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TR2/3/3A Question on TR3 Wiring

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nealm

Freshman Member
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I'm nearing completion on a ground up restoration of a 1960 TR3A. I completed the new wiring harness and added the battery last weekend. I've got horns, lights and ignition circuits going, but I've got a short in the circuit that covers wipers, fuel gauge, brake lights and turnsignals. All but the brake lights are shorted. I'm wondering if I connected something incorrectly behind the dash. I've got the hot white wire connected at the starter switch. Any ideas?

Thanks
Neal M
TS 73289L
 
Aloha Neal,

I suspect as Andy pointed out that the problem is some where in those green wires coming from the fuse block, terminals A4. The a white wire from the ignition switch leads to the opposite side of the fuse, terminal A3 to power the circuits you are having a problem with. Other white wires from the ignition switch lead to the starter push switch and to the ignition warning light. How are the green wires that feed these circuits attached to the two A4 terminals? Particularly is the brake light circuit attached to one and the other circuits to the other. Perhaps there is a short at one of the fuse block terminals.

The next step I would try is to systematically disconnect the the green wires at each end and check for a ground. If none of the wires is shorting to ground then the fault is in a switch, flasher, gauge, etc. Work each circuit one end to the other to find the problem through the process of elimination. Good luck.
 
In particular the wiper circuit is somewhat counter-intuitive and may be inccorrect on the wiring diagram depending on what diagram you're using.

Also, the fuel gauge circuit is an easy one to get worng.
 
Thanks all. This is a new wiring harness, fuse box, etc. I saw that the wiper circuit on the standard diagram is wrong for the type of motor I have (3 wire). I have a separate connection from the loom to the wiper switch so I don't think that is the problem. I've got all the greens on the same side of the fuse and opposite the white hot wire. Behind the dash I've got the white wire connected to the ignition switch. I'm assuming that means that the green circuits won't run unless the ignition is on.
 
Your assumption is correct, they should not have power if the ignition switch is off. Reviewing the TR3A wiring diagram I have the green wire in the wiper circuit going to the motor and a black wire from the motor to the switch. When I installed a new wiring harness in my TR3A I remember I had a problem getting the wipers to work. I don't recall if it affected the fuel gauge and turn signals since I was focused on the wiper motor. As Geo suggested, that may be the first thing to check.
 
Aloha Neal,

I researched the related problem I had when I installed a new harness. The wiper motor in my car is wired like that shown on a TR4 wiring diagram. If yours is like mine, this may solve your problem. These are wipers that have a "parking" feature. When turned off the wipers continue to the parked position instead of stopping where ever they are when switched off. In this installation, the switch controls the path to ground.

Geo help me out with this information which also has a site with TR2 thru TR4A wiring diagrams.

"Actually the 'ground-switched' wiper motors were original to most TR3As but the wiring diagrams usually encountered still show the old 'power switched' arrangement... so yours may well be the original motor.

If you haven't printed off a copy, this site has a link to some good wiring diagrams for the late TR3A (and others):

https://www.britishv8.org/techhome.htm "

This is from a topic I posted 1/30/05 in the Triumph forum titled "Windshield Wiper Motor Problem". I'm sure there is a way to link it, but I don't know how.
 
[ QUOTE ]
Aloha Neal,


https://www.britishv8.org/techhome.htm "

This is from a topic I posted 1/30/05 in the Triumph forum titled "Windshield Wiper Motor Problem". I'm sure there is a way to link it, but I don't know how.

[/ QUOTE ]

Dave, that link doesn't work to well. Neal might be able to use our diagrams on our sites.

Cheers!
M
 
Thanks to all! Problem appears resolved. Can't be sure exactly what I did but my best guess is that the wiper hot wire and switch wires were reversed. I took everything apart and reconnected using the wiring diagram in the above link and now everything works. Going to fill fluids this weekend and try to start her up. Car has been off the road since 1968. Here's a before picture.
 

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Picture of progress to date attached

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That is sweet! /ubbthreads/images/graemlins/thumbsup.gif
 
Jim - Compare the door handle mechanism with the attachment. It may help to set your door handle horizontally like it should be.
 

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Color is old english white. I've got the red leather seat covers and interior panels from Heritage yet to install. The door mechanisms are not yet installed either thus the door handle position.
 
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