Originally Posted by
Sachin
Thanks so much for your response Pizzaguy.
There is no power to either the fuse or the relay. Whilst digging around under the footwell I found a damaged and loose ground (what we would call earth) cable. I assume that the only ground cables leaving the footwell would be for the horn and for the brake signals. Since the horn works fine I think this might be the source of my problems. Is my assumption correct?
I cannot access behind this cluster of cable at all and so I thought I could route a cable direct from the relay back to a join with this loose wire. Am I right in saying that the ground from the brake switch (and hence this cable) goes straight into the relay at pin 85?
No power to a fuse is not a ground problem, its a problem with getting power to the fuse.
You MUST determine why there is no power to the fuse, that feed comes from a wafer on the ignition switch. I believe the high side of the fuse goes to one of the tiepoints (splice block 101) at the back of the fuse box, those are fed by the switch.
FIRST, make sure your voltmeter readings are valid, try measuring another point that you know is powered up to verify your meter is good. Make sure the ground you have your meter connected to is a REAL ground.
The manual shows a diode on the high side of that fuse, if the diode is burned open, you'd have no power to the fuse. It is not common, but it is possible that the diode is blown.