Hello,

To use the later O/D relay with the self canceling feature from a later Volvo you need to use a momentary switch as a O/D triggering switch, preferably a switch that can handle positive voltage, but that is not manditory.

There are several different relays that are used on Volvos of several colors, but I prefer the early blue one for 1981-1984 Volvos as it has a standard connector pattern that I can easily get a pigtail that fits.

On pre-1970 1800, you can use the ground signal from the stock O/D column switch by using a stardard relay to trigger the blue O/D relay.

On all 122 and all 544, you can use the ground signal from the headlight flasher switch from the turn signal switch, to trigger a relay to run the O/D relay IF you are not using it to already trigger the headlight flasher.

Or you can buy a shifter knob with a switch already in it from a performance catalog or shop and this can be done on all the 1800e/es, 122, 544 and 140/160 or you can add a momentary switch on the dash or steering column cowl.

My favorite conversion is to use a 1974 or 1975 shift cover(1975 won't fit M400/M410). This allows the use of a chrome upper shifter handle, knob and O/D switch from any 1981 and later Volvo that used a "J" style O/D.

You have to drill a hole in chrome shifter handle that is 90° to the factory hole to properly mount the later handle onto the shiter stub shaft from the 1974/75 shift cover, but it uses the same size retaining pin.

The 74 shift covers can be used on all M41 and M410 transmissions.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90501