indicator eye on top of the battery is dark, the battery contains sufficient fluid. If the eye is light, the electrolyte fluid is too low and the battery must be replaced.
  3. If a green dot appears in the middle of the dark eye, the battery is sufficiently charged. Proceed to Step 4. If no green dot is visible, charge the battery as in Step 3.

Do not charge the battery for more than 50 amp/hours. If the green dot appears, or if electrolyte squirts out of the vent hole, stop the charge and proceed to Step 4.

  1. Charge the battery referring according to the proper charging rate (amps) for the necessary time span and rate of charge.
  3. 75 amps - 40 min
  5. 50 amps - 1 hr
  7. 25 amps - 2 hr
  9. 10 amps - 5 hr

It may be necessary to tip the battery from side to side to get the green dot to appear after charging.

When charging the battery, the electrical system and control unit can be quickly damaged by improper connections, high output battery chargers or incorrect service procedures.

  1. Connect a battery load tester and a voltmeter across the battery terminals (the battery cables should be disconnected from the battery). Apply a 300 amp load to the battery for 15 seconds to remove the surface charge. Remove the load.
  3. Wait 15 seconds to allow the battery to recover. Apply the appropriate test load, as specified on the battery label, for 15 seconds while reading the voltage, then disconnect the load. Some appropriate loads on original batteries are:
  5. 75-60 - 260 amps
  7. 78A-72 - 300 amps
  9. 83-50 - 150 amps
  11. 83-60 - 180 amps
  13. 85A-60 - 170 amps
  15. 87A-60 - 230 amps
  17. 89A-60 - 270 amps
  19. 1981103 - 200 amps
  21. 1981104 - 250 amps
  23. 1981105 - 270 amps
  25. 1981577 - 260 amps
  27. Check the results against the appropriate minimum voltage based on the battery temperature. If the battery voltage is at or above the specification for the temperature listed, the battery is good. If the voltage falls below specification, the battery should be replaced.
  29. 70°F or above - 9.6 volts
  31. 60°F - 9.5 volts
  33. 50°F - 9.4 volts
  35. 40°F - 9.3 volts
  37. 30°F - 9.1 volts
  39. 20°F - 8.9 volts
  41. 10°F - 8.7 volts
  43. 0°F - 8.5 volts


See Figure 6

When battery replacement becomes necessary, select a battery with a rating equal to or greater than the one which was originally installed. Deterioration and aging of the battery cables, starter motor, and associated wires makes the battery's job harder in successive years. The slow increase in electrical resistance over time makes it prudent to install a new battery with a greater capacity then the old. Details on the role the battery plays in the vehicle's electrical systems are covered in Engine & Engine Overhaul in this information.

  1. Carefully disconnect the negative battery cable from the battery terminal.

Always use caution when working on or near the battery. Never allow a tool to bridge the gap between the negative and positive battery terminals. Also, be careful not to allow a tool to provide a ground between the positive cable and any metal component on the vehicle. Either of these conditions will cause a short leading to sparks and possibly, personal injury.

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Fig. Fig. 6: Common battery and tray installation

  1. With the negative battery cable disconnected and out of the way, carefully disconnect the positive cable from the battery terminal.
  3. Loosen the nut and/or bolt securing the battery retainer strap or clamp. Remove or reposition the battery retainer.
  5. Wearing an old pair of work gloves or using a battery lifting tool to protect you from any remaining battery acid, carefully lift the battery out of the vehicle and place it in a safe location. Be sure to keep the battery away from open flame and to protect surrounding areas from acid.

To install:
  1. Inspect the battery tray and cables for damage or corrosion. As necessary, clean or repair the tray and cables.
  3. Carefully lower the battery into position in the tray, making sure not to allow the terminals to short on any bare metal during installation.
  5. Position and secure the battery retainer strap or clamp.
  7. Connect the positive battery cable to the battery terminal.
  9. Connect the negative battery cable to the battery terminal.