Two under dash wiring issues

  1. I’m wiring in a new handbrake warning light and cannot get the light to come on. I have tested the light bulb and socket on my bench with a 12v transformer and it lights up fine. I have also replaced the handbrake switch and re-wired the brake fluid bottles. I have tested all three switches and they all seem to work - I hook up my multi-meter for continuity with the handbrake off and the bottle switches showing full, I have no continuity - thus I would expect no light to be on. When I pull on the handbrake or position the bottle switches so that they would be showing empty, I get continuity on each of the three individually. When I then connect the light bulb or the continuity meter on DC voltage, I get no light or voltage reading - with the ignition on but the car not running.

  2. After reading the thread on hooking up a backup brake switch and tying it the existing brake switch wiring (see this thread). I’m fairly sure that I found the two green/purple wires in a connector with one green/purple wire and an open slot. When I connect a wire to that slot and another jumper to the number 6 fuse section (green side), not only do I not get the brake lights to light, my multi-meter detects no voltage with the ignition on. Again, am I doing something wrong? Shouldn’t the brake lights work with just the ignition switched to on, but the engine not running?

Power has to be on
Is the switch GROUNDED?
Good luck
Gtjoey

Grounded yes. By power on, do you mean engine running, or just ignition switch turned to accessory?

Ignition switch
Gtjoey1314

Is your code prong at 6 lose or cracked
They are terrible you know
Move the wire to another prong on 6

Got the brake light switch to operate properly. But still can’t figure out the handbrake light, gonna re-trace all my wiring and the switches.

Great
I got my mute fixed all good!
Gtjoey13-4

I have solved the handbrake light problem. It was a bit more complicated by the fact that the PO had apparently been messing with the wiring in order to fix the inoperable handbrake light. In the process, he had one wire attached to the light bulb which was the grounding wire. The white wire, which according to to the wiring diagrams continuously powers the bulb, the switches when tripped introduce the ground, was connected to another light bulb and its wire was left loose in the upper portion of the dash. I was able to spot the loose wire since I have the dash cover off for other reasons (threading the new heater and vacuum pipes).

Once I connected the white (hot) wire to the bulb and along with the other red/green wire (ground) the bulb lit perfectly when the hand brake was applied and when the bottle switches were activated.

Back in December I had to replace the handbrake switch and spring since it was rusted and corroded beyond repair, is when I first opened up the handbrake light since it wouldn’t work with the new switch. I have to admit that @Michael_Frank pointed out to me that I was missing a white wire and even posted the diagram. (post 11) and at the time I dropped this project and moved on to something else. Tonight, when I pulled out my wiring diagram to review the wiring for the light and saw the white wire listed, I recalled his advice and went out searching for the white wire. That’s when I found it plugged in somewhere it didn’t belong and found the correct wire for that light dangling. All is well now…thanks again @Michael_Frank

Great job a simple test light in an Etype goes a long way
Your wonderful
Car was on the cover of Welsh Jaguar calendar correct?
Gtjoey

We should start a thread about what dumb PO‘s have done…

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Don’t forget. At some time in the future we will all be dpo’s.

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There is a distribution in all things, some of us are dumber than others!

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That may be true but no matter what the next owner will refer to you as the dpo or even worse!

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Not always true. I bought my 250 SL in 2007 with 150K miles on it. The PO had it 35 years and 100K miles if I recall. He puts me to shame. I’ve maintained the car, but he kept it and serviced it to keep it in the spectacular shape it was in when I got it.

My four other POs, well…

I’ve been documenting all my updates, kept receipts, even kept most every old (original) part I’ve taken off, except maintenance type parts, that will go with the car when I done with it, or just when I done and gone. I’m doing my best to not be a DPO. I’ve restored/refurbished other non-Jag’s and when I sell them and provide the new owner the documentation, installations sheets, parts, etc. they are usually blown away. I hope that no new guy to JL in the future isn’t talking about me and this car…

What ever happened to the led blinkers did you get it to work.?

Not yet. But in reading the thread by @Bfastr there was mentioned of a flasher relay from a UK source that permitted the mixed environment of incandescent and LED, but didn’t make the “clicking” sound. I ordered two of them and will be giving them a try.