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Re: Overdrive electric circuits

Posted: Mon Mar 13, 2023 12:11 pm
by JCS
My car 3.4 ltr chassis IB 4722 DN was passed off production 6th August 1965. It has full synchromesh gearbox and overdrive, with an inline fuse protecting the overdrive circuit.

The original in line harness fuse for the overdrive is located on the left side of the steering column, under the dash, just about above the clutch pedal. Often the continuity of the fuse arrangement is broken by the end contacts of the in line fuse holder and not just a burnt fuse. I use the term burnt fuse rather than blown fuse, as these fuses tend to burn out with heat.

Re: Overdrive electric circuits

Posted: Tue Mar 14, 2023 8:12 pm
by Glyn Ruck
Warning ~ Fuse values


Remember that Lucas fuse values of 35 & 50 amp etc are old British 1 second blow standard.

Fuses you buy today unless you order specially are American Carry Current rating.

In modern fuse values you should select a fuse of approx half the value of the Lucas rating shown in Jaguar Manuals.

e.g. Lucas Horn fuse = 50 Amps. In modern US rated glass fuses you should fit 25 to 30 amp.

Failure to do this could cause a fire in our car's wiring in case of a short.