no lights!!

[M-G]

Have a problem with the lights on 2000 Chim 450. Wife was driving home last week and all the lights went out when accelerating. I checked fuses and the fuse blown was in place 10 "dash lights and clock". I changed the fuse and everything was fine for 5 minutes on a drive out to check the lights were working (during the day) then the fuse blew again. I was just driving normally (tooting along).
Again changed the fuse and switched everything on to see if I could get it to blow again with an amp meter connected to the circuit. It didn't and the amp meter didn't register anywhere near the 15 amp fuse limit. I beleive the problem is with the dash lights so I have switched off the dash lights and have left them off. The clock is working and so are the head lights and have had no problems since.

I'm confused on why the dash lights would cause a problem with the lights are they wired into the same circuit? I would have thought they were wired to the main switch, with two circuits one for lights and one for dash lights?

Any clues or similar problems out there?

Whilst I can still drive at night (use the Chim daily) I can't see the insturments at night.

[Hut49]

Have you checked the connectors on the lighting switch itself? Any chance one of the wires to the switch is loose and shorting across to the dash lighting circuit?

May be way off beam (pun intended) but it's all I can think of to get some responses flowing to your question

Hutch

[Ribol]

Have no definite answer to your problem but it sounds like a good one!

On most cars the feed for the dash lights is taken from the side lights circuit. Forgetting the fuse side of things the general principal works like this, you have a main feed that goes to a light switch which is effectively an off/on/on switch. The first position is the side lights the second is the headlights. The dash lights are always on with all lights so their supply comes from the first part of the switch, as does the supply for the side lights. The dip/main selection is a changeover switch which is powered up by the second part of the light switch. This changeover switch invariably switches separate relays for dip and main. If relays are used for the headlights (they are on Chims) then it is possible that one fuse controls the lot and will take out all the lights including the dash ones. I think this explains why any of the parts of this lighting circuit can kill all the lights.

If the fault has gone by turning the dash lights off, penny to a pound there is a wire shorting somewhere near the dash light switch or behind the dash. I would start by looking near the dash light switch/steering column area and then on to the dash. I hope this may be of some help, good luck!

Ivan



>> Edited by Ribol on Thursday 17th October 20:01

[M-G]

Thanks for the responses. I'll try looking at the light switch and under the dash. Does the light switch come out without removing the top of the dash as really want to avoid this pig of a job?

[Ribol]

Sorry, never had the dash out so cannot help. From past experience no matter how pointless it seems it is always worth disconnecting the battery first if you start pulling major bits of wiring about. Beware of coded stereos!

[ascender]

I had the exact same problem on my 98 4.5. The dealer fixed it but couldn't tell me exactly what was causing the problem although they could tell me how much the bill was.

M.

[Jason F]

It could be worth getting a decent Auto Electrician to take a look and perhaps solve a few more problems before they occur. The wiring is um, well, a fairly hit and miss affair at times....