Correct Electrikery Values at Temp Gauge

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Stuballsed

Stuballsed

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Gents,

Moving on with me temp gauge issues, does anyone know how to test the values of inputs to the temp gauge on my 300?

I have a test gauge that looks like it tests for just about every input, ac, dc, amps, etc. Can I connect this to the input wires at the gauge and find out if the input is within the correct parameters?
 
Hmmm, I was expecting to have a variable value as the coolant heats up, i.e. value cold to value warm? Varying resistance value??
 
Hi Stu,
Can you post the voltage at the sender when the engine is cold (but running), and when the gauge gets just into normal. Then I'll see if mine has the same values (although my gauge never gets out of cold, that's why I want to know). Also mine is a 200tdi but whats the difference (lets find out).
 
Dont know about volts but I had a meter on my sender last week and it started out at 0.300 ohms ? not sure if that was the right unit of measurement was right but as the engine heated up the value increased so it was doing its thing.
I have had serious issues with temp gauge/sender units recently and eventually bit the bullet and bought a new matched gauge and sender from demon tweeks for about 40 quid. Save yourself the hassle and just fit a new gauge its only half an hour to do the wiring and itreally is worth it for the peace of mind.
Thats why i have the laser thermometer as well . Been there know your pain
 
Less than 1 ohm seems too low, I suspect the needle would be off the scale at that, check that the dial was in the 0-200 or 0-2000 range (if it was meant to be 300ohms).

If the guage is all over the place I would change the sender first for the sake of a couple of quid.
 
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To be fair it was my mates meter and he set it up before we plugged it in . I know we were measuring resistance and like you said he might have fiddled with the range a bit
It deffo started at 0.300 ,300 or 3000 and moved up from there though.

I went down the new sender ,new gauge,another new sender, scratch head,laser temp reader, before getting new gauge and sender.
 
Yeh hey, the weekend has arrived. Will play with temp/gauge issues tomorrow.

heuer27: Details/link to the gear you got from Demon? (All the gauges seam to be £100 plus?
 
Stu, I have an original guage and original sender in perfect working order. PM me if you want them.

I replaced mine with a VDO gauge that shows actual temperatures and got the sender from Croytec, but the sender looks exactly the same as original so suspect I bought the same thing.

anyway, 300tdi 90 gauge and sender here if you want it.

G
 
Griffdowg - Cheers dude, will bear in mind. In the meantime, playing with my meter:

At the Gauge with ignition on only, I get 12.12v and 3.17v at the connectors.

At Gauge with engine running at idle, I get 14.34v and 3.5v at the connectors. (accepting some variation due to contact quality)

At the Sender, with the meter on 20k ohmms, negative lead in the sender cable socket and positive on the end of the sender, I get -4.6 with the engine off and -5.48 with the engine running at idle (no idea what this value is, but get no reading at 2000 and 200 ohmms).

Curiously, I get a similar -5.48 value when putting positive meter lead to the block. This would suggest the new sender I fitted is giving me a max resitance value from cold, and is therefore faulty? Unlikely?

Come on oh great and powerful guru's WTF?

P.S. The part number written on the Gauge is AMR 2631, will look this up to see if it is indeed a 300 gauge.
 
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Hi there got a stack unit which comes with sender £49 delivered .It comes with a wiring diagram. All you really need to do is replace the ring connector on the back of the original gauge with a spade connector and cut off the bulb and put two spades on those wires to get the led working . Simples :)
 
heuer27 - cheers for the link.

However, not quite ready to throw the baby out with the bath water just yet, I want to discover the fault or it'll haunt me forever. Plus I'd prefer to keep things original for now.

I don't think I have either the wrong parts or missmatched parts. The readings I got from the meter look suspect, so my only next guess is to try another new sender incase the last one was faulty. But, I'd still like to hear from someone on the readinging I posted above.
 
Right, I'm not going to let this wee bastid get the better of me, it's such a simple circuit.

Power comes into the gauge, it's effectively variably earthed via the sender. Right. Where is the fault. New sender, assume ok. 12v into the gauge (14v when running, hmm), assume ok.

New infrared temp gizmo reads 85 deg c at housing after 25m run, so real coolant temp ok.

Anyone know what the variation in resitance of the sender should be if I test that hot and cold (I guess meter set to ohmms and test between sender pin and block?

What variation should I get at return to gauge? Variable resistor in the line so should vary from a max at hot/cold to 2/4/6? at other extreme?

Help please landy sparkies?

Many thanks again for offer of new gauge and sender, but, I need to understand the problem. Bit like terretts syndrome...**** **** ****:p
 
Well, this IS getting the better of me now:( I can not find out design/spec values for power/resitance for the gauge and sender so does'nt matter where I stick me meter, do'nt know if the values I get are within range and therefore where the fault lies.

If anyone with a working gauge and sender can test then tell me, from cold, with engine running, voltage values at both possitive connectors on gauge, then both values again when warmed up this would be useful.

Even better, same voltage values, or restistance? at sender (I guess between sender wire and sender connector).

In the meantime, I have a Genuine LR sender on order, cause I've read some people getting two or tree faulty britpart ones.

Stay tuned :D
 
Well, picked up my new, GENUINE Land Rover sender today and swapped out the new Britpart sender I fitted a couple of weeks ago.

Anyone want to know what happended?
 
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