zulublue Posted October 30, 2007 Share Posted October 30, 2007 Hi All, I have just fitted a X-Eng thermostat, well nearly as the daylight left me anyhow I started her up a tried to get the engine up to temp. The engine is a 200TDi in a defender. I want the system to work normally when switched on and when in water I can cut power to the fan or thermostat. I got it as virtually hot as it goes there is a little more to go but as its a Disco block I figured the temp sender may be different. Anyway no fan cut in, I have put the wire on the low sensor side of the thermostat I know there is power to the thermostat, and the switch is working. So have I wired it up wrongly or is it not hot enough, the reason I mention the temperature is that the top hose is nice and hot, you can just bare it to the touch, the pipe from the therm to the water pump is hot, but the bottom hose is very cool, I understand that this is after the rad, but I would expect a slight but of warmth from it. And yes the gauge is in the bottom hose. This is how I have wired it up, and your correct I do need a fuse. Mark. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 30, 2007 Share Posted October 30, 2007 Depending on your thermostat it may not get hot enough without a thrashing, TDi's just don't get hot sitting about. Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 30, 2007 Share Posted October 30, 2007 Yes to a fuse.... Always use a fuse.... Did you take the thermostatic switch out of the circuit and short across the two connectors to see if the fan runs ? Neil Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 30, 2007 Author Share Posted October 30, 2007 Hi Neil, yes I remove the live from the thermostat and put it directly to the fan and it worked fine. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 30, 2007 Share Posted October 30, 2007 Your wiring diagram looks a little strange. I would use the 'stat and override to feed the relay, rather than having the 'stat and relay in parallel. I reckon you'll struggle to get the 'stat to switch in, you'll need to have the engine running at high revs for quite a while to get it hot enough. My stat only switches when the engine has been loaded (hills/motorway) and then air flow is reduced, like stopping at services, traffic lights etc. Also, it looks like you're using the high range switch, not the low range. Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 30, 2007 Share Posted October 30, 2007 Then I'd go with what Ian (Fridge) is suggesting... Take it for a run and get it up to temperature on the guage and through the engine.... Sit on tickover and see if it comes to life.... If that fails, whip the thermostat out and pop it in a pan of water (suspended), boil it up and measure the ressstance across the switch.. Check it's acually operating as expected... Quote Link to comment Share on other sites More sharing options...
Ex Member Posted October 30, 2007 Share Posted October 30, 2007 The bottom hose needs to be hot for the switch to turn the fan on. You said it is cold....... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 30, 2007 Share Posted October 30, 2007 Ian (Fridge) Who he? I'm John I have to say I did stick my X-switch in boiling water to confirm operation too. Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 30, 2007 Author Share Posted October 30, 2007 I will give it a boiling water bath tomorrow after a good run and test first Can you see an reason why there is such a difference between the top hose been hot and the bottom been cold? Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 30, 2007 Share Posted October 30, 2007 I would guess it is down to a reasonably low water flow rate (assuming the engine was at tickover) and a reasonably efficient radiator doing it's job. Pete. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted October 30, 2007 Share Posted October 30, 2007 I will give it a boiling water bath tomorrow after a good run and test firstCan you see an reason why there is such a difference between the top hose been hot and the bottom been cold? Because the radiator is removing all of the heat.... If it is doing that, then the fan does not need to come on. A fan is only needed when the radiator is discharging hot water. If the engine was overheating, you have a serious problem somewhere else. Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 30, 2007 Author Share Posted October 30, 2007 If the engine was overheating, you have a serious problem somewhere else. That's what I am now worried about I had the engine running for about 10 minutes, I then took it for a blast only about a mile, the temp Gauge was 4mm under the red line (this has changed since the disco block went in, about normal) I have measured the temp with one of those laser lights (don't know how good they are) and it was about 70 degrees and that was after a good run. perhaps it is working fine. I did remove the top of the boost bottle after the 1 mile run there was a bit of pressure, but nothing to make the water spurt out, and the water in the bottle was cold (very) don't know if that points towards anything, I know my V8 was totally different. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 30, 2007 Share Posted October 30, 2007 Stuck thermostat will give reduced flow, hot top hose but so little flow the bottom hose will stay cold whilst the temp needle goes into the red. Ask me how I know Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 30, 2007 Share Posted October 30, 2007 Who he? I'm John Oops... Confused you with BBC.. Sorry... Quote Link to comment Share on other sites More sharing options...
Ex Member Posted October 30, 2007 Share Posted October 30, 2007 That's what I am now worried about I had the engine running for about 10 minutes, I then took it for a blast only about a mile, the temp Gauge was 4mm under the red line (this has changed since the disco block went in, about normal) I have measured the temp with one of those laser lights (don't know how good they are) and it was about 70 degrees and that was after a good run. perhaps it is working fine. I did remove the top of the boost bottle after the 1 mile run there was a bit of pressure, but nothing to make the water spurt out, and the water in the bottle was cold (very) don't know if that points towards anything, I know my V8 was totally different. Sounds like the gauge is not reading correctly. Check the thermostat as well (pull it and put it into boiling water). Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 31, 2007 Share Posted October 31, 2007 The boiling water check is one thing, as I discovered with my *new* thermostat though, it must have a bleed hole (sometimes has a little jiggly thing in the hole too) otherwise you get an air bubble the other side and it doesn't open as it should when in the engine. I had to take it out and drill a ~2mm hole, now it opens properly. Before it would hit 100deg and then finally pop open after a bit of revving, dropping back down to normal temp. Quote Link to comment Share on other sites More sharing options...
Monster Posted October 31, 2007 Share Posted October 31, 2007 Hi, I was looking into getting one of those sensors for my disco tdi install. Any reason why the fan sensor is on the exit of the radiator? I thought it had to go on the intake side after the thermostat. (That roughly where the temperature sensor for the guage is). Is your fan sensor adjustable or of fixed type? Unfortunately your diagram is a bit vague for me to see if you have the correct connections. Most relays have a number along side them to detemine which part is connected to what. This helps a great deal as it tell you the high power connections and the low power side. Also you show your thermostat switch as having 3 pins. This could be your problem. I assume it means that there is a common(input) a normally closed and an normally open contacts. If you have the NO and NC connections connected it will never work. Definitely use a fuse! Put one between the battery and the relay supply. In my experience it would be around 15 to 20As. The initial startup can blow a normal rated fuse. I also agree with landymanluke 'I would use the 'stat and override to feed the relay, rather than having the 'stat and relay in parallel.' I think what he means is to use the supply from the switch and go to the stat, back to the relay switcher terminal 85. The main feed with then come from the battery via a fuse to the relay 30 and then to the fan 87. If you bypass the x-sensor by touching the two cables together and the fan works, you know it is just the temperature sensor that is suspect or incorrectly wired. Use good thick cable for the battery/fan cable and buy yourself a nice crimping tool and terminals. Always handing for doing little electrical jobs. Stereo, spots, horns etc. Steer clear of cheap crimping tools though! Sorry to be simplistic, and apologies if i am being too crude. Vehicle Wiring Products have some great diagrams on relays/cables etc as well as some neat electrical gadgets! http://www.vehicle-wiring-products.eu/VWP-...lays/relays.php Although you seem to be on the right track let us know you get on. Cheers. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 31, 2007 Share Posted October 31, 2007 The three pins are a common, and two temperature ranges. i am using the lower range. If you use an on-off-on switch, you have three options to feed the relay with - a permanent 12v, nothing, and 12v via the 'stat. if you do all of this on the trigger side of the relay, it's all low current and much easier to wire, leaving just the relay and fan with heavy wiring. I found a mondeo fan blows a 20A easily on start up (inductive load), mine's currently running on two 20A in parallel (40A), until i get round to replacing them. I found that once started, the fan will run quite happily on 20A. Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 31, 2007 Author Share Posted October 31, 2007 I sent an email to X-Eng last night. This is their reply Dear Mark, Your circuit looks fine. You can of course check it by shorting together the two connections to the fan switch. Then your switch should just switch the fan on and off. You can test the fan thermostat by placing it in a pan of boiling water - the water actually needs to be boiling to get it to switch on, not just hot from the kettle. If there is a problem with the thermostat, we will of course replace it free of charge. Quote Link to comment Share on other sites More sharing options...
JST Posted October 31, 2007 Share Posted October 31, 2007 That's what I am now worried about I had the engine running for about 10 minutes, I then took it for a blast only about a mile, the temp Gauge was 4mm under the red line (this has changed since the disco block went in, about normal) I have measured the temp with one of those laser lights (don't know how good they are) and it was about 70 degrees and that was after a good run. perhaps it is working fine. I did remove the top of the boost bottle after the 1 mile run there was a bit of pressure, but nothing to make the water spurt out, and the water in the bottle was cold (very) don't know if that points towards anything, I know my V8 was totally different. The bottom hose is cold and the thermoswitch is in the bottom hose so it wont turn the fan on, surely that is how it should be? as Red says the Rad is working. Your temp guage is registering normal engine temp (all be it against a different scale - try a new sender replace the disco one for a def one) the gauge moved to where it should of and stayed there, the engine got to 70 deg, which also confirms why the fan wont come on (82 IIRC it needs to switch at the low end 87deg High) the system was beginning to pressurise. your fans works if you bypass the switch so no fitting issues with the fan. You need to get the switch to 82deg to get the fans on it just seems you haven't yet achieved this. i dont think there is anything wrong with it. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 31, 2007 Share Posted October 31, 2007 i dont think there is anything wrong with it. Agreed, if the engine is at standard temp, and the rad had sufficient teperature difference across it, the fan shouldn't be on, as it isn't needed. Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 31, 2007 Author Share Posted October 31, 2007 Ok update. I purchased a new Thermostat swapped it over and now the bottom hose gets hot so the guage was stuck shut, the temp gauge needle goes to just slightly over the white bar behind, a fraction in to the black but nowhere near the red, thats as hot as I could get it. I cant touch the top hose and can just barly touch the bottom one, but I still have no kick in from the fan. So either 1- I have the thermostat wired wrong 2- The thermostat is faulty 3- The water is not hot enough I think its boiling water time tomorrow and put a test accross the pins Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 31, 2007 Share Posted October 31, 2007 I said in an earlier post, your diagram shows you using the hotter switch of the two. I'm using the cooler switch, and it works fine. Quote Link to comment Share on other sites More sharing options...
JST Posted October 31, 2007 Share Posted October 31, 2007 i still dont get it if your engine is running at 70 deg your thermo wont open anyway and fan wont come on until higher temps 82 or 87 option 3. are you doing more than 1 mile warm up drives yet? sounds more like the thermostat you fitted now is just the lower opening one. if it was closed before even with the small weep hole the whole top hose wouldnt be that hot as it would be pushing into colder water i would have thought. Quote Link to comment Share on other sites More sharing options...
zulublue Posted October 31, 2007 Author Share Posted October 31, 2007 I said in an earlier post, your diagram shows you using the hotter switch of the two. I'm using the cooler switch, and it works fine. according to X-Eng diagram I have it correct, bottom left connector. I have not tested the temperature since, but it does feel hotter, before the bottom of the rad was cold now hot all over. You may still be correct that it is not reaching 82 degrees, is this the cut in temp is on the thermostat? X_Fan.pdf Quote Link to comment Share on other sites More sharing options...
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