| Author | Message | ||
     Tim Millard Unregistered guest Posted From: 61.68.157.73 |
I recently purchased a lovely 78 SS, which has been very well maintained but came supplied with a mysterious electrical issue - the AC fans and compressor remain on with the ignition off. The servos respond to the respective dials, the AC blows ice cold, and the fan speed varies as it should - it just remains on with he ignition off. With the brown/blue wire, or the brown/pink wire disconnected at the fan/comp relay, the system switches off. As suggested in the manual, applying 12V to the brown/pink wire at the fan relay (fuse box) switches the system off. The system runs whether or not the ignition fuse is fitted. The car has a reduction starter fitted, and the brown/blue wire is attached to this in such a way that it is always live (ie with the battery cable). With the brown/blue wire disconnected at the starter, the system will not run at all. The oil pressure light works as it should (ie, not dimly lit when running, which theoretically rules out the diode). If brown/pink being live switches the system off, does this mean that even with the ignition off, the function switch is supposed to be live? It makes no sense to me that the brown/blue wire is always live at the starter. If it is to cut fans at start up, should it not be attached with the short thick wire between the relay and the motor itself (ie when cranking)? I have looked at the wiring diagrams, which show only that the wire goes to the starter, but not to where. I am stumped - any ideas would be much appreciated! (Message approved by david_gore) | ||
| Tim Millard Unregistered guest Posted From: 61.68.157.73 |
Another clue - the fuel door works whether or not the car is running (Message approved by david_gore) | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 209 Registered: 7-2012 |
Tim, You are correct! There is a relay(fan & comp. relay) that serves both. It's really hard to trace on screen, but over next couple days I have access to manual and will look further/find out where fan 7 comp. relay lives. | ||
| richard george yeaman Grand Master Username: richyrich Post Number: 838 Registered: 4-2012 |
Tim I don't know very much about car electrics but if the car, was mine I would look at the ignition switch as a starting point, perhaps someone with more knowledge could suggest some other areas to investigate. Good luck. Richard. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 1533 Registered: 9-2004 |
From the way I see it there are two relays that could be one or the other. The fan-compressor relay is under the bonnet the first one of three attached to blower motor ducting.  The second is inside the car n/s dash.  My SS2 and SS1 both have filler doors that work with ignition on and off. | ||
| Tim Millard Unregistered guest Posted From: 58.170.113.245 |
Hello gentlemen, thanks for the assistance. I Iocated the relays and tested the one under the dash as per the manual - it was fine. I did wonder about the ignition switch. I need to clarify the wire to the starter though - it was fitted to the battery cable post, which makes no sense to me. The manual says the fan/comp relay is earthed through the starter. But I don't understand how this can be so. (Message approved by david_gore) | ||
| Jake Jenkins Unregistered guest Posted From: 86.158.158.242 |
I would strongly suspect the brown/blue wire is on the wrong terminal at the starter motor solenoid, especially as it has had another starter motor fitted. This is not an uncommon mistake to have been made. (Message approved by david_gore) | ||
| Tim Millard Unregistered guest Posted From: 58.170.113.245 |
Hi Jake, my thoughts exactly. Do you know where the brown/blue wire is supposed to go? Manuals say starter but not where ! (Message approved by david_gore) | ||
| Jake Jenkins Unregistered guest Posted From: 86.170.214.97 |
Hello Tim. The brown/blue wire connects to the starter solenoid that only becomes live during cranking, NOT the permanently live from the battery. Just swap the wire on the solenoid connections. This wire becomes live during cranking and as soon as cranking stops, it finds earth through the starter. This should cure all the problems relating to fans and fuel flap. I do not know the layout of a reduction starter but I assume it is the same as the original. Jake. (Message approved by david_gore) | ||
| Tim Millard Unregistered guest Posted From: 61.68.182.245 |
Hi Jake, Thank you. Sadly, from what I can see there is only one "minor" connection on the gear reduction starter (the trigger wire). Should I just earth the brown/blue wire and forget about the cranking interlock? (Message approved by david_gore) | ||
| Jake Jenkins Unregistered guest Posted From: 86.170.215.205 |
Hello Tim. If there is not another solenoid terminal beside the live battery feed on a reduction starter motor, I am stumped. As I said, I have no experience of this type of starter but others have fitted them so it must be possible to connect the brown/blue wire somewhere. I will see if I can find a picture of said starter and if I can see where the wire goes, I will post again. I get a feeling things will not work correctly if you just earth the wire as it has a 12v feed when cranking. Jake. (Message approved by david_gore) | ||
| Jake Jenkins Unregistered guest Posted From: 86.170.215.205 |
Hello Tim. After looking at a picture of the reduction starter, I suspect the wire goes onto the terminal on the starter itself. It looks to be under the rubber cover on the starter motor, the terminal that becomes live on cranking, from the solenoid. I could not find a good picture but the solenoid has to have two wires, feed in, power out. The wire needs to be on the power out side. Jake. (Message approved by david_gore) | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1869 Registered: 6-2006 |
Hi Tim, yes move it over to the big wire terminal that is live when cranking. The idea of the crank interlock is to stop the A/C system using lots of battery power and making starting slow and difficult. However, the new starter will use almost no power compared to the old Lucas ones so the engine will turn over much faster and still have plenty of power for a spark anyway. So better and just as easy for you to connect it correctly. Not the end of the world if you just earth it. | ||
| Tim Millard Unregistered guest Posted From: 61.68.182.245 |
Hi Jake and Paul, I thought about that terminal, but presumed that if an earth makes it run, it wouldn't get it from the live-on-crank wire. Yesterday I had another look and thought as an experiment I'd try earthing the relay and see what happens. Fans/comp switch on and off as they should, and they switch off during cranking anyway. Win! I haven't tried the flap yet, though. Thanks for your help. Now for poorly parking wipers. (Message approved by david_gore) |
