Glow Plug Power/ Temp Switch

[marinabrid]

hi on the tdi 110 98year, no power to glow plugs have just found out. when i disconnect the temp switch with the 4 wires on i get a suppply to the plugs, have been reading about it it seems common that the fan runs with a cold engine im not getting that, im a bit confused, is the switch telling the brain its hot and dont need glow plugs ? I had in he toolbox an old temp switch that was on a previous gal same type 4 pins and yellow ring, i swopped it for this but just plugged the wire on without fitting it in the water , the same thing, no power to glow plugs. unplug and i get power is it the relay the switch or what !!!! if its the glow relay in the fuse box where do i find this also many thanks

[anadin]

had same prob last week , its wierd B) but yes change temp switch , its linked to ecu

[marinabrid]

thanks for that anadin, i got a headache as it is, but why when i tried the older one from the toolbox , although i didnt fit it into the system i just plugged it on, it still gave no power to plugs

[anadin]

 

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[anadin]

sorry keyboard locked on me B) just read your other post , have exactly the same prob , the coolant temp switch will improve the cold start, it has to be plumbed in to read the temp ,but i havnt sussed the warm starting prob yet havn't had time to look into it, how long has your been playing up as ive just got this one and dont know wat has been messed with ?

[marinabrid]

sorry keyboard locked on me B) just read your other post , have exactly the same prob , the coolant temp switch will improve the cold start, it has to be plumbed in to read the temp ,but i havnt sussed the warm starting prob yet havn't had time to look into it, how long has your been playing up as ive just got this one and dont know wat has been messed with ?

seemed to start a month ago, i cant fathom out that as these cars usually start very well hot or cold, will try a new switch, today and see what happens. wonder if the relay has anything to do with it, but where in that messy fusebox do you find it !

[anadin]

sorry keyboard locked on me -_- just read your other post , have exactly the same prob , the coolant temp switch will improve the cold start, it has to be plumbed in to read the temp ,but i havnt sussed the warm starting prob yet havn't had time to look into it, how long has your been playing up as ive just got this one and dont know wat has been messed with ?

seemed to start a month ago, i cant fathom out that as these cars usually start very well hot or cold, will try a new switch, today and see what happens. wonder if the relay has anything to do with it, but where in that messy fusebox do you find it !

 

havnt delved in yet but lot of the relays behind fuse box it should unclip :lol:

[marinabrid]

sorry keyboard locked on me :16: just read your other post , have exactly the same prob , the coolant temp switch will improve the cold start, it has to be plumbed in to read the temp ,but i havnt sussed the warm starting prob yet havn't had time to look into it, how long has your been playing up as ive just got this one and dont know wat has been messed with ?

seemed to start a month ago, i cant fathom out that as these cars usually start very well hot or cold, will try a new switch, today and see what happens. wonder if the relay has anything to do with it, but where in that messy fusebox do you find it !

 

havnt delved in yet but lot of the relays behind fuse box it should unclip :lol:

 

 

sorry keyboard locked on me :16: just read your other post , have exactly the same prob , the coolant temp switch will improve the cold start, it has to be plumbed in to read the temp ,but i havnt sussed the warm starting prob yet havn't had time to look into it, how long has your been playing up as ive just got this one and dont know wat has been messed with ?

seemed to start a month ago, i cant fathom out that as these cars usually start very well hot or cold, will try a new switch, today and see what happens. wonder if the relay has anything to do with it, but where in that messy fusebox do you find it !

 

havnt delved in yet but lot of the relays behind fuse box it should unclip :16:

whats the basis of a hot start ? what is involved cant fathom this, ive read every topic on the forum yet still im stumped ! does the temp switch feed the relay then the relay power the plugs ? why does it give power when the temp switch is unplugged !!!!

[Vanbursta]

Yes the ECU uses the temp switch to signal the relay to kick in. You get voltage when you disconnect it because the ECU can't get an accurate reading so switches to LOS for that part of the circuit.