Electrical problem

Post by **Kawa** » Wed Oct 16, 2013 11:35 am

After driving for 5 minutes of driving this morning, I noticed my 4G dash clock flicking on and off, then noticed it also seemed to dip the LED's of my S2000 clocks. It was a very momentary dip in power, like a bad connection. Still had 13.5V across the system.

After a minute of so, all was fine. Drove 20 miles to work, no problem.

Pulled into work to parked up and it started doing it again, but while stationary. This time the revs were dying too, then pick up, ok for bit, begin die. It was as though there was no power in the battery and the alternator was struggling, but voltage was reading 13.5V, nice and clean.

I know the ECU is on the same circuit as the clock and possibly my S2K clocks. Radio was not effected.

Did it with and without head lights and heaters etc.

I don't think it's the alternator. And battery connections are fine.

Any other thoughts?

Post by **Lude-dude** » Wed Oct 16, 2013 12:11 pm

could be a short or wires touching on that circuit somewhere, or earth connections?

have you just brought the car out of storage? a good run for a while might sort itself out

Post by **Kawa** » Wed Oct 16, 2013 12:24 pm

She's been on road for a couple of months now doing 40 miles a day. I will have another dig around see if there is anything obvious

mercutio · Post by **mercutio** » Wed Oct 16, 2013 8:51 pm

sounds like an earth to me

Post by **Thebusofwoe** » Wed Oct 16, 2013 9:11 pm

^^ same. I thought an earth too. Seen this kind of fault all too often and it being a earth somewhere. Just double check the battery earth points, both ends. If you could get it to do it constantly then do a volt drop test, or resistance check of earths. That might show you.

Post by **Kawa** » Wed Oct 16, 2013 9:21 pm

Found the common link...

I way to work I got stuck behind a bin lorry and reversed to go another way.

When I parked up at work, I reversed into my parking bay.

I tested this theory when I got home tonight and it did the same.

So its either my gear linkage messing with something or something in the rear lights/loom....

Post by **Thebusofwoe** » Wed Oct 16, 2013 9:37 pm

Or it could be that the engine twisting the other way is moving an earth or a wire on or near the motor?? But good job on finding a way of making it do it.

Post by **Kawa** » Wed Oct 16, 2013 9:56 pm

I'll have look about.

Thebusofwoe wrote: Just double check the battery earth points, both ends.

Where abouts are they 'both'? I should know this really!!

Post by **Gayno** » Wed Oct 16, 2013 10:10 pm

One goes to the slam panel, the other down to the starter motor

Post by **Thebusofwoe** » Wed Oct 16, 2013 10:49 pm

Just trace the earth from the battery. Also check the earths to and from the block and the body. I had a main earth on a civic that goes to the gearbox that was "dirty". Although tight it was moving just enough to brake contact. And the ecu earth is earthed on the cyl head, stupid design IMO. Had to replace the cable and bolts, was all good. Even if it looks ok just undo it, usually 10mm bolts, and look. If it looks clean and ok then refit tight.