• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Lucas strikes Again!!

Share this page

L

LoneRanger

Member
Offline
Another electrical issue-here is the sequence of events-Thanks for listening. '75 TR6-rear tail lights and dash lights go out one night on a rare evening drive-find blown fuse. Easy fix right?? Replaced fuse with Rimmer 35A. During testing, the original clear hooters rocker switch craps out, Fuse blows again, no headlights. While pulling the switch out, find 2 wires fused together, insulation torn away or separated, bare wires exposed and clearly connected. Some slight melting on the plastic casing of the switch. Put new fuse in and seemed fine, trying to rule out a short somewhere else. I have the wiring diagram from active, but I am not an electrician.
My questions to the experts are, will a new clear hooters rocker switch solve my problem or is this just the beginning of re-wiring the whole car??
What could cause the wires to fuse together and when did that occur??
Lastly, is the car safe to drive during daylight hours, until I get the switch??

Thanks again for listening, appreciate the help.
 
Get the Lucas version of the headlamp rocker switch. The original Clear Hooters switches were subjects of a recall. Having lived through that recall, it couldn't have come fast enough, as those original switches were brutally bad! Yes, the replacement was and still is Lucas, and that's a much better switch!

Beyond that switch issue, sounds as if a previous owner "had some fun with electricity" that you're now about to pay for. :frown:
 
I don't believe that the low beams are supposed to be on a fused circuit. Beside the obvious problems with the Clear Hooters, there may be a problem within the dimmer/flash to pass switch on the steering column.
 
Thanks poolboy, I thought it could be related to a problem within the dimmer/flash to pass switch on the steering column. But initially I had low beams, they crapped after I put in a new fuse and started to test everything. There is a Red/Green wire from the middle connection of the Clear Hooters, that feeds in a blue wire that runs to the low beams. The R/G runs to the fuse box.
 
That's right. The RG is bringing power to the fuse box, though, for all the other lamps that are on the other side of that fuse.
 
So could it be that I still had power for the headlights from one connection, but the middle connection R/G was dead, hence no tailights, dash lights(as an aside, is there a rheostat involved with the dash dimmer?)Even though the R/G and Blue were making contact? I'm trying to understand the root cause.
 
i am no electrician either but i will take a first pass at your questions...

1. "will a new clear hooters rocker switch solve my problem" Maybe, i suspect that the short caused the switch failure, not the other way around. fix both and test.

2. "or is this just the beginning of re-wiring the whole car" Probably not. but at this point i would do a visual inspection of all the wiring you can get to. check your connections, tie downs, grommets, anything that the wire is touching has a potential to wear a hole in the insulator.

3. "What could cause the wires to fuse together and when did that occur" i would guess wear and/or dry rot would be the cause of the wires becomeing bear...i would say that driving over a bump caused them to touch and fuse together. as for when this happened.....well you have 35 years to choose from.

4. "is the car safe to drive during daylight hours, until I get the switch". Probably...it is as safe today as it was the day before this problem happened. i do not have a TR6 schematic infront of me right now but i am guessing that if the power is disconnected to that circuit you should be fine... as long as you don't need your lights to drive.

good luck with it
 
TR631-1.jpg
 
Chappy, Thanks a ton, your responses make a lot of sense. Appreciate the effort. We get the switch on Monday, plug it in and keep the fingers crossed. I believe the power is no longer connected to that circuit, according to the diagram. Do you know if these cars had fuseable links associated with them?? Not sure how to attach files to this forum, or else I would send a copy.
 
Thanks poolboy for posting that dwg., do you know what is supposed to be represented by the small rectangles on the Blue/White wire for the high & low beams?? They appear on other areas, radio, overdrive on/off switch, etc.
 
Those are to represent the Lucar connectors.
 
I found a distinct improvement on my TR6 by disassembling the fuse box, and cleaning it up. All kinds of lights grew stronger....
 
Thanks Doc and MRV, I was thinking about buying a new fuse box, my original is a little beat up, loose connections. Might be the way to go.
 
Back
Top