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Electrical: Engine Starting, Charging
hours later and it should be virtually the same, maybe .1v less, no more.
Reconnect the battery to the car and turn on the headlights on full bright for 10
minutes and every accessory in the car...if the battery dies in 10 minutes replace
the battery. Otherwise, battery voltage should remain above 10.5 volts or so after
this test. There are load testers available in auto parts stores for about $30 or so
that will do a higher load test (couple hundred amps through a resistance load
bank) in about 10-30 seconds against a red/bad yellow/weak green/good voltage
scale. If these tests still have you with a good battery, then you just have to trace
down the current drain, circuit by circuit.
Tool Tips for Short Circuits. See the
suggestions on tools capable of rapidly locating shorts in wiring harnesses. [George
Downs] Take a fuse, remove the element, and solder an instrument light bulb
across it. With the engine off, plug it in to each circuit in turn at the fuse panel and
find the one that illuminates it. That is the circuit which is grounding your battery
and causing the drain.
Starting Problems and Battery Cable/Terminal Corrosion.
Terminal Corrosion and Starting Problems:
[Inquiry:] Car cranks strongly but will not start.
[Response 1: Jim Rothe] I've been discounting -- actually, completely ignoring --
any possibility of battery terminal corrosion, mostly because I've always had strong
cranking power. But in light of last night's incident (and the prior one time
occurrence) of starting with the help of a jump start, I'm going to re-check these
things. I'm reminded of incidents with my RX-7 last year, when I was able to crank
it strongly and it wouldn't start. I replaced the battery a few weeks later when the
starter motor started sounding weak, and then my intermittent no-start condition
miraculously disappeared. I've since found out that early rotaries tended to be a bit
more susceptible to weak sparks (compounded by old, low compression, engines)
than other cars. Food for thought.
[More Battery Cable Tips from Paul Grimshaw] The battery grounding cable on
Volvo 700-series cars fitted with the 2.3 litre engine is constructed of braided steel,
crimped to lugs which secure it in place. Over time, chassis and engine bay
vibrations may weaken the grounding wire. This often breaks at the block
connection. Furthermore, the effects of salt-induced corrosion can adversely affect
the crimped portion at the lugs--resulting in a poor electrical contact. Any ground
failure, whether total or partial, can play havoc with electronic systems and can
lead to the failure of the car's engine management computer and/or mass airflow
sensor. Given the risk of failure of this part, it's advisable to regularly inspect the
ground cable.
Preventive Maintenance. [Eric Anderson] . I work for Lockheed and spent years
chasing micro-corrosion. MicroC exists everywhere and is aggravated by substantial
temperature changes. It is a microscopic or larger film of corrosion that can build
up on both positive and ground connections with a preference to the ground
connection, however auto's positive connection are just as susceptible. Have you
thoroughly cleaned the battery connections, tightened and applied an anti-corrosive
file:///C|/Users/Steve/Documents/Volvo%20FAQ%20Updated/ElectricalStarting.html[01/13/14 10:02:47 PM]
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