Electrical issue in manette connection

1952 XK120 FHC
Just installed a new manette and missing stator tube. Made temporary connections with the manette wires and the wires for horn and turn signals. Horn works. Right turn signal works. Nothing from the left. Have traced the wires in the car to which the manette wires connect. The feeds for the direction indicator switch go to correct lugs on the Direction Indicator Relay (DB 10). The wires for the Flasher Unit go to correct lugs on the same unit and the RF 95 Control box. I have three manettes and used them in the troubleshooting process. The one currently installed gives nothing for the left side. A new unit that came from the alleged restorer works the right side but gives nothing on the left. The original manette in the car works the right side and gives the clicking sound of the Flasher Unit when signaling but no lights on the left. If I switch the right and left feeds and signal for a left turn, the right side will flash indicating to me that the switch in the manette for the left is intact. Note, this only works for the original manette.

Any thoughts where the problem might be? Tomorrow I will switch the wires for right and left at the Direction Indicator Relay box, but that will be a bear to get to the back lug (number 8).

Sounds as if you might have a duff DB10.

Was afraid someone would say that. Switching the wires probably will yield the answer.


Try cleaning the contacts in the splitter box (DB 10) with emery cloth. Also, if you press down on the appropriate contact do the signals work? I had a persistent problem with the RH signal on my DHC, even after cleaning the contacts the signal would only last for a day or so before failing again. I found the sparing use of a little WD40 on the coils and contacts finally resolved the issue.


Will start by trying that tomorrow. Thank you. Will, also, try a little Deoxit.

There is what one might call a built in design defect in these manettes on all 120, MkV and MkVII. Where the stator tube enters the manette tube, there is a sharp edge. When you move the wheel in and out, the wiring harness rubs on that sharp edge, and eventually rubs through, and some wire will touch the tube and be grounded, such that in my case, my car would blow a fuse whenever I signaled a left turn.

It is also the case that there is contacts deep within in manette that allow the L/R indicator to work

I suggest you disconnect the manette wires, and apply power to the correct wire, and see if you have continuity through the left output wire

If you do not, you either have a defective wire, or more likely, a poor contact on the wiper inside the manette

If the latter, this will be unfortunate, as it requires the manette to be completely dismantled, down to the last screw

I have several mannetes, and two have this fault, it takes about 3 hours to dismantle and reassemble a manette, when you do it for the first time

So it does look like a problem in the left connection in the new manette.

Growler, that, also, occurred to me, but I have confirmed with an ohm meter that the switches in all three manettes work. Though not impossible, one would think that two new manettes would not have bad left turn switches. Rob, I read your previous experience with the shorts in an older thread. The wiring in this car is new as is the stator tube so that as a cause should be ruled out.

Best apply 12V and use a test light, as an ohmeter can “fool” you as a contact may pass a very small current and still measure ok, but as soon as the current is raised, it will not

Having said that, its seems likely your fault may lay elsewhere, like a bad connection or faulty component

Sounds like a fun job !

Went back this morning to check manette switches. The left turn switch on the installed one does not work. The other two manettes, an original with bad chrome and another new one, give proper signaling for the right and only clicking on the left with no light. It seems that there are two problems.

Edited to add: Took the chrome bezel, Jaguar horn button, and signaling arm off the removed manette and put it on the original. Horn and right turn work fine. Left only clicking so will attack relay tomorrow. Took the broken manette apart and found a busted part of the switch mechanism. Have glued it back with JB Weld, a form of epoxy, just for fun. May have some spare manette parts if anyone needs help.