10 replies to this topic

[AlanT]

A good proportion of the problems raised on here are about dificulties in understanding wiring.

 

I spent a lot of effort, very stupidly, trying to write an explanation of how I had wired a horn-relay on a TR4A.

I forgot that one picture is worth a thousand words. Especially on wiring.

 

The originator asked where to get a wiring diagram. This isn't in my WSM.

 

So this evening I drew the circuit on a scrap of paper, in about 30secs and photographed it, with the built in camera. It needed a flip and a few colour adjustments, but was actually really quick to do.

 

This isn't the only way to wire this. Its how I did mine. There are other ways that will work just as well.

 

I am really posting ths here to encourage the use of more diagrams for explaining this kind of thing.

 

Al.

[D Murton]

If you haven't got a wiring diagram most can be found here

 

www.advanceautowire.com/tr24a.pdf

 

Dave

[tthomson]

Hi Alan,

 

I totally agree with your approach. I use various software packages to draw diagrams in colour,  using standardised components, but often a simple hand drawn and photographed sketch is exactly what is needed.

 

I agree with Dave that having decent wiring diagrams help too, and the ones suggested are great for showing connections and layout.

 

I would also add that a current flow (Ladder) diagram is often more useful when troubleshooting. Your drawing is a classic current flow diagram. It shows only the bits of interest and the supply and ground connections. It makes things very clear. I can provide ladder diagrams for all the TR range that are correct for most cars. (There are the occasional difference between what is drawn and what is found in reality - typically when models change).

 

I notice you are not a member of the TR Register and wondered if you have a specific reason for not joining? It is one of the best car support organisations and I would heartily recommend it. This forum is a example of the level of support that is available.

 

TT

[AlanT]

I've only recently had any spare time for activities such as posting on here and joining things because I am shortly retiring and am working 4-days /week. Just looking at the Register membership the other week.

 

Big wiring jobs,like a whole car, I always do by Excel.

 

But this would baffle the guys who are struggling just to get a horn to go. So I worked out a way to get through to them, I hope.

 

What causes the problem is that there is a mixture of relays with 3 and 4 terminals to be found.

 

Al.

[tthomson]

Hi Al,

 

Thanks for the reply.

 

Let us know if they fixed their problem when you have a few spare moments. It is always nice to know if things work out.

 

Kind regards

 

TT

[AlanT]

We had two guys struggle with this recently more or less at the same time. We fixed em both eventually. But it was a real struggle because so many people just don't relate to electrical problems.

 

They usually make the same mistake. They to want to know how it should "look". They don't get that how it "looks" is largely un-important, just how it connects.

 

The best one, the one that beat us all, was the fuel-gauge that showed full when empty and vice-versa. The sender had the float on the wrong-side!

 

Al.

[Peter Cobbold]

Alan,

Yes I too find drawing much faster than inputting. If there were simple freeware for straightening the lines and text on a photo of a sketch we'd have the best of both worlds.

 

Pardon me for asking: what's  'WSM'  ?  I looked it up but nothing fits (http://www.acronymfinder.com/WSM.html)

 

Peter

[RogerH]

Work Shop Manual

 

Roger

[mike3md]

Work Shop Manual?

 

Roger - beat me to it  (again)

Edited by mike3md, 09 December 2012 - 09:26 PM.

[Peter Cobbold]

Work Shop Manual

 

Roger

============================================================================================

AAAgh!  of course. They haven't logged that one, over to you:

http://www.acronymfi...spx?acronym=WSM

 

Peter

[TR Mitch]

I installed TTs relay box into my car and wanted to document the complete electrical system for future reference so used Express SCH (free to download from http://expresspcb.com/). This is what I came up with:

 

 

And the horn section ..