Sender for AC temperature gauge

Sender for AC temperature gauge

Author
Discussion

ATE399J

Original Poster:

729 posts

236 months

Wednesday 20th June 2012
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I'm getting fed up with looking at a temp gauge reading about 120° when I know it's about 30° lower. I know the problem is that I have a Ford sender and an AC gauge. I've been told that I need a Vauxhall sended but can't remember which one.

It isn't an easy swap because the motor has been changed at some point so the sender hole on the manifold is sized for the Ford unit. This means that, potentially, to fix this problem I'll need to take the manifold off and have it machined to suit the correct sender.

Apart from putting a resistor in line to make it read corectly at/about the working temp does anyone have a clever fix?

tomtrout

595 posts

162 months

Thursday 21st June 2012
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I beleive the orignal unit was from a V Ventura. Not too many of those still around!

thegamekeeper

2,282 posts

281 months

Thursday 21st June 2012
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Adrian@ said:
Thats the one. TVR were using it for several years before Vauxhall invented it.

ATE399J

Original Poster:

729 posts

236 months

Monday 2nd July 2012
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Sorry, been away for a while. Thanks for the responses Adrian, Steve, but I have to ask a stupid question.... The fleabay link points to a whole page of temp sensors, which one did you mean specifically or do they all work with the AC gauge?

nwarner

612 posts

259 months

Tuesday 3rd July 2012
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Below is a pic of my spare which is the same as the one I have fitted. I hope that helps.


ATE399J

Original Poster:

729 posts

236 months

Tuesday 3rd July 2012
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Thanks smile

ATE399J

Original Poster:

729 posts

236 months

Monday 9th July 2012
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Bought and installed sender... turn on ignition & gauge reads just below 40° (i.e. barely moves). Ran engine up to point where Kenlow cuts in..... temp gauge reads just over 40° .....scratchchin

Putting a multimeter across the unit it has a resistance of about 70 ohms (cold), the one I took out (which over reads) is about 700 ohms cold. Nigel, any chance you could check your's? At least then I'd know if the unit is U/S or if it's the wrong one. I'm assuming TVR didn't put any clever resistance wire in the circuit, because I didn't when I re-wired it.

P.

nwarner

612 posts

259 months

Monday 9th July 2012
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If I get a chance I'll try and measure the resistance tonight.

Nige

jpa

218 posts

230 months

Monday 9th July 2012
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I have used one from a modern Vauxhall (vectra or cavalier I think) at the scrapyard and it is spot on. I have tested it using a laser thermometer and it appears to work within a degree or two.

nwarner

612 posts

259 months

Tuesday 10th July 2012
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I measured mine last night and the resistance reads 800 ohms.

ATE399J

Original Poster:

729 posts

236 months

Tuesday 10th July 2012
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Thanks Nige, looks as if I'll be sending it back then frown

aztvr

7 posts

214 months

Thursday 12th July 2012
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If anyone comes up with a part# or a specific year make and model of the car that uses an equivalent resistance range for its temp sender I would really like to know. I can't go pick up a used one; but, maybe I could find a way to order a new replacement. (My gauge is not accurate either because of the incorrect sender.)

Jim
'71 Vixen

ATE399J

Original Poster:

729 posts

236 months

Friday 27th July 2012
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All,

With a saucepan of hot water, a thermometer and a multimeter I calibrated the sender (giving a graph of Temp vs resistance) then with a potentiometer (variable resistor) I calibrated the gauge (again temp vs resistance). As I suspected the two are miles different but, but putting a 180 ohm resistor in parallel with the sender (using R=1/((1/R1)+(1/R2)) to calculate the value needed) I got a good match (on paper) of the two curves. Have wired this in at the gauge and it seems to be giving sensible readings now.

Incidentally, when I took the gauge out to do this I noticed that the gauge is marked as 24V and the power side is fed by a length of resistor wire, is this normal?

Phil

dmilsted

3 posts

259 months

Wednesday 18th February 2015
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I have been recommended to resurrect this somewhat old topic in an attempt to obtain some guidance / information on the following:- I have been running a Vixen S2 for 15 yrs during which it has always had full AC instrumentation and an alternator. The AC temp gauge always soon gets to 200+ and stays there, without boiling so far. Its definitely got an AC sender. I have been advised that the gauge is probably reading high due to a combination of the alternator and AC instrumentation. Has anyone out there managed to overcome this problem and is successfully running AC gauge and sender on an alternator equipped 1600 crossflow?
Doug

tomtrout

595 posts

162 months

Wednesday 18th February 2015
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Im running original AC gauge with a Viva sender and alternator conversion. Normal running the guage sits at around 190-195 F. I also run an electric fan with adjustable thermostat which kicks in at approx 205-210 F.

RFC1

1,107 posts

196 months

Wednesday 18th February 2015
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dmilsted said:
I have been recommended to resurrect this somewhat old topic in an attempt to obtain some guidance / information on the following:- I have been running a Vixen S2 for 15 yrs during which it has always had full AC instrumentation and an alternator. The AC temp gauge always soon gets to 200+ and stays there, without boiling so far. Its definitely got an AC sender. I have been advised that the gauge is probably reading high due to a combination of the alternator and AC instrumentation. Has anyone out there managed to overcome this problem and is successfully running AC gauge and sender on an alternator equipped 1600 crossflow?
Doug
I cant help except to say WOW your 1st post in nearly 13 years as a pistonheads member !!

tomtrout

595 posts

162 months

Thursday 19th February 2015
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Adrian@ said:
Andy are you still running the RB340 unit to allow you to do this? If so can I do a comparison to what I have to convert please.
before I send it on to Doug.
Adrian@

Doug, I have found my wiring diagram that shows the conversion with the alternator and RB340 unit in place since we spoke. I will forward it on to your aol.com address.

Edited by Adrian@ on Wednesday 18th February 22:07
No, I ditched the regulator but I am using a little solid state voltage stabilizer to power up the AC guage. To be honest I don't know if it makes a difference or not because I've not tried running without it. It cost peanuts and I took the decision that when I had the dash off and was installing the new loom to wire it in to provide some steady volts. Looks like it might have been a good decision.

tomtrout

595 posts

162 months

Thursday 19th February 2015
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Adrian - I always keep my fingers crossed with every job I tackle on my vixen! I can't remember exactly which stabilizer I bought but I'm pretty sure it wound the input voltage down to a steady 10v. Yes I also used it to power the fuel gauge which also works fine.

tomtrout

595 posts

162 months

Thursday 19th February 2015
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I've got one but I must say it is more of an ornament than a useful gauge!

Hansoplast

570 posts

159 months

Tuesday 10th May 2016
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Hello

I have a problem with my sender or temperature gauge in my TVR Vixen.
Searching on this forum did not help me (up to now).

I bought a sender from Burton so this item should be oke. It's the type with white collar.
http://www.burtonpower.com/temperature-sender-earl...

Checked the resistance (reading 440 ohms) that decreases when hot after some minutes running the engine.
But no reading on the gauge. The original AC type.
Checked the power to the gauge and earthing directly to the block shows max reading.

I ditched the regulator and there is (as original) no stabilizer.

Whatever is wrong?


Hans