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TR2/3/3A Wiring diagrams anyone??

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GlennC

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Do any readers have access to a correct wiring diagram for a late 59 Triumph TR3A (Comm no. is 65421) I have seen several conflicting diagrams and having recently replaced my harness I am regularly blowing the A1 fuse. I suspect it is related to the potential need to ground the fuel gage or wiper motor. The shop manual shows a connection between the two but not on the other diagrams. The wiring harness also does not seem to support it as shown. Are there any well documented errors in the diagrams?
If so you can email me directly at GRChouinard@msn.com
Thanks
 
I don't think it is so much a matter of errors as changes made through the model run and specs specific to US models. Further complicating the question, many diagrams do not show ground wires.

You might take a look at the diagrams presented by Advance Auto Wire:

https://www.advanceautowire.com/tr24a.pdf

Certainly the wiper motor wiring changed significantly during TR3 production so that one in particular could bite you if you are working with a too early diagram.

Guess I was droning on whilst Guy got right to the point.
 
As Geo said, there were quite a few changes in the wiring along the way, which are not documented by most sources.

If you would prefer a factory diagram, I believe the one in Practical Hints 6th edition is very close to correct for your car (except that the gauges are shown in the wrong panel positions). See pg 48.
https://drive.google.com/file/d/0B2...M2U2LWJhYWUtMjEyZDgxMzUyNzUw/view?usp=sharing

I've added the control head connections for LHD in pink, and the numbers for the wiper motor connections. If you reverse the black/green and green wires at the wiper motor, you'll blow the fuse. (I just noticed that the BG legend is missing, I'll add that ASAP.)

Perhaps you know all this, but JIC :

Note that the fuse ratings are given in an obscure Lucas rating method. You can get proper Lucas fuses from the usual suspects; but if you elect to substitute common American glass fuses, they need to be rated much lower. An AGC 20 (or SFE 20) is a reasonable substitute for the Lucas 35 amp; and AGC 25 for the Lucas 50 amp.

The factory relied on the mounting to ground the fuel gauge, fuel sender, and all the rear lamps. But those grounds are far from secure, so I added individual ground wires for each to my car. At the rear, I daisy chained a new black wire to each fixture, and brought it around to the fuel tank mounting bolt (which is also where the sender is grounded). At the fuel gauge, you can just run the ground wire to the ground tie point on the back of the instrument panel. I unfortunately didn't take this photo until after it was disconnected, but you can see the ground wire on the gauge, and the tie point right next to it.

 
Great information to help me out. Thank you very much. I suspect it is wiper motor wire reversal and I will let you all know how it turns out.
 
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