You may have seen an advert for a harness adaptor, or been told you need to buy an ISO adaptor. However, you may not have a clue what they do and why you would need one. Let's look at what one is. If you wish to change your car stereo, you need to purchase a new head unit. Fitting this is normally quite easy. As a general rule, swapping car radios is not as complex as, say, changing the engine! But there can be complications with audio cables or the new connectors not matching the old.
If your new car radio head unit has an ISO connector (which almost 100% do), you will need to adapt your existing car radio connector to the ISO connector - hence the need for an ISO adaptor. The ISO adaptor, also known as a harness adaptor or ISO harness adaptor, will be 2 blocks with 8 pin connectors. It can be one block with 2 matching halves or just 2 separate connectors, depending on the make and model of your car. These connectors allow your audio cables to be connected by simply clipping them into place, making the complicated fitting of car radios a thing of the past.
Although the power and speakers will be connected via the cables, you will need a different ISO adaptor if you have steering wheel-mounted radio controls. To keep this functionality in your car (which is much easier and safer than using the ordinary radio controls), you may need to ask your harness adaptor specialists which product you require. Some online stores have a function where you can input your car make and model to see the adaptor you need to purchase. You may also want to ask their trained fitters to talk you through which harness adaptor is best for your car. With an ISO adaptor, fitting a car radio is easier than ever.