Volvo Coupes/Sedans/Wagons 1970-1989 Repair Guide



See Figures 1, 2 and 3

Loose, dirty, or corroded battery terminals are a frequent cause of no-start conditions. Every three months or so, remove the battery terminals and clean them, giving them a light coating of petroleum jelly when you are finished. This will help to prevent corrosion.

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Fig. Fig. 1: A box-end wrench provides a good hold on the clamp nut without rounding it off

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Fig. Fig. 2: Position the cable end away from the battery terminal when detached

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Fig. Fig. 3: Install the battery hold-down securely to prevent the battery from moving while the car is in operation

Check the battery cables for signs of wear or chafing and replace any cable or terminal that looks marginal. Battery terminals can be easily cleaned; inexpensive cleaning tools are an excellent investment that will pay for themselves many times over. They can usually be purchased from any well-equipped auto parts store or parts department. The accumulated white powder and corrosion can be cleaned from the top of the battery with an old toothbrush and a solution of baking soda and water.

Unless you have a sealed, maintenance-free battery, check the electrolyte (fluid) level frequently. Be sure that the vent holes in each cell cap are not blocked by grease or dirt. The vent holes allow hydrogen gas, formed by the chemical reaction in the battery, to escape safely.

Check the battery electrolyte level at least once a month, more often in hot weather or during periods of extended operation. The level should be maintained between the upper and lower levels marked on the battery case, or to the split ring within the well in each cell. If the electrolyte level is low, distilled water should be added until the proper level is reached. Tap water is to be avoided if possible; the minerals it contains can shorten battery life by reacting with the metal plates inside the battery. Each cell is completely separate from the others, so each cell must be filled individually. It's a good idea to add the distilled water with a squeeze bulb to avoid having electrolyte (sulfuric acid) splash out.

Cars that are regularly driven at highway speeds over moderate to long distances may require battery service more frequently. Constant charging of the battery will cause some water to evaporate.

At least once a year check the specific gravity of the battery electrolyte. It should be between 1.22 and 1.28 at room temperature. A reading of 1.00 or slightly above indicates nothing but water within the battery. The electrical process has stopped and its time for a new battery. You cannot successfully add acid to a used battery. If water is added in freezing weather, the vehicle should be driven several miles to allow the water to mix with the electrolyte and prevent freezing.

If the battery becomes corroded, or if electrolyte should splash out during additions of water, a mixture of baking soda and water will neutralize the acid. This should be washed off with cold water after making sure that the cell caps are tight. Battery fluid is particularly nasty to painted surfaces; work carefully to avoid spillage on fenders and other painted bodywork.

If a charging is required while the battery is in the car, disconnect the battery cables, negative (ground) cable first. If you have removed the battery from the vehicle for charging, make sure the battery is not sitting on bare earth or concrete while being charged. A block of wood or a small stack of newspapers will prevent the battery from losing internal heat while charging.

When replacing a battery, it is important that the replacement have an Cold Cranking Amps (CCA) output rating equal to or when greater than original equipment. See Engine & Engine Overhaul for details on the battery.

If you get battery acid in your eyes or on your skin, rinse it off immediately with lots of water. Consult a doctor immediately if it gets in your eyes. The hydrogen gases formed inside the battery cells are highly explosive. Never check the level of the electrolyte in the presence of flame or when smoking. Never charge a battery in an unventilated area. Never smoke around a battery being charged.


See Figure 4

Whenever a vehicle is jump started, precautions must be followed in order to prevent the possibility of personal injury. Remember that batteries contain a small amount of explosive hydrogen gas which is a by-product of battery charging. Sparks should always be avoided when working around batteries, especially when attaching jumper cables. To minimize the possibility of accidental sparks, follow the procedure carefully.

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Fig. Fig. 4: Connect the jumper cables to the batteries and engine in the order shown

NEVER hook the batteries up in a series circuit or the entire electrical system will go up in smoke, especially the starter!

Cars equipped with a diesel engine may utilize two 12 volt batteries. If so, the batteries are connected in a parallel circuit (positive terminal to positive terminal, negative terminal to negative terminal). Hooking the batteries up in parallel circuit increases battery cranking power without increasing total battery voltage output. Output remains at 12 volts. On the other hand, hooking two 12 volt batteries up in a series circuit (positive terminal to negative terminal, positive terminal to negative terminal) increases total battery output to 24 volts (12 volts plus 12 volts).

Jump Starting Precautions

Be sure that both batteries are of the same voltage. Vehicles covered by this guide and most vehicles on the road today utilize a 12 volt charging system.
Be sure that both batteries are of the same polarity (have the same terminal, in most cases NEGATIVE grounded).
Be sure that the vehicles are not touching or a short could occur.
On serviceable batteries, be sure the vent cap holes are not obstructed.
Do not smoke or allow sparks anywhere near the batteries.
In cold weather, make sure the battery electrolyte is not frozen. This can occur more readily in a battery that has been in a state of discharge.
Do not allow electrolyte to contact your skin or clothing.

Jump Starting Procedure
  1. Make sure that the voltages of the 2 batteries are the same. Most batteries and charging systems are of the 12 volt variety.
  3. Pull the jumping vehicle (with the good battery) into a position so the jumper cables can reach the dead battery and that vehicle's engine. Make sure that the vehicles do NOT touch.
  5. Place the transmissions of both vehicles in NEUTRAL or PARK , as applicable, then firmly set their parking brakes.

If necessary for safety reasons, the hazard lights on both vehicles may be operated throughout the entire procedure without significantly increasing the difficulty of jumping the dead battery.

  1. Turn all lights and accessories off on both vehicles. Make sure the ignition switches on both vehicles are turned to the OFF position.
  3. Cover the battery cell caps with a rag, but do not cover the terminals.
  5. Make sure the terminals on both batteries are clean and free of corrosion or proper electrical connection will be impeded. If necessary, clean the battery terminals before proceeding.
  7. Identify the positive (+) and negative (-) terminals on both battery posts.
  9. Connect the first jumper cable to the positive (+) terminal of the dead battery, then connect the other end of that cable to the positive (+) terminal of the booster (good) battery.
  11. Connect one end of the other jumper cable to the negative (-) terminal on the booster battery and the other cable clamp to an engine bolt head, alternator bracket or other solid, metallic point on the engine with the dead battery. Try to pick a ground on the engine that is positioned away from the battery in order to minimize the possibility of the 2 clamps touching should one loosen during the procedure. DO NOT connect this clamp to the negative (-) terminal of the bad battery.

Be very careful to keep the jumper cables away from moving parts (cooling fan, belts, etc.) on both engines.

  1. Check to make sure that the cables are routed away from any moving parts, then start the donor vehicle's engine. Run the engine at moderate speed for several minutes to allow the dead battery a chance to receive some initial charge.
  3. With the donor vehicle's engine still running slightly above idle, try to start the vehicle with the dead battery. Crank the engine for no more than 10 seconds at a time and let the starter cool for at least 20 seconds between tries. If the vehicle does not start within 3 tries, it is likely that something else is also wrong or that the battery needs additional time to charge.
  5. Once the vehicle is started, allow it to run at idle for a few seconds to make sure that it is operating properly operating.
  7. Turn on the headlights, heater blower and, if equipped, the rear defroster of both vehicles in order to reduce the severity of voltage spikes and subsequent risk of damage to the vehicles' electrical systems when the cables are disconnected. This step is especially important to late model vehicles equipped with computer control modules.
  9. Carefully disconnect the cables in the reverse order of connection. Start with the negative cable that is attached to the engine ground, then the negative cable on the donor battery. Disconnect the positive cable from the donor battery and finally, disconnect the positive cable from the formerly dead battery. Be careful when disconnecting the cables from the positive terminals not to allow the alligator clips to touch any metal on either vehicle or a short and sparks will occur.