I've broken it, engine temperature sender.

[FactBV]

I can't see it in the bible and the search is down again.

I had an intermittent engine water temperature reading for a short time before it went to zero completely, everything else was fine. So I took off what was a lot of old insulation tape that had been wrapped around the cable just before the sender at the front of the engine.

When I took it off there was a very small, what looks like a simple in-line resistor, that has broken. It doesn't look original as there are additional spade connectors either side of it. I presume that it is some some sort of trimming resistor for the temperature reading, but could be completely wrong.

I will try it tomorrow without the resistor and see what happens but any ideas? Is it matched to the temperature sender, so I need to get a new sender?

Thanks in advance.

Peter

[GJR]

I changed mine back in January. The original one has just one spade connector on the sender. I'm not sure, but I believe the originals were thought to be unreliable so some people opted to change it for a Landrover temperature sender. The Landrover sender required the addition of the resistor in order to make them read (or make the gauge read) the same temperature as the original TVR sender.

[timbotwo]

mines an early 500 and has the in line resistor. If I take it out of the circuit the temp gauge reads higher by 10 degrees

[FactBV]

GJR said:

I changed mine back in January. The original one has just one spade connector on the sender. I'm not sure, but I believe the originals were thought to be unreliable so some people opted to change it for a Landrover temperature sender. The Landrover sender required the addition of the resistor in order to make them read (or make the gauge read) the same temperature as the original TVR sender.

Thanks, very helpful. I had a closer look today and noticed that the body of the resistor seems to have come out of one of the very small end caps which is still attached to the wire. So I have managed to heat the cap and put a tiny blob of solder in it and then put the body of the resistor back in which seems to have held well. I've put some heat shrink around it and refitted it, hopefully it will work. Peter

[FactBV]

timbotwo said:

mines an early 500 and has the in line resistor. If I take it out of the circuit the temp gauge reads higher by 10 degrees

Many thanks, at least if the fix I have tried doesn't work, I can use it in the meantime by taking the resistor out and allowing for the temperature difference. Peter

[PeteGriff]

FactBV said:

Thanks, very helpful. I had a closer look today and noticed that the body of the resistor seems to have come out of one of the very small end caps which is still attached to the wire. So I have managed to heat the cap and put a tiny blob of solder in it and then put the body of the resistor back in which seems to have held well. I've put some heat shrink around it and refitted it, hopefully it will work. Peter

Hi FactBV, if it is just the resistor they are cheap and easy components to buy from the likes of Maplin. If it fails again take it out and take it with you to a Maplin outlet, probably find you will have to buy several but they are generally very cheap. All the best, Pete

[FactBV]

PeteGriff said:

Hi FactBV, if it is just the resistor they are cheap and easy components to buy from the likes of Maplin. If it fails again take it out and take it with you to a Maplin outlet, probably find you will have to buy several but they are generally very cheap. All the best, Pete

To be honest I did think just that as I watched the plastic colour coded coating discolour as I soldered it! Unfortunately, I don't have enough coating left to be able to identify it. It would be a bit of a long shot that someone knows what the rating of the resistor is..............but just in case someone does... it would be good to know if my fix doesn't work. Peter

[TVR Beaver]

Take a look here... I had this issue.. it does go off a bit... but may give you some pointers... I found the new senders to be out to my gauge?...

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

and may be this....

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by TVR Beaver on Friday 16th March 03:40

[FactBV]

TVR Beaver said:

Take a look here... I had this issue.. it does go off a bit... but may give you some pointers... I found the new senders to be out to my gauge?...

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

and may be this....

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by TVR Beaver on Friday 16th March 03:40

Really helpful, thanks. Yes mine looks exactly like the close up shot of the resistor in the first thread. The colours on the resistor are different but being just soldered in series between two spade ends.

From reading these threads, as has been mentioned, it just sounds like TVR had a problem with matching the standard LR sender to the temperature gauge that they wanted to use. The fix was a simple resistor in the circuit. Of course I should have just measured the resistance with the multi-meter Doh. Anyway, I have just done that with it in situ and it is reading around 9 ohms. I haven't had a chance to test it yet but will do over the weekend.

TVR Beaver - how are you able to get the search working. The only option I get is the google one!

[David Beer]

Why not go variable resistor, that's what to use when converting to the LR sender on serp engines. 200 ohm in that case.

[FactBV]

David Beer said:

Why not go variable resistor, that's what to use when converting to the LR sender on serp engines. 200 ohm in that case.

David, my griff is a Dec 92 4.0 pre-cat, does 9 or 10 ohms sound about right, 200 is obviously very different although I presume that it is a maximum of 200 and you adjust it down to get the temperature right......Don't know too much about these things!

[TVR Beaver]

I got mine set with a variable... then measured it and replaced with a normal resistor (for space really).... I think I ended up at 10 Ohm...
Its the TVR sender I got but still needed trimimg!
Do you have a known referance point.. for example when the fans come on when warm?... use this to calibrate?

BTW... I didn't use search... I just went back on my history

[FactBV]

TVR Beaver said:

I got mine set with a variable... then measured it and replaced with a normal resistor (for space really).... I think I ended up at 10 Ohm...
Its the TVR sender I got but still needed trimimg!
Do you have a known referance point.. for example when the fans come on when warm?... use this to calibrate?

BTW... I didn't use search... I just went back on my history

That makes me feel better, the reading was jumping around so it was 9 something, so in the ball park of your 10 ohms. I'll take the car out tomorrow and hopefully all will be well. If it doesn't work for some reason I do know when the fans come on so I have a reference. At the start I was more concerned as to why it was there and that I was going to need to replace the sender as it was matched to the resistor. Thanks for your help. Peter

[David Beer]

FactBV said:

David, my griff is a Dec 92 4.0 pre-cat, does 9 or 10 ohms sound about right, 200 is obviously very different although I presume that it is a maximum of 200 and you adjust it down to get the temperature right......Don't know too much about these things!

Yes the max is 200ohm and just twiddle down to set, i saw you were pre serp and just mentioned the serp mod that many have done. If you want one, drop me a mail.

[Alexdaredevilz]

I used 130 ohm restistor

[FactBV]

TVR Beaver said:

I got mine set with a variable... then measured it and replaced with a normal resistor (for space really).... I think I ended up at 10 Ohm...
Its the TVR sender I got but still needed trimimg!
Do you have a known referance point.. for example when the fans come on when warm?... use this to calibrate?

BTW... I didn't use search... I just went back on my history

Just taken the car our and all is good so it is a 9 or maybe 10 Ohm resistor; looks like I have one similar to you. Thanks for all your help.