Temp Sender Resistance

[willem]

Hi all,

I saw a table somewehere on the web with engine temperatures and the correct corresponding resistance of the gauge sender. I can not find it again for the life of me.

Anybody knows where to find this again ?

Cheers,

Willem

[GreenV8S]

I've got the figures for the ECU sender, but the gauge uses a separate sender which may not be the same rating. Which one are you after?

[dave_p]

david beer...no doubt he will be along shortly...I think he might know and thing or two on this.

Dave

[GreenV8S]

Characteristics of the water temp sender used by the ECU are as follows:

deg C Ohms
-10 9200
0 5900
20 2500
40 1180
60 600
80 330

All the fuel, water and air temp senders I've come across have had the same resistance characteristics.

The sender used by the gauge may have the same characteristics, but I wouldn't count on it.

[david beer]

daveP, are you saying im like a bad penny !!
Heres the voting from my Rangie, normal running 88 degrees, spare sender on top of head 45 ohms, ECU sender 230 ohms. Not in the TVR today, but should be the same, so Willem, you should be able to see if its your sender.

[willem]

david beer said:

daveP, are you saying im like a bad penny !! Heres the voting from my Rangie, normal running 88 degrees, spare sender on top of head 45 ohms, ECU sender 230 ohms. Not in the TVR today, but should be the same, so Willem, you should be able to see if its your sender.

David B,

I am looking for the ratings for the one in front of the engine as well as the "spare" one on top (for comparison), which I've seen somewhere is totally different to the ECU one. But then, I can't even remeber where I saw it - so don't take my word for it !!

BTW I'm off to buy a variable resistor to "tune" the spare sender one on top to work with the existing gauge - unless the kit that I ordered from you (can I mention it here ?) already contains such a conversion ? Bfore I use the one on top, i want to check the resistance to make sure I'm not going from one faulty one to another.

BTW the PO gave me all his documentation on the car. Now I have an owners manual at least (still waiting for the bible ordered from TVR Club). I see from the invoices, that he had an ongoing battle with the same problem.

Regards,

Willem

[dave_p]

david beer said:

daveP, are you saying im like a bad penny !! Heres the voting from my Rangie, normal running 88 degrees, spare sender on top of head 45 ohms, ECU sender 230 ohms. Not in the TVR today, but should be the same, so Willem, you should be able to see if its your sender.

Hi David,

Not at all..I knew this one was up your street..as you helped me in the past wit my temp problem..I used one of your variable resistors.

I will need to talk to you about boot opening kit..are you still doing them?

Dave

[shpub]

Rather than tune things.... why not run a temp check on the car first to see if the guage is accurate or not and to confirm that the car is running normally. The remote IR thermometers or a contact electronic one are ideal for this.

Any overheating or suspicion should be checked this way first. If that is OK then yes the guage may need some adjusting. If it doesn't then there is a cooling problem and it is time to start investigating.

Steve
www.tvrbooks.co.uk

[willem]

shpub said:

Rather than tune things.... why not run a temp check on the car first to see if the guage is accurate or not and to confirm that the car is running normally. The remote IR thermometers or a contact electronic one are ideal for this. Any overheating or suspicion should be checked this way first. If that is OK then yes the guage may need some adjusting. If it doesn't then there is a cooling problem and it is time to start investigating. Steve www.tvrbooks.co.uk

Steve,

I've checked and it is a gauge/sender problem.

All,

I now suspect hat the sender gets fluctuating voltages from the gauge/dash. Measured between 5.03 and 5.6 Volt depending on aletrnator rrunning or not and what equipment is on. Now to track that one down ....

Off on a business trip for 3 days so you'll not see any progress reports.

Thanx for all the info and suggestions.
Willem

[IPAddis]

shpub said:

Rather than tune things.... why not run a temp check on the car first to see if the guage is accurate or not and to confirm that the car is running normally. The remote IR thermometers or a contact electronic one are ideal for this.

How accurate at the IR thermometers? Surely they can only measure the external face of the swirl tank which could be several degrees colder than the fluid within?

I've been tempted to get one but I've never been convinced.

Ian A.

[GreenV8S]

Very true, but if the outside is hotter than the nominal running temperature you can be pretty sure it really is overheating!

[david beer]

You can get stick on sensors for less than a pound from Farnell, ok you have to buy 10! One type is accurate to 1 degree C, but only does the one "peak" reading. The other is accurate to 5 deg C and can be used over and over again. I use them for testing various bits and bobs.

[shpub]

IPAddis said:

How accurate at the IR thermometers? Surely they can only measure the external face of the swirl tank which could be several degrees colder than the fluid within? I've been tempted to get one but I've never been convinced. Ian A.

Pretty good. Use it quite a lot to see how hot a barbecue is, how warm the pond is and whether the fish get fed and so on. It even dissapeared into the kitchen when the local Gas fitter's meter died and he needed to measure the boiler's operation...

Compared it with a thermocouple based tyre pyrometer and there was about 1 degree difference ish.