| Author | Message | ||
     Randy Roberson Grand Master Username: wascator Post Number: 437 Registered: 5-2009 |
She finds Herself in need of replacements. What do these three switches accomplish? I understand one of them turns on the electric assist fan at 102 C coolant temp. Are there any lest costly alternative sources? I see that these were used on Jaguars, and maybe other cars: the price for the Jaguar switch is 35 pounds. I also see one conversion kit which mounts a threaded device in place of the original otter switch. If the temperature setpoint is known, one might use a similar device for all three, maybe? At $300 each I would be open to it. | ||
| Robert Noel Reddington Prolific User Username: bob_uk Post Number: 119 Registered: 5-2015 |
These otter switches were used on many brit cars such as Jag and Rover. 102c is quite hot and I know that some otters work at a lower temp. This means that otter switches aren't all the same. For Jag bits David Manners. They will know the temperature of the Jag ones. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1388 Registered: 6-2009 |
Randy and Bob, I am getting quite confused here just because I can't envision what switches are being talked about. I thought the things that control when the auxiliary fan comes on, the temperature gauge, etc, were the senders that are shown as screwing in to the thermostat housing here:  If not, can you point me to the switches you're referring to? Most of the Otter switches that I can pull up in my mind are in small plastic enclosures, usually square, and have the word "Otter" emblazoned on them. Brian | ||
| Randy Roberson Grand Master Username: wascator Post Number: 438 Registered: 5-2009 |
The otter switched are I believe on an earlier model but they (3) are mounted two on the thermostat cover and one below the thermostat. On my Car they mount with three screws in a triangle configuration with a gasket. I understand the one below the thermostat turns the auxiliary fan on and off; not certain what the other two control yet. In any case mine are toast. | ||
| Robert Noel Reddington Prolific User Username: bob_uk Post Number: 120 Registered: 5-2015 |
The otter switches I am familiar with are held in with three screws and a triangular plate. On the drawing there's 6 sensor looking things. UE 40361 is probably the temperature gauge sensor. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 439 Registered: 5-2009 |
Brian's drawing is the arrangement for fuel-injected engines. My car is an earlier model, as this drawing. As Robert offered, the triangle mounted switches are the Otter switches.  | ||
| Robert Noel Reddington Prolific User Username: bob_uk Post Number: 121 Registered: 5-2015 |
Those are otter switches. I would have thought that a fan switch would be above the thermostat. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 440 Registered: 5-2009 |
Gents, I found that jaguars including the E-Type used an Otter switch to turn the fans on: setpoint 185F. I attach a photo of a modern substitute offered for abut $40 US. I say, perhaps we can beat $300 if we know the setpoint of all three switches.  | ||
| Randy Roberson Grand Master Username: wascator Post Number: 441 Registered: 5-2009 |
Robert is correct I think: best I can tell from studying the Manual and vendor lists: the switch on the right side of the thermostat elbow (outlet) turns the auxiliary fan on. Part number RH 3074. There seems to be a reasonably priced conversion kit offered to replace this with a modern, readily available switch. The left switch on the thermostat outlet elbow is the EGR primary valve lockout switch: setpoints opens at 57F or 14C rising; closes at 54F or 12C falling. the switch below the thermostat is the EGR valve secondary lockout switch: setpoints opens at 111F or 44C rising; closes at 108F or 42C falling. Note: I think. Subject to revision. Your mileage may vary... To verify one can jump across the terminals of the harness plug and tell which of the solenoids moves. Of course, the fan will come on, assuming one jumps the correct plug and the fan is otherwise operational. | ||
| Robert Noel Reddington Prolific User Username: bob_uk Post Number: 123 Registered: 5-2015 |
This is what I mean by emission control junk. 2 extra switches and relays and wiring. The 40 dollar switch looks fine. The egr switches. Does the switch point temperatures need to be accurate. I am glad my car is UK spec and doesn't have extra switches. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1391 Registered: 6-2009 |
Randy, That modern substitute looks like a random (and by that I don't mean doesn't function correctly) temperature switch simply fitted to the triangular plate, which would have been tapped to match the threads on the switch. If you are successful in determining the actual set points for all the switches and can document their functional equivalents available at virtually any auto parts store, you'll be doing the RR/Bentley community a great service. I believe that the switches on my cars are still functioning. If there's a test that's reasonably easy to do with a pot of water, a thermometer, and a multimeter to determine what needs to be determined I will be glad to assist if that procedure can be precisely described. In the long run, the only way we're going to keep these cars going is document the functional specs on these switches and then seeing if some far more common marque uses a switch with exactly, or very nearly exactly, the same specs. Brian | ||
| Randy Roberson Grand Master Username: wascator Post Number: 442 Registered: 5-2009 |
That''s exactly what it is. It is offered by "CoolCat Express" which one might discern is Jaguar-oriented. Looking at the drawing you posted, those switches probably do the same thing and look like they would be adaptable to the Otter mounting. The Factory manual ought to have the setpoints listed in the test procedure. I need to study the function of the EGR control system more thoroughly; seems though that, as one doesn't want EGR when the engine is cold nor when it is idling, these simply prevent the EGR from working until the engine is warmed up; perhaps there are two so that the EGR can be activated partially before warmup is complete, or something like this. No doubt there is a reason. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1383 Registered: 6-2006 |
The 44 degree operates the air con fan cut out circuit as well. Heater / Blower Fans will not operate until water temp is higher than 44 degrees ( unless defrost is selected). | ||
| Robert Noel Reddington Prolific User Username: bob_uk Post Number: 124 Registered: 5-2015 |
As Brian said its screwed into a triangular plate. Which could easily be made. And any switch screwed in. This opens up the choice somewhat. The elbow would look nice painted black to contrast the shinny switches. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 443 Registered: 5-2009 |
I confirm on my Car the rh switch on the thermostat outlet housing operates the auxiliary fan: I jumpered the harness and it came to life. Also, the other switch on the outlet housing operated the rear most of the three solenoids mounted to the left of the B-bank carb. The harness to the bottom switch did nothing that I could tell, but as it is the secondary switch, perhaps it acts once the primary switch opens and activates its solenoid. I thing CoolCats would probably sell me some of the threaded triangular adaptor plates and I could find myown appropriate switches. There is a similar adapted switch at IntroCar and FS for the fan on-off for circa $80 US. The switch below the thermostat is the one that is $300. Someone who has access to a Factory manual for Brian's vintage Car (i.e. fuel injected) might review the test procedure for the EGR switches and confirm their set points. They are cheaper than the triangle mount switches and will likely fit the adaptor plates because the switches are threaded for the fuel injected Cars. they even seem to have the same harness connector as the earlier switches (i.e. my Car). | ||
| Randy Roberson Grand Master Username: wascator Post Number: 444 Registered: 5-2009 |
This from the Factory manual for the 1976 North American Cars: "To improve starting and driveaway quality at low temperatures solenoid valves activated by lock-out switches (see Fig. 15), interrupt the vacuum signals to both exhaust gas recirculation valves, ensuring that they remain in the closed position, until predetermined coolant temperatures are reached. The secondary valve cuts in at a higher coolant temperature than the primary valve" | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1392 Registered: 6-2009 |
Randy, None of my cars are fuel injected. I have a 1978 Shadow II and a 1979 Silver Wraith II. I just happened to pick the wrong page from the spare parts manual because I hadn't paid close enough attention to the chassis number range shown on that page. Brian | ||
| Randy Roberson Grand Master Username: wascator Post Number: 445 Registered: 5-2009 |
I can't find a Factory manual late enough to look at the test procedure for the switches as on the drawing you originally posted. These are threaded and may cost less if the function is the same. | ||
| David Lacey Experienced User Username: dlacey Post Number: 43 Registered: 11-2010 |
All, When looking for low cost replacements of the Otter switch be careful to avoid it's close relative the Beaver Switch as this will block your waterways.....} | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3220 Registered: 4-2003 |
The Kangaroo switch is by far the best because it bounces back again and again. There are plenty of spares hopping around out there too. |
