401-403 Wiring Schematic

[James McClure]

I have attached a wiring schematic I am working on. I invite any suggestions on changes, additions. From early 401's to the 403's, there appear to have been some changes; mostly color codes. When finished, I'll publish here for all interested. I cannot use the wiring on my '52 401 as a guide, as it was rewired in the seventies. Any info on the backup circuit? It's there, but no evidence of lamps at the back. P.S. The forum downsized the PDF and it is not as clear as the original. I can email the original to those concerned.

[Greg Mead]

James,
I'm not sure what the aim here is. There is of course the Wiring Diagram in the Manual which is functional I believe and of course there are the made up versions of this Loom available off the shelf here in Australia. I can only assume you are trying to improve on these. What exactly are you improving? More power to your arm if this is correct. Keep up the good work

Greg Mead

[Kevin H]

James,

Re the sizing I suspect the problem is the web site is treating the document as an image rather than a document. If you can email the original file to me I will see what can be done to make the full size PDF available on this site.

pls email webmaster@bristolcars.info

Thanks,
Kevin

PS. When you click on the thumbnail the site displays the image in a window at 60%, it you click the image in that window it will display the image in a separate browser window where it can be magnified up to 100% - 611 x 791 pixels - was this the original size?

[James McClure]

My intent is to make a color version of the schematic, and might be more realistic if there are errors in the manual version. I also wanted to do this as I am making changes to mine and wanted a starting point. I'm adding an electric radiator fan, three relays, sixteen fuses and both trafficators and turn signals. The fuses and relays will be hidden behind the dash.

[Kevin H]

the attached image should display larger

[James McClure]

And, the final PDF of this will be high definition, single page size, for those who want it emailed to them. I like doing these in color; no need to trace a line with your finger and find you've accidentally skipped to the wrong line. I already found one error, a missing red wire from the O/S running light. I also labeled a switch not noted.
Possibly the final PDF could be inserted in the tech section at full resolution?

[Kevin H]

Originally Posted by James McClure

Possibly the final PDF could be inserted in the tech section at full resolution?

Definitely!

[Michael English]

Very helpful. Just used it though to help me with a brake switch problem, and found that the brake switch label is a long way to the left of the actual switch .... so I went back to an original wiring diagram to find out where it was, then back to yours to get the colours sorted!

[James McClure]

Thanks, I will soon download the finished schematic, in high resolution PDF.

[mikesay]

James
good piece of work.
I wonder how easy it might be to show how to wire in flashing indicators alongside the semaphores (which can be problematic in today's traffic). Any thoughts out there /
Regards
Mike Say

[Michael English]

Flashing indicators: The 401 I bought recently was rewired in about 1994. It has semaphores in use, but luckily for me I find a couple of unused wires in the boot, 4 coiled up under the dash and so suspect I'll find 2 more in the engine bay. It looks as though whoever made up the loom anticipated a desire for indicators. I plan to leave the semaphors as they are, and to use these wires to rig up a completely separate indicator switch, lights and flasher unit. As yet I don't know how & its far down my in-tray. But I have bought a brown period bakelite indicator switch, which is a start! Also a landrover series 2 indicator arm which looks the right period and has a wheel, so if clamped to touch the steering column it will self cancel ... nice in theory.

[James McClure]

My 401 had been retrofitted with flashers before I owned it. I reconnected the semaphores on to the proper switch. The semaphores can't support a flasher, I believe, as you can't get a bright bulb that won't melt the orange plastic. You would also need another wire to go into the semaphore for the light and coming from a flasher unit, as you need a constant current to the solenoid that pops up the semaphore. I could have run the flashing system off an auxiliary switch. I deleted the panel light dimmer instead; inserted a multi-position switch in it's place and used the panel switch plastic button, so no change is observable.

[benn.faulkner]

I came across this thread whilst trying to determine the ease of which I could add indicators to my 403. I am new to the world of Bristols an decided to start by buying a car as a 'box of bits' (I am a glutton for punishment). I have since learned that they originally came with semaphores/ trafficators....

In answer to the flashing semaphore question, the bulbs could be replaced with LEDs, removing the heat issue in respect to an incandescent bulb. An LED flasher unit has to be wired in and then hey presto, flashing trafficators...

Another option is white rear lenses with LED tail/ stop/ indicator strips (they will fit in the original lens (I believe) and give the safety of flashing indicators without external modification.

This may be a simple view, but then again I have a long way to go before I get my 403 on the road..

Cheers

Benn

[zbigmak]

Can you please tell me whether or not you finally produced a high resolution wiring diagram?

Best Regards

George Makowski