BlueTR3A-5EKT Posted May 24, 2021 Report Share Posted May 24, 2021 13 minutes ago, David Owen said: Has anyone fashioned a rubber pad to put between the windshield centre support and the car? It seems wrong to have metal on metal. OR am I missing something? I checked a couple of catalogues and didn't see anything. Item 15 pt no 602246 https://mossmotors.com/catalogsearch/result/?cat=&q=602246 But at £6.00 I'd fashion my own Peter W Quote Link to post Share on other sites
David Owen Posted May 24, 2021 Author Report Share Posted May 24, 2021 4 hours ago, BlueTR3A-5EKT said: Item 15 pt no 602246 https://mossmotors.com/catalogsearch/result/?cat=&q=602246 But at £6.00 I'd fashion my own Peter W I have that Peter, I meant the base of the the support. Sorry. Quote Link to post Share on other sites
Ralph Whitaker Posted May 25, 2021 Report Share Posted May 25, 2021 6 hours ago, David Owen said: I have that Peter, I meant the base of the the support. Sorry. It wouldn`t have had anything originally , but you could make a thin card gasket if you wanted. Mine is just bolted to the scuttle panel as I don`t have the mirror (I have a stick on item mounted at the top of the screen}. Ralph Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 Hmmm....I am just wondering if the gauge of the wire from the lights switch to the panel lights rheostat should be 14 or 16? I am also wondering if the rheostat drops the voltage to the dash lights even at full brightness. I was going to bypass the switch itself as I am missing one of the screws that connect the wires to each side of the rheostat. Is this OK to go ahead with? The new wiper switch I have does not fit into the alloted hole in the dash panel. It is the same switch that is labelled as the old style panel lights switch from Moss. Quote Link to post Share on other sites
Lebro Posted May 29, 2021 Report Share Posted May 29, 2021 David. The positions of the wiper switch & the panel switch / rheostat were swapped at some point during the production of the sidescreen cars. The wiper switch requires the same size hole as the older panel switch, & on older cars the panel switch was above the wiper switch. When the dimmable panel lights were introduced this required a rheostat to be fitted instead of the switch, & the rheostat is a larger item, & did not easily fit on the panel in the top position. so the positions were reversed, & the wiper switch was fitted above the panel rheostat. Regarding wire gauge for the panel lights, all together they add up to 13 Watts, which will draw approx 1 amp, so thick wire is not required for them. (Even less if you have fitted LED panel lights) Bob. Quote Link to post Share on other sites
RobH Posted May 29, 2021 Report Share Posted May 29, 2021 6 hours ago, David Owen said: I was going to bypass the switch itself as I am missing one of the screws that connect the wires to each side of the rheostat. Is this OK to go ahead with? No problem doing that. The lights are not exactly bright even when full on. Quote Link to post Share on other sites
Ralph Whitaker Posted May 29, 2021 Report Share Posted May 29, 2021 48 minutes ago, Lebro said: David. When the dimmable panel lights were introduced this required a rheostat to be fitted instead of the switch, & the rheostat is a larger item, & did not easily fit on the panel in the top position. so the positions were reversed, & the wiper switch was fitted above the panel rheostat. Bob. I think this is incorrect. The rheostat panel switch creates heat when being used dimmed, and was therefore moved to the top of the panel otherwise damage would occur to the plastic warning lights. Ralph Quote Link to post Share on other sites
RobH Posted May 29, 2021 Report Share Posted May 29, 2021 20 minutes ago, Ralph Whitaker said: The rheostat panel switch creates heat when being used dimmed, and was therefore moved to the top of the panel otherwise damage would occur to the plastic warning lights. My post 60000 TR3A has the rheostat in the middle, as Bob says. The control was actually moved down, not up. Quote Link to post Share on other sites
Lebro Posted May 29, 2021 Report Share Posted May 29, 2021 (edited) 25 minutes ago, Ralph Whitaker said: I think this is incorrect. The rheostat panel switch creates heat when being used dimmed, and was therefore moved to the top of the panel otherwise damage would occur to the plastic warning lights. Ralph Ralph / David. Yes, you were 9% right it seems ! here is an extract from Bill P's "Original Triumph TR2/3/3A" book: David, note the last paragraph, perhaps your dash was meant to have the two speed wiper switch. Bob. P.S. having just read Rob's reply (he beat me to it) it would seem to be a bit random as to where the switches went ! Edited May 29, 2021 by Lebro Quote Link to post Share on other sites
Ralph Whitaker Posted May 29, 2021 Report Share Posted May 29, 2021 1 hour ago, RobH said: My post 60000 TR3A has the rheostat in the middle, as Bob says. So does mine as it happens, but as I bought a second hand panel I just assumed I had the wrong panel. However the centre hole was shaped to stop a rotary switch turning, ie; D shaped which I assumed might have been for the 2 speed wiper switch which was also Rotary, so used this for the panel switch. 2 pics in Bill P`s book, one of a 3a on page 57 shows the panel rheostat at the top, but another of a 3b on page 52 appears to show it in the centre, so I guess either is right, but I still worry about the heat aspect and would not use mine for long turned fully dimmed. Ralph. Quote Link to post Share on other sites
Lebro Posted May 29, 2021 Report Share Posted May 29, 2021 All the holes are "D" shaped to ensure the switches are the right way up (& to stop turning) Bob. Quote Link to post Share on other sites
stuart Posted May 29, 2021 Report Share Posted May 29, 2021 19 minutes ago, Ralph Whitaker said: , but I still worry about the heat aspect and would not use mine for long turned fully dimmed. Ralph. In practice you would be very unlikely to be dimming them at all as theyre not that bright to start with also not many people do long enough night drives to want the facility. Stuart. Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 5 hours ago, RobH said: No problem doing that. The lights are not exactly bright even when full on. I was thinking that there was a possibility that the rheostat, even when full on, lowered the voltage/current to the dash lights to protect the wiring. That doesn't seem to be the case based on your responses. I will install the old wiper switch for now. Thank you all. Quote Link to post Share on other sites
Ralph Whitaker Posted May 29, 2021 Report Share Posted May 29, 2021 3 hours ago, Lebro said: All the holes are "D" shaped to ensure the switches are the right way up (& to stop turning) Bob. So they are. Is that top one smaller though? (or just far away?). Remember Father Ted? Ralph Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 42 minutes ago, Ralph Whitaker said: So they are. Is that top one smaller though? (or just far away?). Remember Father Ted? Ralph The top one is smaller. Quote Link to post Share on other sites
Lebro Posted May 29, 2021 Report Share Posted May 29, 2021 In my photo above, the top one is the right size (for a panel or 1 speed wiper switch), the one below was the same, but I made it larger so that I could fit a two position pull switch (same as the lighting one) where the 1st position turned on the wipers, & the 2nd position operated the electric screen wash. Bob. Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 (edited) Question: I have a TR4 temp gauge that is going to have to wait until next year to be replaced with proper TR3 gauge. Not knowing that at the time of dismantling I neglected to document how it was wired. There is a blue wire that comes from the thermostat housing that was feeding the signal for the gauge. I figured it out. Edited May 29, 2021 by David Owen Quote Link to post Share on other sites
Lebro Posted May 29, 2021 Report Share Posted May 29, 2021 (edited) David. Wire from the sender (in the thermostat housing) connects direct to either of the terminals on the gauge (does not matter which), other terminal on gauge goes to the stabilised voltage terminal on the instrument voltage stabiliser. The case of this must be earthed, the other terminal on the stabiliser connects to an ignition switched supply. The gauge does not need an earth to work, but will need one for it's internal lamp to work. Bob Edited May 29, 2021 by Lebro Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 1 hour ago, Lebro said: David. Wire from the sender (in the thermostat housing) connects direct to either of the terminals on the gauge (does not matter which), other terminal on gauge goes to the stabilised voltage terminal on the instrument voltage stabiliser. The case of this must be earthed, the other terminal on the stabiliser connects to an ignition switched supply. The gauge does not need an earth to work, but will need one for it's internal lamp to work. Bob Hmmm. I connected the sender to battery ground and the gauge went to full. I removed it and it went back to zero. I checked the continuity of the sender wire multiple times. I disconnected the sender and grounded it through my meter and watched the resistance drop as the engine warmed up. The voltage regulator is grounded. It is driven from the battery via the fuse box. The voltage regulator is putting out 9.97 volts. The resistance across the gauge when disconnected is 62ohms. And it still won't register. So I am obviously missing something. Quote Link to post Share on other sites
Ralph Whitaker Posted May 29, 2021 Report Share Posted May 29, 2021 39 minutes ago, David Owen said: Hmmm. I connected the sender to battery ground and the gauge went to full. I removed it and it went back to zero. I checked the continuity of the sender wire multiple times. I disconnected the sender and grounded it through my meter and watched the resistance drop as the engine warmed up. The voltage regulator is grounded. It is driven from the battery via the fuse box. The voltage regulator is putting out 9.97 volts. The resistance across the gauge when disconnected is 62ohms. And it still won't register. So I am obviously missing something. David, from what you have said it would seem everything is working as it should. You are supplying the gauge with 10v as required. You know the gauge is working because it registered when you shorted the sender to earth. You have continuity through the wires The sender is working because you have seen the resistance drop as the temperature went up. I don`t know if the 62 ohms across the gauge is correct, but I bet Bob will know. Only thing that comes to mind, is there contact between the sender and the thermostat housing, there has to be an electrical contact and something like ptfe tape on the sender could insulate it from making an electrical connection. Ralph. Quote Link to post Share on other sites
David Owen Posted May 29, 2021 Author Report Share Posted May 29, 2021 37 minutes ago, Ralph Whitaker said: David, from what you have said it would seem everything is working as it should. You are supplying the gauge with 10v as required. You know the gauge is working because it registered when you shorted the sender to earth. You have continuity through the wires The sender is working because you have seen the resistance drop as the temperature went up. I don`t know if the 62 ohms across the gauge is correct, but I bet Bob will know. Only thing that comes to mind, is there contact between the sender and the thermostat housing, there has to be an electrical contact and something like ptfe tape on the sender could insulate it from making an electrical connection. Ralph. Thanks Ralph. The sender hasn't been removed and it was functional before I started working on the car. Quote Link to post Share on other sites
Ralph Whitaker Posted May 30, 2021 Report Share Posted May 30, 2021 8 hours ago, David Owen said: Thanks Ralph. The sender hasn't been removed and it was functional before I started working on the car. Do a continuity check between the sender body and earth. Have you had the thermostat housing off, just wondering if that has continuity too. As the gasket effectively insulates it it needs a good connection under the bolt heads to earth it to the rest of the engine. Other than that I can`t understand why it would not work. Ralph Quote Link to post Share on other sites
RobH Posted May 30, 2021 Report Share Posted May 30, 2021 49 minutes ago, Ralph Whitaker said: The sender hasn't been removed and it was functional before I started working on the car. Either the sender wire is broken, the sender isn't earthed or the sender is high-resistance. I don't know where you did the earthing check David, but if you do it by removing the wire from the sender and touching it to one of the cylinder head nuts, you should get full deflection on the meter. That will show whether the wire is OK. Next touch it to the body of the sender. Again there should be full deflection. That will prove the sender is earthed. If it is, there is something wrong with the sender itself. You say you measured 62 Ohms 'across the gauge'. Sorry to be thick but do you mean the sender or the internal resistance of the meter itself? The sender should be a GRT104 Quote Link to post Share on other sites
Lebro Posted May 30, 2021 Report Share Posted May 30, 2021 Extract from a PM sent to David when I had the gauge over here for re-furb. It cleaned up nicely, & worked on my bench using fixed resistances. The temperature gauge you sent was from a TR4, is that the one you intend to use, & if so you would need the sender, voltage stabiliser, & wiring to go with it. I don't have the sender to calibrate it against, so will use the resistance settings from the book. It's a shame I did not have the sender as well. Bob. Quote Link to post Share on other sites
David Owen Posted May 30, 2021 Author Report Share Posted May 30, 2021 6 hours ago, Lebro said: Extract from a PM sent to David when I had the gauge over here for re-furb. It cleaned up nicely, & worked on my bench using fixed resistances. The temperature gauge you sent was from a TR4, is that the one you intend to use, & if so you would need the sender, voltage stabiliser, & wiring to go with it. I don't have the sender to calibrate it against, so will use the resistance settings from the book. It's a shame I did not have the sender as well. Bob. It is!!! I might just ship the car over. Quote Link to post Share on other sites
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