Viva HA Lights - Fuse 4 - Thermal Interrupter Problem?

[MauroV]

Hello

Please can someone help me with a Fuse 4 problem. Fuse 4 on a HA is the headlights and tail lights circuit. This circuit should be permanently live, even with the ignition turned off. Unfortunately, while trying to repair the dashboard lights I managed to cause a short circuit which blew out the glass on Fuse 4 but not the fuse itself and now that whole curcuit, on both sides of the fuse block, is dead.

The manual says that there is a thermal interrupter which protects the headlights and which comes into action in the event of a short circuit. It also says to repair a short circuit as soon as possile or the interrupter can be damaged.

So, chances are the interrupter is damaged. Can anyone tell me where to find the interruptor or does anyone have any other ideas what might be the problem?

Many thanks for your help.

Mauro

[Bob perry]

Hi Mauro,

According to the HA manual I have, The circuit breaker is linked to Fuse 3

Not sure which yours is, right or left hand drive but, still number 3.
The breaker is up under the dash behind the instrument panel, I think.

Just have to trace the brown wire back until you find it. Suggest you replace it anyway and fit new fuses.

I'm sure I don't have to tell you, but make sure the battery is disconnected when ferreting around under there!!

If you don't have one, I can scan a wiring diagram over if it helps.


Good luck.

[MauroV]

Hi Bob

Thanks, yes, you are right. The thermal cut-out is attached to Fuse 3. I found it next to the under side of the fuse block. Fuse 3 is also permanently on and works great. Interior light, horn and headlight flasher are all good.

The brown wire coming from Fuse 3 goes into a small junction/connector and 3 brown wires come out the other side. If I shove a tester lamp into the junction box it is live, as you would expect as the horn etc are all working. But the brown wire that goes to the thermal cut-out, at the thermal cut-out connector end, is not live.

So, I'm assuming Fuse 4 depends upon Fuse 3 working correctly and doesn't get a live feed from anywhere else. So, if I attach a live Fuse 3 brown wire to the input side of the thermal cut-out it should hopefully all work. And if not then if I attach the live brown wire to the output side of the thermal cut-out then Fuse 4 should work.

I'm going to sleep on it but it must be worth a try. I mean, what's the worse that could happen?

[MauroV]

For the record, I was wrong about Fuse 4 being permanently live. It is actually fed from Fuse 3, which is permananetly live, but Fuse 4 is only live when the light switch (headlights and rear lights) are on. So it operates independantly of the ignition but depends on the light switch.

So far I've got the front lights all working and power to both sides of Fuse 4 but still no rear lights.

[Bob perry]

I think the rear lights go to fuse 4? One green and white, one red and white coming out of the light end, but the only one to fuse 4 appears to be red and white, so I assume the other one goes to switch. Haven't checked my wiring diagram properly yet!
Broken wire somewhere?

[MauroV]

Thanks Bob. It's all working again. Turns out there were 2 problems: firstly the connector that connects the 4 brown wires out of fuse 3, one of which feeds fuse 4 through the thermal cut-out, wasn't connected very well so fuse 4 wasn't live. Once that was fixed the headlights worked but the tail-lights were still off. The second problem with the tail-lights turned out to be simply dirty terminals in fuse 4.

Cheers

Mauro

[Bob perry]

Great, glad you sorted it out!