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TR4a Wiring Diagram

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Can anyone point me in the direction of a decent resolution wiring diagram for the TR4a that will blow up to A3 size and remain clear? I've not found one in the workshop manual....

 

Many thanks

 

David

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Guys, be careful with the Advanced Auto Wire diagram for the TR4a. I (and others) have found some discrepancies, (at least on LHD cars in the US).

 

One regards the lighting switch on the column. Here is how my lighting switch is wired:

- switch white/blue to harness double connector with two white/blue wires (going to high beams and high beam dash indicator). This is for momentary high beam flash.

 

- switch brown wire and switch brown/blue wires to harness double connector with brown/blue wire. This goes to 12 volt source.

 

- switch blue wire to harness single connector with blue wire. This goes to the dimmer switch.

 

- switch red/green wire to harness single connector with red/green wire. This goes to fuse block.

 

Note that the AAW diagram also shows a green/brown wire going from the switch to the fuse block. On my car this wire does not exist. My car only has two solid green wires coming out of the fuse block, (to voltage reg and brake lights) as indicated in the AAW diagram.

 

Jim

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well that explains a few things......I’d be grateful if you could indicate the other discrepancies - I’m also working on a US model

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Ricky30dk,

On my car, the two discrepancies I found (as I mentioned above) were the wiring of the light switch, and nogreen/brown wire from the lighting switch back to the fuse block.

I tried to attach an updated wiring diagram I drew of the lighting switch, but when I tried to upload a picture of it, the system said the file was too big. Not sure how to get around that.

Jim

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Some years ago, Pete Cox supplied me with a set of wiring diagrams for TR2-4A and another set for TR250-6 (the TR6 has a great many sheets because of the innumerable changes made to suit the American market).

The diagram for the TR4A shows negative earth. The set of diagrams for TR2-4A is 116kb, so I cannot upload it here.

Ian Cornish

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I fiddled with the image and got the file size down enough to upload. Please bear with my scrawl; those are U’s (blue) and not V’s in the color codes.

Also I should have mentioned that mine is a US spec car with negative ground, so I don’t know if that’s the reason for the discrepancies.

Jim

 

7A6ED327-797F-4910-9772-A2738EEC64BA.jpeg

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The 4a negative or positive earth debate has come up many times on here and still isnt clear, my 4a was definitely positive earth but it was a US model, it seems that the change to negative may well have taken place sometime during the production run but its not documented in spares catalogues or in the workshop manual which normally only shows a TR 4 wiring diagram anyway.

Stuart.

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Many thanks for your useful comments, all.

I have spent some time converting the AAW diagram to an editable format and have this in MS Powerpoint if anyone would like it. I thought it would be useful as I intend to make a number of changes to my wiring.

Let's see if I can upload it, but in any case, here's a snapshot of where I'm up to so far. I haven't error checked it yet and I'm still stuck with how to connect the Smartscreen unit, but I wanted to share as it's taken me AGES and involved a lot of swearing......plus one of you might spot some silly mistakes ; )

Also some pics of my modifications - yes, I know it's a TR4 dashboard....it was what I could get at the time.....the hole for the rheostat came in useful though......

 

TR4A wiring diagram.pptx

Wiring diagram.PNG

dash.jpg

dash2.jpg

dash3.jpg

dash4.jpg

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