Power Window

There are many old cars out there and there are many problems that creep in as the car starts to age. One of the problem could be the Power Window motor which operates intermittently for no apparent reason.
Checking for proper ground is the first thing to look for and also the available voltage at the motor terminals can very well hit the mark but sometimes even proper ground and nominal voltage check reveal no problem. In this case it could be the motor itself. A  replacement would be a good idea but costly and it may well be the circuit breaker integrated into the motor unit that is causing the problem.
One way to resolve this is to remove the motor housing and solder a jumper wire across the circuit breaker as shown below:

 Solder across the two terminals lying on both sides of the circuit breaker ( circuit breaker is the tapered metal piece with a round dot at the top).

As a precautionary measure, add a 10A fuse in series with the blue wire leading out of the motor assembly.

Backprobing Electronic Connectors

Backprobing electronic connectors provide a useful means of diagnosing a probable open or short circuit in any situation. However backprobing must be done carefully so as not to cause a short circuit in itself hence creating more problems. This means a very sharp, long and thin probe is ideal in this situation. A good idea is to remove the inner body of an insulation piercing clip (photo) and connect the end via a banana clip to the DMM (digital multimeter).

Angle Torque Wrench

This is an Angle Torque Tool.
Make sure that the stop rod (black color L rod) is slightly shorter than the ext bar and socket as shown below. Otherwise the socket will not sit at the bottom of the cylinder head bolt properly.
The stop rod can be placed outside of the cylinder head wall for support or it could be placed inside whichever is convenient.
This tool is typically attached to a 9½ inch ext rod and a ratchet wrench of 200Nm or more of torque capability.

Questions on Automotive Competency

Attempt to answer the following questions to gauge your knowledge on the general aspects of  automotive repair etc..  (some of the questions are tricky, hence you need to read carefully )

1. Which sensor output is the engine rpm of the car ?

     a. Coolant Temperature Sensor
     b. Wheel Speed sensor
     c. Oxygen sensor
     d. Crank Angle sensor

Simple short circuit test

The diagram on the left is a very simple and effective way of checking for short circuits in most vehicles but the battery terminal must be disconnected.

Unless you are checking for proper ground of this wire i.e. it is a ground wire, a positive swing of the multimeter indicating continuity means that the wire is somewhere grounded in its path before reaching to another component or point in the electrical path.

Do not use this test on wires which are unknown to you as it could damage sensitive electronic components.