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Triumph TR7 Wiring problems

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dartt123
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Triumph TR7 Wiring problems

Postby dartt123 » 15 Feb 2011 23:21

We recently purchased a 1980 Trimuph TR7and were told it needed a valve job. The seller said it would turn over, but not start. When we looked at it, he claimed the battery was run down, so we bought it taking his word for it. After I got to looking it over I discovered the wiring had been hacked into and pieced together. I came to the conclusion that maybe the starter was fried, so we bought a new one and I have installed and uninstalled it at least 8 times thinking I had done something wrong. It doesn't even attempt to turn over when you turn the key. Then I tore the ignition switch apart thinking it must have an issue. Well it DOES NOW! Anyways, I have picked up a new universal ignition switch, new battery, new battery line, ran a new fuse panel and a new line to the starter and new line from fuse box to ignition and then to the solenoid. I bought a new grounding strip and installed it to the firewall and the transmission, but I still get no results when I try to turn the engine over. I show power getting to the ignition, to the starter, and even took the new starter in to the auto parts store and had it tested to confirm it's actually good. It worked perfectly when they hooked it up on the test equipment. Does anyone have any suggestions or helpful information? This is really kicking my butt and I hate giving up!

dartt123

jclay (RIP 2018)
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Postby jclay (RIP 2018) » 15 Feb 2011 23:37

Wow! Sounds like a mess! If you had not changed the wiring, fuse box and switch, I would have some idea where to start!

When you say that nothing happens, do you mean that the starter doesn't turn, or that there relay does not click? Are you using any of the original wiring?

Clay

[url="http://web.mac.com/jclaythompson/Site/Welcome.html"]My Triumph Site[/url], [url="http://web.me.com/jclaythompson/Technical"]Technical Stuff[/url], [url="https://docs.google.com/?hl=en&tab=wo&authuser=0&pli=1#all"]Download Page[/url]

dartt123
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Postby dartt123 » 16 Feb 2011 00:56

The starter doesn't turn and the relay doesn't click. I haven't eliminated the original wiring, I just added the new so far and bypassed the existing.

dartt123

FI Spyder
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Postby FI Spyder » 16 Feb 2011 01:19

I repeat Clay's comment about a mess. When you turn the ignition on it should activate the starter relay (attached to the side of fuse panel. The relay should activate the solenoid. As we know the starter is good we should hear the relay click at least. If it doesn't you would want to check to see if you have power going to it to activate it. Select the correct wiring diagram from the OEM manual on jclay's website to find the wires and their colours. This assumes not too much has been fiddled with on the stock wiring.


TR7 Spider - 1978 Spitfire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT
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jclay (RIP 2018)
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Postby jclay (RIP 2018) » 16 Feb 2011 02:36

Check under the car at the transmission. You are looking for a connector that has a loop in the end. If it is not connected to the wire running behind the engine, over the bellhousing, then there will be no power to the relay.

This should be a White/Red wire. When an automatic transmission is installed there would be a Safety Switch installed. On the standard transmission models, they just installed a loop of wire.

So, if you have power to and from the switch, but no power to the blue relay in the glove box, then that loop is your problem.

Clay

[url="http://web.mac.com/jclaythompson/Site/Welcome.html"]My Triumph Site[/url], [url="http://web.me.com/jclaythompson/Technical"]Technical Stuff[/url], [url="https://docs.google.com/?hl=en&tab=wo&authuser=0&pli=1#all"]Download Page[/url]

saabfast
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Postby saabfast » 16 Feb 2011 19:38

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by dartt123</i>

Anyways, I have picked up a new universal ignition switch, new battery, new battery line, ran a new fuse panel and a new line to the starter and new line from fuse box to ignition and then to the solenoid. <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Does this mean you have rewired totally and bypassed the starter relay? There are a number of other items switched by the start relay but if you have wired directly from the ignition switch to the starter solenoid, and there is power from the battery to the large connection the solenoid should pull in and turn the engine over even if nothing else happens.
If you short across the large terminal from the battery to the terminal where the connector goes into the starter motor (ie with a screwdriver) the engine should turn over. This shows the motor power is connected and OK. Also check the small terminal from the relay to the solenoid. They live in a rough area and are often corroded inside the cable to spade connection and do not pull in the solenoid.
If you did wire through the starter relay (which you cannot hear click in) it is possible the relay has failed (not uncommon). I initially had to start mine (after growing tired of using the screwdriver on the starter terminals) by removing the top of the starter relay and making the contact work with my fingers. Note when replacing the relay it is quite a standard one. In the UK I could only get one from the Triumph suppliers.
If you did wire through the starter relay

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC
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trekcarbonboy
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Postby trekcarbonboy » 16 Feb 2011 21:03

Is the grounding strap connected to the engine? Check the block-to-transmission bolts on the left side of the engine. Ground wire should be connected there somewhere.
And that my friends would be the extent of my electrical trouble shooting knowledge! [:I][:D]

Craig
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Jez
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Postby Jez » 18 Feb 2011 22:12

May I suggest getting a copy of the Haynes TR7 manual as it has all the wiring diagrams, with all the colour coding for each wire for each region of the world (we, Australia, use the US wiring schematic)
At first it may seem a bit daunting, but it is a schematic so you just trace with your finger or pen along the circuits you are querying. I have done this and saved many a head scratch. I bought a manual for the TR7 and one for the Rover SD1 for the engine transplant. This makes splicing in a lot easier.
Good luck!
Jez

11/80 Inca Yellow TR7

birminghamtr7
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Postby birminghamtr7 » 18 Feb 2011 22:22

check you have a good earth to the engine block put extra one on anyway then try, you could also rig up a wire with a spade direct to the starter motor solenoid then dab on battery just to prove its functioning

if you factor in the earth's rotation, we are all speeding

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Morley Faulkner
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Postby Morley Faulkner » 19 Feb 2011 01:26

Hi, Have you tried turning engine over by hand. Its not siezed-up is it !!

slider
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Postby slider » 19 Feb 2011 09:31

are you sure that an immobilser has not been fitted(and thats why the wireing has been butchered ?)[:(][:D] just a thought!

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