Weak Volt Signal On Sender Units

[GJM85]

I've always had issues with inaccurate instruments in the cluster of my ke20. I believe all issues are related & are as follows.

 

#Charge light glows when wipers, reverse lights, interior fan or indicators or on. When all the above accessories are on and the car is running, voltage at the battery is 12+ volts. So that rules out the alternator.

 

#When the fuel tank is full, the gauge reads just over half a tank. Inspection of the dial shows it's in no way bent or damaged & voltage at the sender fluctuates between 1 & 10 volts.

 

#When the car is at full operating temperature the gauge reads just on the first line. As above voltage fluctuates between 1 & 10 volts.

 

#The handbrake warning switch doesn't work at all and voltage is less then 1 volt.

 

I've tried 2 different clusters and nothing changed.

Oil sender works fine and has between 10 & 12 volts.

It's been 2 long years I've been at this and short of pulling the whole loom, I'm all out ideas. So before I call the auto electrician, has anyone got anything?

 

Cheers

Gav

[you_nes]

I've never seen the back of a ke2x cluster but the ke3x-5x has a voltage regulator exclusively for the fuel/temp senders, have seen 7 & 10v versions. when the 10 v one on my 55 died it did exactly what you described (fluctuated between 1-10 v) can be replaced with one from jaycar (some fiddling required).

 

that will not fix your glowing charge light issue though, still haven't gotten tot he bottom of that one( I have the same issue).

 

also the sender has to be matched with the cluster (i.e. if your cluster is supplying 10v to a 7v temp sender it will read high)

[GJM85]

This is the back of a ke20 cluster.

 

[GJM85]

Upon closer inspection, the temp dial doesn't sit at the same point on either cluster.

Still doesn't explain the varying voltages at the senders.

 

[GJM85]

So the voltage at the instrument cluster is irregular as well. I cannot see an indication of a regulator on the cluster unit.

I did notice on the green film the '7v' at the gauge terminal.

So perhaps I have the wrong voltage regulator all together.

I bought second hand, from this forum & installed it when I first rebuilt the car. It was marketed as a ke25 regulator.

Would there be a difference?

[you_nes]

Hmm..., that looks sort of similar to my ke3x cluster which has the 7v regulator hidden in the fuel gauge. you can tell by removing the gauge and looking for a bi-metal strip / resistor inside it.

 

You can test it by temporarily feeding it 12v, be careful not to leave it on for too long though otherwise you might let the smoke out. from the look of your picture the top bolt on the left of the photo is +12v, the bottom bolt on the left is earth (check that these by tracing it back to the loom connector which you should be able to find a wiring diagram for as i'm not 100% sure!).

 

When you hook those two up, use a multimeter between the middle bolt (7v) and earth to check if its outputting 7v. If its not then that's a problem. you should also be able to see the fuel gauge needle rise gradually all the way to full, if it doesn't rise or if it jumps to full in a nanosecond then that's also a problem (one that i don't know how to fix)

 

If its broke you can cut the wire that feeds this part and replace with a 7808 reg (8v) like in my photo below. The only downside is that the gauges will be much slower to rise initially (that bimetal strip that you cut out is there to give 12v initially before tailing off to a constant 7v, your new setup wont do that) and your gauges will read slightly high (8v instead of 7v being supplied to the sender).

 

The article I used as a guide to do this is here. ... http://holdenpaedia....tage_Regulator: (kingswoods and toranas have a similar set-up)

 

 

P.S. the reg in your engine bay (or strapped to the alt) is probably fine. the item i'm referring to is a separate low power reg that takes the 12v that your alt is outputting (which fluctuates a bit with load) and drops it down to a lower constant voltage (so your gauges don't also fluctuate with load)