Why a good soldering iron is essential.

It’s amazing what’s ended up in my tool kit here at DriveanotherdayHQ since I decided that DIY car maintenance should be something I should learn – over the years many random brand name sockets (of all sizes and qualities) have ended up grouped together in a massive tool tub in the shed. Of course I can never find the right socket at the right time which is why I always have a set of ring spanners on standby in the hope they’ll be of some assistance…

(2020 Edit: I wrote this post roughly 6 years ago and in that time my humble soldering iron has had an absolute workout, doing stuff on at least 4 cars and fixing up various bits and pieces along the way. Sadly it broke the other day (possibly from being worked to death), the heating element inside cracked and now it’s no more. However I will be replacing my dead one with the exact same model as listed below.¬†Because I know how good it works, it’s still available at Jaycar for the same price (bargain!) and it definitely comes highly recommended from me. )¬†

Along with the spanners sit a couple of adjustable wrenches, plenty of zip tyres, a special socket ‘cube’ that winds brake pistons back (used once), lots of screwdrivers (again, I never find the one I’m actually hunting for when I need it), plenty of pliers, a couple of clamps, half a can of WD40, not enough gaffa tape, two saws or various sizes and even a concrete cutter (not for car DIY obviously but you never know..)

The most essential¬† tool however which has been a god send ever since I handed over the $25 for the complete kit, has been a soldering iron. I’d be up a certain electrical creek without a certain electrical paddle without it…

Soldering Iron

Sadly I didn’t learn how to use a soldering iron in high school, instead my teachers felt teaching me how to say ‘the spider is on the cat’ in Indonesian and complex equations to calculate Mars Bars stocks would be a much better idea to focus on. This is a shame because having known what I know now, I probably would’ve saved a couple of hundred dollars in the process.

Apart from seeing a couple of technicians use one while passing their desks at work, my introduction to the art of soldering came in the form of desperately needing a signal relay on a 89 Mazda Rx7 to do something, like actually indicate safely after one morning it decided to take the rest of the year off. Now I could either source another one (at $100 a pop) or attempt to somehow fix this one. Luckily after a bit of a search on Ausrotary I read up about ‘cold solder points’ and the occasional need to get rid of the old solder and apply a fresh batch. So after a quick visit to a local Jaycar store I bought the $25 Digitech starter set (complete with solder and solder sucker tool) and proceeded to teach myself very basic solder repair.

Given that the 3 pcbs that made up the relay would never been seen again unless the next owner pulled it out, I didn’t worry about how it looked after my first attempt (read: super messy), just as long as it worked. And amazingly it did. Two hours with the occasional break for a brew later and I’d saved myself $75 and gained a basic diy skill that would serve me well time and time again.


Next the wiper switch went (a very common problem with the FC3S) and I learnt all about cold solder points, removing relays and soldering new ones in. Suddenly I had all speeds of wipers back (this hadn’t happened for years til now).

Since then I’ve found my basic soldering iron fantastic for either repairing old electrical parts or patching up previous owners actions:

  • The mp3 stereo that came in my Toyota Soarer was wired into the air conditioner for some reason that escapes me. So I soldered it into the factory wiring and its been solid ever since.



  • The TT ECU had some capacitors that were well past their standard lifespan so I desoldered the old ones and put some new ones in to breathe some life back into the computer (and stop any possible strange behavior from occuring like increased fuel consumption which can happen with dodgy caps).



  • At one stage it seems my Soarer was using a piggy back ECU. I know this because the wires were an absolute exposed mess when they removed it. Now they’re properly spliced, soldered and sealed. Same with the Map sensor.

  • Don’t get me started on the tailights, that involved a lot of work getting them tiedied up to the point where the warning on the dash disapeared.

  • The central locking will last a lot longer now that it’s soldered and sealed in in properly and not held in place with taped wires.

Basically if you’re working with car wiring, car pcbs and faulty switches, a decent soldering iron repair will last a lot longer than something taped up or quickly twisted together..

So apart from a steady hand, what soldering iron do I need for basic car DIY?

Thankfully not an expensive one with multiple heat options, an elaborate stand and a price tag that could net you a couple of new tires instead – but I would also avoid anything found in a cheap store in the dodgy hardware section. Personally I’ve found the 20w with 130w turbo button does everything I need when it comes to working on cars. Start at your local electronic parts store and investigate the hobby entry level soldering irons, preferably ones that come in a handy kit form (you can always buy things like soldering wick and more flux later). $25 to $50 is a great price range to start, especially if you can repair switches and the like to save yourself plenty of coin in the long run. Obviously practise on a spare pcb or bit of throwaway tech as you build your confidence up, the last thing you need is to destroy your project completely by putting a hot soldering iron right through it..

Something like this would be more than enough to get you started and contains all you need.

Just be aware that when you do get to the level where you’re fairly good at resoldering and tidying up car wiring, expect a lot of requests from mates and other family members to take a look at their cars to ‘see what you can do’..

Helpful links

How to use a soldering iron: A beginners guide

Car electrical wiring basics – Soldering

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.