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Electrical Puzzle

Posted: 29 Oct 2007 03:25
by Rich in Vancouver
Big surprise eh!
Anyway, I bought my 1975 TR7 3 months ago, and with the darker autumn mornings I found that I have no dash lights. I explored a bit and founf the panel light rheostat was disconnected and the console lights were bundled behind the console. This wasn't too much of a surprise as the electrical system has been pretty much savaged by PO's. I reconnected the rheostat and put the sockets in the appropriate places and discovered that the dash lights work, but when I turn them on the high beam light also comes on and all 4 turn signals come on but do not flash. This is not good!
Any ideas as to the cause of this? I spent the afternoon tracing circuits and can't find anywhere that these circuits or circuits related to them) come into contact...except for the headlight switch.
If anyone has any good troubleshooting tips please let me know as I have just about exhausted my patience on this one!

Cheers,
Richard
BTW: All running lights, headlights, brake lights, turn signals, etc work well if the dash lights are off.

1975 TR7 ACL764U
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Posted: 29 Oct 2007 06:10
by bottomtop
How very odd.

My understanding is that those flimsy plastic circuit things in fact changed during the production run - perhaps it was replaced with the wrong one by a past owner? Otherwise it is almost as if there is a trip somewhere inside the junnction where the loom plugs onto the board.

Posted: 29 Oct 2007 12:36
by Rich in Vancouver
Good suggestion BT.
I will have to take a look at the board.
It wouldn't surprise me if it has been swapped as the PO's did some odd things to the electrical system.

Richard


1975 TR7 ACL764U
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Posted: 29 Oct 2007 17:35
by jclay (RIP 2018)
They also come together at the emergency flashers!

Have fun, drive fast & safe, be kewl,

jclay

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Posted: 29 Oct 2007 18:09
by bmcecosse
Do the actual external lights come on - or is it just the warning lights on the dash that are illuminated ?

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Posted: 30 Oct 2007 00:27
by Rich in Vancouver
It seems it's just the warning lights that come on along with the high beam warning.
I spent a bit more time under the dash today and found that the two multi-plugs that attach to the circuit board are in securely. I did notice that there are some wires connected with standard push-on spade connectors at the bottom of the board. Could these be the problem? There is one LG/W wire there that I can't find on my wiring diagram, and I also have a G/B wire hanging loose. I think that this wire is for the fuel guage but am not sure if I should plug it into the remaining blade at the bottom of the circuit board. Oh yeah, The dash lights on the circuit board aren't lighting up but the lights on the console are.[:(]
I'm off to read the manual again.

Cheers,
Richard

1975 TR7 ACL764U
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