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[John F]

I have a 1967 Triumph radio. It is manufactured by Bendix. The model number is 7BTRX. On the left side near the rear it has a polarity switch. Does anyone know which way the switch should be set for positive ground, up or down? Any help would be greatly appreciated. I don't want to apply power to the radio to see if it works till I am sure which way to set the switch.

Thanks
John Finlayson
'62 TR4
 

[vila]

I found an original Bendix R2BT4 radio for my 1962 Triumph last year and had the same issue. 

I did a search of "Triumph Radio" on ebay every week and after a few weeks found an original Bendix R2BT4 service manual for a reasonable price.  It answered all my questions on the Positive/negative ground selector which is a bit more complicated than just a switch on the 1962 model. After figuring it out I made a small tag and attached it to the radio near the selection device on my radio.

Visit my website at: http://mysite.verizon.net/vze114b79/

Vila
1933 Chevrolet
1962 Triumph TR4
1984 BMW 633CSi

[John F]

Thanks to all. Problem solved. Polarity switch position is UP for positive ground. First thing I did was mark the case so it's never in doubt.

John Finlayson
'62 TR4