| Author | Message | ||
     Ross Rackham Experienced User Username: rosco Post Number: 23 Registered: 8-2009 |
Well apart from all the connectors popping off the aircon controls (not sure if they will ever work correctly again) I seem to have narrowed down the mystery of the non functioning passenger seat. After experimenting with providing raw 12v to the motor and 3 solenoid/gearbox things ( I think one or two of them may yet be faulty) I have found the the motor and at least one of the direction selectors work fine. In my ignorant hunt for access to the switches and master relays I have destroyed most of the centre console but discovered that the pax seat relays are only being supplied with 8 Volts as opposed to the drivers that has a nice healthy 12.5 Volts. The funny thing is that I would have expected the main 12V supply to be common for both sides. There is after all only 1 cct breaker for both seats. Has anyone come across this issue before? Here is a pic of the current carnage for the amusement of all and sundry. Cheers Ross  (Message edited by rosco on 16 August 2009) | ||
| Ross Rackham Experienced User Username: rosco Post Number: 24 Registered: 8-2009 |
Slight correction, the power comes through 2x fuses on the inboard side of the fuse box. Not mentioned on the pull out cct diag. If I am lucky it may be corrosion causing a high resistance at either the fuse or where the wire connects to the fuse box. Enough for today, I need a large drink! | ||
| Brian Crump Experienced User Username: brian_crump Post Number: 48 Registered: 2-2007 |
Good luck Ross. The last time I did something like that I had to resort to a Single Malt to restore my sensibilities. I can't offer any advice but I can sympathise. Have you bought a copy of J. Waples' The Shadow Owners' Companion? If you are ever in Sydney drop past and borrow mine. It is useful when adventuring into the nether regions of a Shadow. Regards, Brian Crump (Message edited by brian_crump on 16 August 2009) | ||
| Ross Rackham Experienced User Username: rosco Post Number: 25 Registered: 8-2009 |
No worries Brian and thanks for the offer. It's not as bad as it looks, I've got most of it figured out but just have to find that bloody voltage drop. That and possibly attempt to service the 3 gear servos. The neat thing about older cars like this and the W123 series Mercs is that many things that are now sealed units and have to be replaced can actually be stripped down and serviced. At the very worst I'll run a 12v patch and fuse it in the console or under the seat. "NOW I KNOW" I could have just popped off the console side covers. Not to worry. There is only one wire that popped off that I'm not sure where to plug in but I'm hoping a clean spade connector with fresh marks may help locate it. Either way it's good practice for the up comming CD instal. | ||
| Ross Rackham Experienced User Username: rosco Post Number: 26 Registered: 8-2009 |
OK, the problem is officially solved AND I nominate myself to be entered into the “Retard Hall of Fame”, with honours. The problem, a high resistance fuse. That's right a bloody FUSE. I began by ingesting a reasonable quantity of brain lube, thus fortified I thought I would check both sides of the fuses to confirm 12V before pulling off the back of the fuse box. The supply side of each fuse had a solid 12.5V. So I'm now suspecting the wire between the fuse box and relay set in the console. Just to be sure I pop out both fuses and clean the contacts while I'm at it. While there out I also check both fuses with my meter, both good. Just on a hunch I try both fuses in the suspect circuit. Bugger me! One gives 12.5 at the relay AND the seat functions! The other 9V and no operation. The bastard fuse was going high resistance UNDER LOAD. Go figure. All, please learn from this, swap out the simple things first. If I had just swapped the fuses around in the first place I would have a drivable car. Keep it simple! So tomorrow, some what red faced, the reassembly will begin. Cheers Ross | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 380 Registered: 6-2006 |
Ross - but without that fuse you would never have got round to stripping everything to see how it works. ;) R-R glass fuses (ulgin) can be a real pain with their soldered ends. They get dry joints and although they look fine, give all sort of problems. At least next time it will be easier! Good luck. Have the drink and enjoy. | ||
| John Budden Experienced User Username: johnb Post Number: 22 Registered: 4-2006 |
Ross, Thanks from all of us for sharing a lesson that we keep forgetting. It is my experience also that conections in one form or another cause more problems than devices. | ||
| Ross Rackham Experienced User Username: rosco Post Number: 28 Registered: 8-2009 |
100% correct John, the standard tech rule of thumb is "Every connector or join is a fault waiting to happen". Thats why I'm taking the time to solder all the new crimp terminals I'm fitting and where I can get away with it, no connectors at all, just solder and heat shrink. I did tell the guys that are going to fit the CD head and amps that if I saw one scotch lock connector I would be back with a batt. I did notice that all the electrical tape in the workshop was Nitto, which is always a good sign. (Message edited by rosco on 18 August 2009) |
