Hello George,

On some Smiths tachometers, the wire from the points goes to the tachometer 1st and INTO the tachometer before going on to the negative terminal on the coil and this includes the original optional Smiths tachometers for the pre-1973 140/160 series and the stock 1800e/es.

So if the tachometer has an internal short, it can keep the points signal from reaching the coil and thus cause a non runnning condition.

On the 1800e/es, the tachometer connections at the back of the tachometer are bullet style connecters and if the tachometer is bad, you can easily bypass it at the tachometer by plugging the 2 wires together as they are a male and female bullet connector.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90501