Hi all,

It occurred to me that this may be of use to some people out there. This happened 3 years ago....sorry for the delay, but just found my old rubber cap which reminded me! 2007 Hawk STi Spec D.

All that caused the battery, handbrake, CEL and rear diff temp lights to come on was the bolt under the red rubber cap on the alternator had worked loose.

The bolt and washers appeared white and chalky, and the rubber cap was quite literally toast. Clearly a fair amount of arcing had been occurring.

Not sure how long it had been happening, but found the fault very quickly after the dash lights. Although in the speedo pic below I was stationary, the handbrake wasn't on. The handbrake light was on in another (blurry pic my mate took at 40mph)

I would understand it if it was just the battery light, I mean....rear diff temp? WTF!!

At the roadside before I knew what on earth was going on, I touched the rear diff (handbrake now well and truly on!) which was only the usual warm temp. I knew the diff oil was good and so was the level, no leaks. Headed for the battery etc, found what the cause was, but didn't have a socket or anything on me. I also wasn't getting any electrical / burning smells.

Short drive home and all sorted - I disconnected the battery, cleaned the terminals going to and on the alternator, nipped down the bolt, and all the lights below vanished upon the next start up.

From what I found, the bolt wasn't much more than finger tight really, and a fair amount of side to side wiggle play on the main power lead. Least it made finding the fault easy.
Replaced bolt / washers and rubber cap etc a few days later.

Worth a check, and simple to nip up if needs be, no grease. Just disconnect the battery first of course :

 

Good advice. I had the exactly the same on my spec d, with the random fault lights and the cause was the same, loose alternator terminal nut.

 

 

Sounds like it might be worth using a lock nut or some quality thread lock.....