Repairing Car Electronics

300ZX digital dash repairRepaired Digital Dash Cluster

This page about repairing car electronics is meant to open your mind to the possibilities of fixing an electrical component as opposed to replacing it.

Below I will include an example of how I fixed a digital dash problem on my old 1988 300ZX and saved myself big bucks. Repairing car electronics shouldn't be confused with an electrical repair.

That term is most often associated with wiring or connector issues. Instead we're talking about diagnosing and repairing things like automotive relays, switches, modules and circuit boards.

We put a lot of time and effort into properly diagnosing a failed electronic car part. Unfortunately, our first reaction when we reach this conclusion is to just go ahead and replace it.

This page is about going one step further and looking into what's wrong with this component. This additional step can save money on replacement parts and help prevent repeat failures of that particular piece of electronics . Besides, aren't you curious about what failed inside? I know I am.

Example of Repairing Car Electronics

Before I get into the story of my 300ZX, I recently repaired a horn that wasn't working. I did so without replacing any parts. This repair provided the motivation to publish this post.

A customers 1996 Chevrolet Lumina failed State inspection, because the horn didn't work. I used my standard diagnostic methods and found there wasn't any power at the horn.

However, every time I pushed on the horn pad I could hear the relay clicking. The fact the relay activated meant most of the circuit was intact. Nevertheless, no power flowed to the horns.

So I checked the four legs of the horn relay. We had power coming in with a good ground, yet no power coming out. This means the relay itself failed.

Instead of replacing it I decided to pull the cover off and take a look at the insides. The contacts had heavy green corrosion on them. This prevented current from flowing across the electrically operated switch.

I took an emery board type nail file and cleaned the contacts, then put some dielectric grease on them.

When I reinstalled the relay it worked just fine. In this case the relay would have only cost about $20, but the part wasn't readily available.

The happy customer was amazed at my skill level in diagnosing and repairing car problems and spread the word about my talents. Repairing the relay made the customer happy and brought in new business.

300ZX Electronics Repair

Digital dash power diagramDigital dash power module diagram

I had a 1988 300ZX in pristine condition. I considered this a hobby car.

Unfortunately, the Z had an annoying problem with the digital dash. Every time you hit a bump the display would flicker and sometimes go out. I bought a factory Nissan 300ZX repair manual to follow the diagnostic chart for the symptoms.

The digital dash received signals from what they called in the service manual, a power module. I performed an output test with my meter as instructed. I got a good power reading coming out of the module, but every time I would tap the module case the power would fluctuate.

My first instinct was to buy a replacement power module. The age of the vehicle combined with the rare digital dash option made this part very expensive. They wanted over $1,000 brand-new from the dealer.

300zx power module300ZX Power Module

I checked on popular auction sites and found a couple fore sale, but they still wanted $500 or more. I decided to disassemble the module and find out what was wrong with it.

Repairing car electronics can sometimes be easy. In this case the module issue was a simple fix. The printed circuit board had a break in one of the solder paths, caused from road vibration.

All I had to do was touch my hot soldering iron to the broken area and allow the solder to flow to complete the repair. When I reinstalled the power module I added rubber grommets in between the brackets to absorb the shock from the road and hopefully prevent a repeat failure to this expensive dash cluster.

repairing components is not always possible, because sometimes the failure is catastrophic. Circuit boards can melt and coils or resisters may not be available to replace.

I just want to open your mind to the fact that some electronics can be repaired instead of replaced. Rebuilt dash clusters and modules come from companies that took these components apart and fixed them.

Also note that the electronics found in your automobile such as printed circuits, diodes and relays are also found in washing machines and many other appliances you have in your home. It is almost always worth investigating whether repair is possible before replacement is performed.

Give this automotive electronics page a bookmark or share.

I have about 10 more pages on car electrical systems that you might find helpful. Next link takes you to the automotive electrical repair module page.

On the homepage you can get a rundown of what other types of information is covered on this website. You can also find out how to get your questions answered about individual diy car repairs.

I took an elective class in college about electrical repair. We would sit down with breadboards and learn how to diagnose and repair individual components.

This kind of training can be handy when it comes to working on automotive circuits. I think the self teaching book to the right is both helpful and unique. It covers basic electrical principles needed to repair cars.

It includes how to test and understand voltage, resistance, amperage and Ohm's Law. In my opinion it's clear and concise with enough attention to detail so people understand what it means in construction and repair of complex circuits.

You learn about tools and the proper equipment required to perform tasks. But more importantly how to decipher results from testing. In addition, this electrical book explains how to perform odd ball tasks.

Things like adding new circuits, installing aftermarket electronics and building your own wiring harness. I haven't seen this covered well in other manuals and it's huge for working on older cars and people building hot rods or resto mod cars.