How to: Main Relay Fix

If you have ever had a problem starting you car on a hot day, or if you car will start fine sometimes and not others then you might have a problem with the main relay. You can just buy a new relay from Honda but they are expensive and a more cost effective solution is to re-solder the joints on the relay itself. This guide is based on a g2 Honda Integra but may apply for other Hondas.

How to find out if your main relay is faulty

When you turn the key to the 'on' position the engine check light should come on for around two seconds. You should hear the relay click when it turns on and again when it turns off. If you don't hear the click from under the steering column then the relay is faulty.

How to fix your relay

You will find the relay under the steering column. There are 4 screws holding the panel up, 1 in the coin pocket and 3 across the rest of the panel. Remove the screws and the front of the panel will drop down, remove the panel and put it aside.

The indicator relay and the main relay are held on by the same 10mm bolt, remove the bolt and unclip the main relay as pictured. The black relay is the indicator relay, if in doubt turn on the indicators and you can feel it click. The large green relay is for the central locking.

Pop the inside of the main relay out and take a close look at the soldering points on the circuit board of the relay. You may or may not notice they have some small cracks that are losing contact when they heat up and expand.

Take out a soldering iron and touch it carefully to each solder, you have to look very closely but you will see the solder begin to melt from the tip of the soldering iron. When you see the whole joint has melted quickly remove the iron and allow it to set again.

Be careful not to use an iron which is too hot  as you may damage the relay. As usual whether or not you decide to attempt this is up to you, I am not responsible if you damage you relay. It worked fine for me however, my car started straight away.

 

 

This website has been gradually growing since I started it in early 2002. Originally I was simply documenting modifications and repairs to my car but I decided to publish it when I began to discover others were interested in the information. If you need help or have a how-to relating to Honda B series VTEC engines, or DA or DC2R Integras you can
email me.

While all care is taken to provide correct information, mistakes are occasionally made and I cannot be responsible for any damage that occurs to readers vehicles.