Finding the source of an electrical problem can sometimes be an ambiguous process.
This spring, I had the honour of being a judge at the Olympiades des métiers et des technologies in Quebec City. Two days during which the best compete to move up to the next level and ultimately perhaps win a medal at the world competition.
The job I was given for the competition was electrical problems. What I found out from this experience is that we often don’t know where to start when we have to repair a breakdown involving the electrical components of a vehicle. And what better way than to use a problem that was brought to us at the workshop to make a link to it and even give a tip or two for the next competitors and technicians learning in the field.
Jumping to conclusions
The problem vehicle: a 2013 Jeep Wrangler with non-functioning windscreen wipers. What I saw during the competition, and what I often see other technicians do, is to jump straight to the component and start checking, to see if there’s power and ground when you activate the said component. In some cases, this can lead you down the wrong path, waste time (and we all know that eight hours of work a day often goes by too quickly), and ultimately lead to the wrong diagnosis.
First point: Why might disconnecting a component not be recommended for some manufacturers? It’s very simple. Some manufacturers check the integrity of a circuit before sending power to it, to avoid causing a short-circuit.
So, with the component unplugged, you might not be able to see anything. And without knowing exactly what we need to see with our measurement, how can we decide on the next step?
Second point: I often mention that it’s always better to take 15 minutes to satisfy your curiosity before reading a manufacturer’s instructions.
Time to understand
In this situation, why not study the electrical circuit of the component that is not working? This audit will give us a very important clue as to the next steps we should take.
Is the component powered directly and controlled by switches, OR is it controlled by a module? Is it powered directly? Basic electrical circuit checks should be more than enough to find the source of the problem.
It is controlled by a module? The first check should be made with a scan tool to possibly find an anomaly code that will lead us to a diagnostic chart. And even if there is no code, as soon as there is a module involved in the equation, it is better to follow a charter or procedure to avoid unfortunate situations.
In our case, the windscreen wipers ARE controlled by the TIPM (Totally Intergrated Power Module), and we had code B2304 Wiper Park Switch Low. This very short charter led us to replace the module, which had suffered water ingress and a short-circuit.
In conclusion, I hope my two little tips will help you with your next repair!