Series II XJC Window Issue - Passenger Side Not Operating

XJ
1

Hi all - I have a 1976 XJC whose passenger window was operating very slowly, then stopped operating altogether. The other windows operate with no major issues. Would this be the switch itself, or the window and its motor? I understand that power flows from the driver’s side through the other windows in a type of relay, but the back windows operate, so would that negate the effects of the passenger side window not operating?

Thanks for your advice!

2

I would expect to find that the motor is either seized or burnt out, time to investigate by taking the door card off. The sniff test will indicate if the motor is burnt.

3

given it slowed before it stopped, it might just need some lubrication?

silicon based solvent might be worth trying before you pull things apart?

4

Thanks both - I’m thinking motor most likely as I’m understanding that if the switch were faulty, there wouldn’t be power to the rear windows and they wouldn’t work? Would that be the logic behind the way the switches are set up? I ordered a new motor (hard to find!) and switches (even harder!) just in case and don’t mind holding onto them in case they’re not the culprit as these things have a way of failing over time anyway.

5

I am told that the window motors are GM units that are very similar to late 70’s Camaro. These motors are available new for about $70.

6

**
Not necessarily, Scooter…

Basically; the set-up is a ‘series’ connection - allowing only one window to operate at a time. Ie, with one switch thrown; there is no power to the other switches/motors. If a switch makes no contact to its motor when thrown, the motor won’t run - but it may still still make the contact to the other switches when released…

A thermal fuse is used to protect the motors; a stalled motor would trip the fuse, cutting power - and the fuse would reset after some time, presumably preventing motor burn-out.

So it’s good odds that the motor is OK, and the switch is faulty, but the slowing of a motor strongly indicates that lubrication of the lift mechanisms is urgently needed as others suggest - when was the last time…?

That should really be the first step; as the motor slows/stalls very high current is drawn through the switch - which need little excuse to burn and lose connectivity. Cleaning up switches has been done successfully, a very fiddly job, as an alternative to replacement - but without well lubed lifts it’s very likely the problem will spread. Of course, if a motor is really burnt out, proven by testing; replacement is the single option…

Frank
xj6 85 Sov Europe (UK/NZ)

7

I am of the same view. Check the mechanism and the felt tracks (realise it’s a coupe). I fitted new felts to my XJ6 and it took some time to bed them in - motors ran slowly. The same problem presents if the mech is binding or the window has become skewed. Per above absent smoke and smell the motor windings should be sound. Really, the passenger window should be in better shape than the driver’s.
I would work through the connectors to ensure good continuity and see how it operates absent the switch. I recall my switches getting hot before I serviced them. FWIW.