Hi Group! This is my first post. I have a very early(810835) 140 OTS with overdrive. I am in the reassembly phase of its restoration. I am trying to figure out the electrical circuit for the overdrive. There were neither relays nor a throttle switch present when I took it apart, nor did there seem to be wiring for them or holes in the firewall where they might have been. The manual doesn't show a wiring diagram for the 140 w/OD. I'm thinking I have an early model made before the relays were introduced, the manual seems to say that by implication.
Can anyone help? I don't want to burn up a selonoid by assuming I have a simple circuit with power going through the dash switch, through the 4th gear switch then the selonoid
Thanks,
Brian

Submitted by bmurphy210@com… on Tue, 09/09/2008 - 08:09

George and Otto,
Thanks to both of you.I've ordered the single relay harness, I'll order the relay today. The MI club is having its concours this weekend, I'm hoping someone will have an early car I can look at to find the mounting site. It isn't where the two relay system is- there are no holes in the cbviously original sheet metal.
Brian

Submitted by SE98-32482CJ on Sun, 09/07/2008 - 10:39

Brian according to Jaguar Publication J. 18 dated March 1956 "Spare Parts Catalogue for 140 with Overdrive" (SIC) page 51 you need 1 relay (C.7472) or (Lucas 33157/B-SB.40) if there is no Throttle switch or you need two of them if there is is a throttle switch. On page 52 the throttle switch on the scuttle (Lucas 31402/B) or C.5605 is fitted to 811866 and sub. So you at 810835 should have the single relay system. FYI the other Subs are 800062/804523/815252/807319 and 818193. So your harness should have wiring for one relay. Hope this helps

Submitted by bmurphy210@com… on Sat, 09/06/2008 - 20:04

Hi George,
Thanks for your help. My engine # is G2355-8, and the trans is JLE27388. I assume the relay(s) would be mounted near the fuse box?
Thanks,
Brian

Submitted by SE98-32482CJ on Sat, 09/06/2008 - 18:49

Oh woops what I want to help is the engine number too! You gave the car number (vin) but please provide the engine also!

Submitted by SE98-32482CJ on Sat, 09/06/2008 - 18:46

Brian there were two variations that I kow of--one with a single relay and one with a double. The throttle switch is not necessary and Jaguar themselves wavered between using them or not but if you are intent to do it right the switch will be the difficult part to find. I can provide both wiring schematics but need the numbers off your car--in the future please remember that Tech bullitens are driven off these numbers! Let's get to work!