49 replies to this topic

[VitcLJ]

LJ does not have the regulator. Gauges run off 12V as did all early holdens.

[Rockoz]

Skapinad.
Take the sender wire off the fuel gauge. If needle goes back to zero, then wiring OK. Earth it and it should go to full.
Temp gauge sounds possibly like an earthing problem.
First check I would do is see what happens with dash lights when temp sender wire taken off.
Check the dash to chassis earth connection next.
Then park light earths.

[Rockoz]

Semantics. Whether input, output or otherwise there is a power wire and a sender wire which is supposed to have a specific range of resistance (to earth) to suit the gauge.

My LX manual shows the regulator as a separate component so perhaps there isn't one on the LJ after all and you should be chasing shorts to earth? Seems strange that those three gauges would all have the same problem though.

Semantics maybe. But it does help to provide usable information in a standard tha t can be understood by a technical person.
Inputs are things that happen or are applied to make a result. Outputs are the resultant action. Input could be say petrol. Resultant output may be power. Obviously there are more inputs required and more outputs resultant.

Considering the age of the vehicles we are playing with it would not be uncommon to have multiple failures of this type. Earthing issues or lack of earth in particular is very common. So is corrosion on connections.
If chasing electrical problems, it is always best to start with the simplest and easiest test, then work your way through.

[Rockoz]

You can make up your own definitions that's fine, it doesnt really matter.
I thought your description of the inputs going to earth was very confusing.
for most people they think of the wire that goes into the gauge as the input, the 12V wire, as current is said to flow from +ve to -ve, where the current goes out, being the output.
No I wouldnt have used the terms output and input, just referred to the +12V side of the gauge and the ground/sender side...clear to everyone.

Perhaps the usable information you provide next time should be done in conjuction with actually looking at the circuit diagram(no regulator)

Yes a circuit diagram would have been handy. It is a little hard to diagnose a problem from words on a computer screen. But I did reasonably I think. Perhaps my 30 years of experience and trade papers helped me.
Both wires go into the gauge.
As far as the regulator goes, it absense makes no difference to the diagnostics i suggested.
Oh and I didnt make up my own definitions.
The definitions I used would be ISO standards. Dont know where you got yours from.

[rodomo]

Ok this is what i have found, talk about a wild goose chase and i do feel like a goose

Fuel sender is rooted, the gauge goes to full so i tried a HZ sender (which is wrong resistance i believe) and the gauge moved although it went opposite from the sender, when sender was moved to full the gauge showed 1/4 when sender empty gauge went full

Oil sender is rooted but the gauge come to life and shows low, i know there is pressure as i checked with mechanical gauge.

Tempurature gauge is now working I suspect it just had a bad earth on the body of the gauge because all i did was remove it then put it back on but rubed the two metal surfaces together (body of the gauge to earth/dash and it came to life. BASTARD. Could have sworn i did that before
I will see about the fuel and oil sender at rare spares

Problem solved here I believe?

[Rockoz]

My definitions, no I didnt provide any, but was guessing as to yours.
ISO standards? ,we are talking basic DC electrical circuits here....not black box devices.
Sorry if I have wasted my time here, hopefully you will think it through

Pretty sure I commented on your definitions.
ISO has a standard for most things.
No you havent wasted your time.
You have added some thoughtful insight.

[76lxhatch]

Don't leave a gauge that is shorted to earth for too long as it will get damaged and probably never read correctly again, even after fixing the problem.

[Rockoz]

Don't leave a gauge that is shorted to earth for too long as it will get damaged and probably never read correctly again, even after fixing the problem.

So I guess with that theory you should never keep a full tank of fuel for too long then?

[Rockoz]

Hey rockoz, thanks for the advice. I forgot to mention I did disconnect the sender wire and the gauge did exactly the same thing, which led me to believe it is earthed effectively ??

I also checked the connection on the temp wire and where it goes into the head its got a regular type female adaptor (like a speaker wire) just squished on to the little ball, was actually quite loose, so I am guessing if I get the correct one it may fix this.. I assume Repco or somewhere will have them?? thanks again.

When you shorted the fuel sender wire to ground what happened with gauge?
When you pulled the sender wire off what happened with gauge?

You need to check a couple of things here.
You have 3 variables from what I gather. Normal, Lights On, Indicators On.
Turn lights on. Check what gauge and dash lights do. Remove sender wire. Check what gauge and dash lights do.Earth sender wire and check again. Do same with the indicators.

Is the Oil Pressure gauge working properly?

There is a possibility that the problems are all related, or seperate as in Barts case.
A couple of minutes with a few simple tests can save hours of blindly groping around.

[Bart]

When you shorted the fuel sender wire to ground what happened with gauge?
When you pulled the sender wire off what happened with gauge?

You need to check a couple of things here.
You have 3 variables from what I gather. Normal, Lights On, Indicators On.
Turn lights on. Check what gauge and dash lights do. Remove sender wire. Check what gauge and dash lights do.Earth sender wire and check again. Do same with the indicators.

Is the Oil Pressure gauge working properly?

There is a possibility that the problems are all related, or seperate as in Barts case.
A couple of minutes with a few simple tests can save hours of blindly groping around.

Temp and oil gauge is now good
Fuel gauge not working but im sure its the fuel sender because i used the HZ sender and it worked, but when i swung the sender arm it would show full which is good but would show quater empty which is no good, im assuming this is because its the wrong sender? (HZ sender only for testing not installed different resistance??)

Edited by Bart, 04 February 2009 - 10:26 AM.

[76lxhatch]

So I guess with that theory you should never keep a full tank of fuel for too long then?

That's a bit different as the sender still has some resistance to earth even when the gauge reads full, having it shorted to earth is worse as you're putting too much current through the gauge

[Rockoz]

Yeah Bart would say that its because its wrong sender. The fact that the gauge moves is the main thing.
Bit of a bugger getting all senders to go like that. Whats the last gauge? Ammeter on them I think?

[Bart]

Yeah Bart would say that its because its wrong sender. The fact that the gauge moves is the main thing.
Bit of a bugger getting all senders to go like that. Whats the last gauge? Ammeter on them I think?

Cracked open the sender and found it was fairly corroded/suface rust on the coil and dull contact point. Also one end of the coil was ok but the other end was broken off the body of the sender which was the earth of course lol
Re soldered the coil wire on the body of the sender, making the coil slightly shorter (gauge is a tad off empty) cleaned off the surface rust sprayed WD40 to flush everything and it all worked, only thing is i have to solder the body together again because the little tabs have broken off

[Rockoz]

Top job done there.

[76lxhatch]

Whats the last gauge? Ammeter on them I think?

Voltmeter - doesn't require any sender so generally the most reliable!

[76lxhatch]

Well done on getting everything sorted Bart, I know from experience that gauges can be very frustrating!

[Bart]

Thanks to you guys and this forum i have been able to work out how to fix this problem.
You have steered me in the right direction so thanks again
Out of curiosity i have tested the resistance on the sender, i suspect it is a tad off spec as the coil of wire/resistor is a tad shorter (as it broke and resoldered), I measured 17.2ohm to 51ohms
Anyone know off the top if this is correct?
Cant be too far off as the gauge works fairly well.

[Tiny]

Well done bart!

You should go into guage repairs mate! that's exactly what the instrument man did to my sender when i had it repaired and calibrated to my fuel guage! (And when we installed the tank.. it now reads wrong...!)

Cheers!

[Bart]

Well done bart!

You should go into guage repairs mate! that's exactly what the instrument man did to my sender when i had it repaired and calibrated to my fuel guage! (And when we installed the tank.. it now reads wrong...!)

Cheers!

"it now reads wrong...!)" Im sorry to hear that mate, it really sucks when these niggly bits dont work. Allot of patients is definitely needed. Lets face it the old Holden guges wernt the best lol
One thing i also noticed is the amount of play (side ways) there was in the sender/arm, i actually spaced it with a small stainless washer as it effected the gauge reading slightly (jumped a bit) when i moved the arm side ways (before i spaced it with a washer)
Hey Tiny I got an HZ sender if you want it?

[Bart]

But then it may be better if you spend the extra and get a new sender if available.
Probably Rare Spares in Victoria

[Tiny]

Thanks Bart!

Really appreciate the offer mate!

I got a "reconditioned" one from Rare Spares for the drop tank, and it red perfectly on the bench test.

I Think that because of the angle of the tank and wehre teh fuel actually sits.. it reads about 1/8th tank higher than it is! starts to surge at just under 1/4 tank!

The old HQ senders sucked too because they were 0-30Ohms so any open circuit made the guage go to full deflection! the autometer guage suits that sender too!!

Cheers!

[Bart]

Thanks Bart!

Really appreciate the offer mate!

I got a "reconditioned" one from Rare Spares for the drop tank, and it red perfectly on the bench test.

I Think that because of the angle of the tank and wehre teh fuel actually sits.. it reads about 1/8th tank higher than it is! starts to surge at just under 1/4 tank!

The old HQ senders sucked too because they were 0-30Ohms so any open circuit made the guage go to full deflection! the autometer guage suits that sender too!!

Cheers!

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