Lights / fuse #10 troubleshooting request
Discussion
Hey all, i have a short somewhere which keeps fusing the main lights. Here is a rundown of what i know - any help would be appreciated....
Car: 97 chim 500.
Issue: fuse # 10 blows. main beams and dash lights go out. flashing full beam still works. Indicators ok. Havnt tried horn or cig lighter.
Other info: after the lights go off / fuse blows, sometimes the dash lights flash on again for 10th sec - normally as i pull the gear leaver in to second. Have done 100 mile wet, A-road run with lights on all way, without problem. Missed a gear this afternoon and they went.
The centre console was removed in the summer to be refurbished, so i am thinking there may be a wire getting trapped during gear changes which is taking the dash lights out. But i cant see why the main lights would go out too. Especially as i seem to only have to replace fuse # 10 to get things working again.
Q: why would the dash lights go out at the same time as the main lights? But still work intermitantly ? They arnt on the same fuse ( according to the bible ).
Hope i am explaining the problem ok!
Car: 97 chim 500.
Issue: fuse # 10 blows. main beams and dash lights go out. flashing full beam still works. Indicators ok. Havnt tried horn or cig lighter.
Other info: after the lights go off / fuse blows, sometimes the dash lights flash on again for 10th sec - normally as i pull the gear leaver in to second. Have done 100 mile wet, A-road run with lights on all way, without problem. Missed a gear this afternoon and they went.
The centre console was removed in the summer to be refurbished, so i am thinking there may be a wire getting trapped during gear changes which is taking the dash lights out. But i cant see why the main lights would go out too. Especially as i seem to only have to replace fuse # 10 to get things working again.
Q: why would the dash lights go out at the same time as the main lights? But still work intermitantly ? They arnt on the same fuse ( according to the bible ).
Hope i am explaining the problem ok!
Are your sidelights working?
Like your ignition provides the power to switch on fans (the relays are continually live if you look) etc, the sidelight switch provides power to the switch for the main lights which turns on the dip/main relays. It is routed thru the steering column, the bible WD is pretty clear IIRC albeit for the earlier push button arrangement - the column switchgear is the same.
Dave
Like your ignition provides the power to switch on fans (the relays are continually live if you look) etc, the sidelight switch provides power to the switch for the main lights which turns on the dip/main relays. It is routed thru the steering column, the bible WD is pretty clear IIRC albeit for the earlier push button arrangement - the column switchgear is the same.
Dave
Thanks for your help Dave. Can i ask about the WD in the bible?
q1: where is the fuse pannel on that diag ? ( pg 270/271 )
q2: is there a map of where these blocks live and what they do ?
q3: is the long terminating 'thing' - labeled as 'dashboard' - a block feeding 12 v throughout the car ? I presume its under the dash?
cheers
q1: where is the fuse pannel on that diag ? ( pg 270/271 )
q2: is there a map of where these blocks live and what they do ?
q3: is the long terminating 'thing' - labeled as 'dashboard' - a block feeding 12 v throughout the car ? I presume its under the dash?
cheers
The fusebox is omitted on SH's wiring diag. There are some details of it on one of my sites tvr3.dspen.com, but then the wiring diag needs to be matched to the particular fusebox layout (I've done it for mine but it has also been significantly modded 
).
I'll try and draw it simply
++fuse++light sw+++ dash illum switch ++++ dash bulbs
................+
................++++++ side lights
................+
................++++++ main light switch +++
...........................................+
....................................++ dip / beam sw ++
....................................+.................+
.....................++++++++++++++++.................+
.....................+................................+
Dipped Bulbs +++++ relay ++ fuse ++ battery...........+
....................GND...............................+
......................................................+
............................+++++++++++++++++++++++++++
............................+.........................+
Main beam Bulbs +++fuse++ relay ++ battery...........+
...........................GND........................+
......................................................+
......................dash power? ++ flasher switch +++
Not sure if thats exactly correct, but is should illustrate the way things are connected
Dave
). I'll try and draw it simply
++fuse++light sw+++ dash illum switch ++++ dash bulbs
................+
................++++++ side lights
................+
................++++++ main light switch +++
...........................................+
....................................++ dip / beam sw ++
....................................+.................+
.....................++++++++++++++++.................+
.....................+................................+
Dipped Bulbs +++++ relay ++ fuse ++ battery...........+
....................GND...............................+
......................................................+
............................+++++++++++++++++++++++++++
............................+.........................+
Main beam Bulbs +++fuse++ relay ++ battery...........+
...........................GND........................+
......................................................+
......................dash power? ++ flasher switch +++
Not sure if thats exactly correct, but is should illustrate the way things are connected
Dave
Hi, just seen this thread.
I had a similar problem a few years ago and, as Spend suggests, I checked side lights and earth points first. They were ok so I continued replacing the the 15A fuse and it kept blowing.
I eventually traced the fault to the near side, back-lit numberplate bulb having blown.
That electrical circuit works in the same way Christmas tree lights did when we were kids
I had a similar problem a few years ago and, as Spend suggests, I checked side lights and earth points first. They were ok so I continued replacing the the 15A fuse and it kept blowing.
I eventually traced the fault to the near side, back-lit numberplate bulb having blown.
That electrical circuit works in the same way Christmas tree lights did when we were kids
An update to this issue:
Initial trouble shooting discoveries:
Hazards dont work.
Indicators work unless hazards switched on ( makes sense i think ! )
Fuse 10 ( the one that blows all the time ) blew with ign switched off.
Horn, Radio, wipers, full beem on flash all work.
Next - i switched the hazard switch on ( as these not working was as good a starting point as any ) and took the centre console out to check for gammy connections etc ( this was the last bit of trim to be removed before the problems started ). Couldnt see any obvious candidates, but re-taped up a few wired which looked like they have been nipped in the past. Did find a loose connection on the air circulation switch next to the gear stick.
Disapointingly i thought i'd see the two earthing points either side of the gear stick, but i guess they are actually under the hatch.
As i put the centre console back together the hazards suddenly switched on - then off again! I wobbled everything around to try and find what it was, but discovered it was my foot on touching the wires next to the ecu, that was making the connection.
So,i now in the footwell, I checked all the fuses and cleaned any relays that had any corrosion on the legs. Took all old tape off the cables, checked for loose connections and re-taped it all up again. While i was doing this the hazards came back on again. No matter how much wire wobbling i did now they wouldnt go off again ( without using the switch ). The fuse which protected them was # 6.
So everything was now working again. I tried all switches on the dash to try and get the fuse to blow, but all seemed well. While checking the external lights were all on, i discovered that with the fog light on - if i put full beam on, it goes off ! Dont know how long that has been a 'feature'...
<edit> Turns out its supposed the be that way http://www.pistonheads.co.uk/xforums/topic.asp?h=0&t=456422&hw=+%2Bfog+%2Bbeam
Took car for a drive and lights seem to be fine. No blown fuses. But no real answers either. I suppose the free connector on the air circ switch could have been shorting against something. That may explain the dash lights going of when i changed gear.
If not, i just hope that whatever the problem was doesnt appear on a deserted b road late at night.
At least the ecu wiring loom is lot tider.
Initial trouble shooting discoveries:
Hazards dont work.
Indicators work unless hazards switched on ( makes sense i think ! )
Fuse 10 ( the one that blows all the time ) blew with ign switched off.
Horn, Radio, wipers, full beem on flash all work.
Next - i switched the hazard switch on ( as these not working was as good a starting point as any ) and took the centre console out to check for gammy connections etc ( this was the last bit of trim to be removed before the problems started ). Couldnt see any obvious candidates, but re-taped up a few wired which looked like they have been nipped in the past. Did find a loose connection on the air circulation switch next to the gear stick.
Disapointingly i thought i'd see the two earthing points either side of the gear stick, but i guess they are actually under the hatch.
As i put the centre console back together the hazards suddenly switched on - then off again! I wobbled everything around to try and find what it was, but discovered it was my foot on touching the wires next to the ecu, that was making the connection.
So,i now in the footwell, I checked all the fuses and cleaned any relays that had any corrosion on the legs. Took all old tape off the cables, checked for loose connections and re-taped it all up again. While i was doing this the hazards came back on again. No matter how much wire wobbling i did now they wouldnt go off again ( without using the switch ). The fuse which protected them was # 6.
So everything was now working again. I tried all switches on the dash to try and get the fuse to blow, but all seemed well. While checking the external lights were all on, i discovered that with the fog light on - if i put full beam on, it goes off ! Dont know how long that has been a 'feature'...
<edit> Turns out its supposed the be that way http://www.pistonheads.co.uk/xforums/topic.asp?h=0&t=456422&hw=+%2Bfog+%2Bbeam
Took car for a drive and lights seem to be fine. No blown fuses. But no real answers either. I suppose the free connector on the air circ switch could have been shorting against something. That may explain the dash lights going of when i changed gear.
If not, i just hope that whatever the problem was doesnt appear on a deserted b road late at night.
At least the ecu wiring loom is lot tider.
Edited by Chimune on Sunday 6th January 17:00
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