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MG TD TF 1500 - Wiring in a radio to the acc switch

Looking at the wiring diagram for my 51TD, I'm not sure which connection I should wire to on the ignition/acc switch when adding a switch for an accessory item (power for a small sound system). The terminals are labelled A, IG, H and T on the wiring diagram. I'm guessing that I should connect the power wire to A? I want it to come on only when the key is in the ignition and has been turned.
Oddly, could not find this information searching the archives for "wiring accessory switch" and a bunch of other search terms.
Thanks for the help and apologies for posting a very obvious (and therefore much-answered) question...
Geoffrey M Baker

Geoff, check the wiring diagram. You'll see that white wires are the ones for power controlled by the switch. A common point is terminal A3 on the fuse block. The terminal on the switch is the 'IG' one. Bud
Bud Krueger

Geoff,

Good time to put in a fuse block. The wood strip up under the dash is a good mount point with a short reach to the switch. Some stereos require both switched and unswitched power - unswitched to keep the memory. Wiring the block means you only have to mess with the switch once (hopefully!).

Jim
J Barry

In reading this and your other thread on your installation, no one has recommended the use of a relay between the fuse box and the ignition switch. With all the assumed power consumption of your components, I think it could eventually cause problems with the switch. Small relays are low in cost (most come from China anyway) and well worth considering. I used one just to connect my radio and heater motor.
Jim Merz

Jim M, that's a good idea and one I plan to implement, along with a decent fusebox. I want a relay for the headlights, brake switch and stereo (I already have on installed for my security lock). I'm thinking of mounting it all in the toolbox, but haven't decided.
As I mentioned in the other thread, I wired it in today and it worked perfectly. A nice chirp as the Bluetooth turned on and found my phone... then music!
J Barry, yes, I'm planning on it. My amp does require both switched and unswitched power, not for memory but for "soft on" and soft off" settings to avoid overloads.
Geoffrey M Baker

And by the way, thanks for all the good advice... and have a very Merry Christmas all!
Geoffrey M Baker

This thread was discussed between 22/12/2014 and 23/12/2014

MG TD TF 1500 index

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