Car's been sitting for a year, so check rubber parts first

BY Jim KerrBackyard Mechanic. Oct 13 04:00 am

Question: My wife owns a 1994 Plymouth Acclaim. The vehicle is in showroom condition, but has not been started for about a year. It is stored in our unheated, attached garage. We wish to start the car up to move it around a bit, but I’m not sure about starting it after its lengthy sit. What would you advise?

— Gerald

Answer: Check the fluid levels and charge the battery before starting it and put the proper pressure in the tires. Rubber parts do deteriorate while sitting so you may want to inspect belts and hoses for cracks. Some fresh fuel will help it run and start better, but it’s not necessary. Check that there are no warning lights on the dash after starting and look beneath the car and under the hood for leaks while the engine is warming up. Let the car warm up fully by letting it run until the exhaust system is hot. This will help prevent the exhaust system from rusting out and allows lubrication to get to all seals and moving parts of the engine and transmission.

Question: I have a 2010 Mazda3 and am having trouble with starting the car after it sits for about five days. The battery is so dead it will not even crank the engine over. I have replaced the battery and had the starter and charging system checked out at my local garage and they tell me they are fine. The car is a GS model with the automatic transmission and the only addition I got with the car (purchased second-hand) is an aftermarket remote start that has never worked. If I boost the battery, the car starts right away. I suspect the problem may be with the remote start but am not sure how to check it out. Do you have any suggestions?

— Allan

Answer: From your description, it sounds like there is a parasitic drain on the electrical system when the car is parked. On modern vehicles, there are many electronic modules and computers and many of these use a slight bit of electricity when the car is turned off. Normally, these modules go into a low-power or sleep mode so the electrical drain is minimal, but it is possible for a malfunction to keep one of the modules awake so it is in a high-power mode. This will drain the battery in a few days.

The other possibility is something is switched on in the car that you may not notice, such as a glove compartment lamp or rear cargo lamp. There is a way to test for either of these problems.

The test is called a parasitic drain test and involves measuring the current from the battery when the car is off. The vehicle needs to be prepared for this test by removing the covers for the fuse boxes on the left end of the dash and under the hood. Leave the driver’s door open but manually close the latch so the car’s electrical system senses the door is closed. This provides access to the dash fuse box. Leave the hood open and unplug any underhood light.

Disconnect the negative battery terminal and place a 10-amp fused jumper and an ammeter in parallel from the battery to the disconnected battery cable. If the fuse blows, you have something on in the car, such as headlights or an aftermarket audio amplifier and it needs to be turned off. Otherwise, your ammeter will be damaged.

Most vehicles will have a drain of about seven to 12 milliamps. If it is under 25 milliamps on a vehicle with lots of options, it is still OK. A higher reading indicates an electrical drain.

Remove and install one fuse at a time from the fuse boxes until you see the drain reading drop significantly. You have then pinpointed the electrical circuit you need to investigate using a wiring diagram to find what is on that circuit. In your car, because the remote starter isn’t working, I would suspect it first, so disconnecting its electrical connections may fix your problem without having to do the parasitic drain test.

james.kerr@sasktel.net