Tested Gauge Clusters

[geoffayres]

........I know his cluster was playing up.

He has serious problems.........but, how did you find out??

[Cuppa]

He has serious problems.........but, how did you find out??

Oi, don’t tell everyone ..... it’s personal!

Seriously though ..... the problem was fixed....... with a little help from my friends & an extra strap.

[BigRAWesty]

@mudnut, a bloke is splitting a gq in Portland.I'll get his number to you if you like.

But if you do something soon I'd like mine tested..

[Yendor]

Mudnut, Do you have a spare GQ instrument cluster or do you know if there is a voltage regulator on the supply feed to the gauges?

I don't think there is but I'm not 100% sure.

[mudnut]

Wow, blokes the Questions are coming thick and fast now! I have spent the last couple of hours researching equipment and variable resistors.

Yes, please, Kallen. PM me his number. I have the cluster, out of my 4wd corolla to do some initial tests on as a guide to what components I will need to replicate gauge readings etc. Finding cheap variable resistors with a good wattage rating is proving to be fun. I may have to parallel some double gangers to cope, so I should get something going in the next few weeks. In the Haynes manual I have, there are some simple tests for the gauges.


Yendor, I haven't got a cluster, but hope to have one soon. I'm hoping all of the Q clusters have the same connectors even though Diesel and petrol models differ. I will scour the manuals and see if there is some sort VR in the circuit.

Edit. The electronic manual shows three different gauge clusters, with the what looks like identical sockets.

[mudnut]

Yendor, so far all I have found is the resistor circuit in parallel with the speedo and voltmeter and then in series with warning lamps. This would act a a basic regulator. I suppose they rely on the alternator VR. Please correct me if I am wrong.

I am having trouble finding the expected voltage readings for the tacho in the three manuals I have. I am a bit averse to testing across the terminals with my moving coil meter. An auto elec warned me off doing that many moons ago, but I can't, for the life of me remember the reason behind it.

[Yendor]

Yendor, so far all I have found is the resistor circuit in parallel with the speedo and voltmeter and then in series with warning lamps. This would act a a basic regulator. I suppose they rely on the alternator VR. Please correct me if I am wrong.

I am having trouble finding the expected voltage readings for the tacho in the three manuals I have. I am a bit averse to testing across the terminals with my moving coil meter. An auto elec warned me off doing that many moons ago, but I can't, for the life of me remember the reason behind it.

I didn't think they did have a VR mounted in the instrument cluster.

I'm just thinking if there was, then this is what might be wrong with Kallen's.

A digital multimeter will be fine to use or even better a new scope

I remember seeing someone posted scope reading, I think for engine RPM and vehicle speed. It was awhile ago......I will see if I can find it later tonight.

[mudnut]

What price would everyone expect to pay for a secondhand cluster and partial wiring loom?

[BillsGU]

Digital meters have a much higher input impedance than moving coil meters (Meg ohms as opposed to kilo ohms in some cases). This means that when you poke a digital meter into a circuit - the meter does not have an effect on the circuit operation (ie the meter does not change the overall resistance of the circuit). Moving coil meters due to their lower input impedance (especially the cheap ones) can do anything from changing the characteristics of a circuit and giving you incorrect readings to adversley affecting a circuit and stopping it from working or even damaging the circut.

[mudnut]

I have a cheap digital multi meter, but it likes to give odd readings sometimes, so the "Dearest, I need a good digital meter too" will come into play when I let her read your post.