The Toyota Landcruiser Owners Club

simonm · Posted: Sat Oct 25, 2014 17:54 Post subject: Speedo, fuel and RPM fault

Hi

I had a very rare fault where the Speedo and RPM gauge failed, simply showed nothing, then bounced back, that was about a year ago. More recently it has happened more frequently, Now the gauges don't work at all!

More recently, prior to the constant fault, what would "fix" it was going over a bump, or a sharp thump to the side of the cluster. Doesn't fix it now.

I have had the fascia apart (surprisingly easy) and taken the instrument cluster (gauges) out and checked the connectors. Nothing amiss and that didn't change anything. I didn't take the cluster apart so maybe a something else inside?

This now constant fault has also stopped the fuel gauge working, so something to do with the gauges: Fuel / RPM / Speedo Everything else is fine. I've checked all fuses.

Any thoughts. I'm sure this must have happened to somebody before. And am sure it is to do with the cluster. I guess there might be another post on this but cannot find it.

Toyota Colorado 90 1998 Diesel Manual about 130,000 on the clock - otherwise a brilliant vehicle!

Simon

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BobMurphy · Posted: Sat Oct 25, 2014 22:31 Post subject: Re: Speedo, fuel and RPM fault

Hopefully its just a bad connection somewhere rather than a break in the rather flimsy circuit overlay.

I would start by spraying all the edge connectors with electrical contact spray (i.e. Servisol) and loosen and tighten all those little screws that connect to the copper strips.

Then check all earth leads where they meet the chassis or body.

If that doesn't cure it you'll have to check all connectors further down the wiring loom.

As a last resort, get a working cluster from a breaker and swap the speedometer/odometer mechanics over. The timing belt warning light will be out of synch with your car as well, but that's a minor irritation and can be reset.

I have a similar intermittent fault with a Ford Focus where all the instruments die for a few seconds. I have cleaned all connectors but it still happens occasionally which is really annoying.

Bob.

simonm · Posted: Sun Oct 26, 2014 10:28 Post subject:

Thanks Bob

Yes, it feels like an earthing problem the fact that three gauges fail. On the plus side, its not intermittent ha ha ...

I'll take the cluster out again and clean and spray the contacts. I had gone through all the little screws, what I'll try to do is identify which of the very many circuit trails look to be common and then follow that.

I'll post any success.

BobMurphy · Posted: Sun Oct 26, 2014 12:01 Post subject:

You could look for a 'dry joint' amongst those soldered connections as well, though I'm not sure how easy it is to re-solder that type of circuitry.

Best of luck.

Bob.

simonm · Posted: Sun Oct 26, 2014 16:22 Post subject:

Fixed - well bodged.

Taking the cluster out again, cleaned using iso propyl with no change. So, followed the circuit board looking for a common connection between the faulty gauges. It was the ground, which if you look at Bob's photo, it is the screw head just below the gap between the two right hand connector strips.

I tested by running a wire from that screw through to the chassis - tell me if this is a bad thing - but everything then sprang into life. So, Ill make it a temporary fix while tracing the "ground" cable to see where the real fault is.

Simon

BobMurphy · Posted: Mon Oct 27, 2014 11:55 Post subject:

Good One

.

Do you have the Max Ellery Manual (with the wiring diagrams) ??

If not, I'll put the diagrams up here.

Your 'temporary fix' could well end-up being permanent Laughing

.

Bob.

simonm · Posted: Mon Oct 27, 2014 15:22 Post subject:

end-up being permanent ... yes, I expect so

No I haven't got the Max Ellery Manual, The wiring diagram would be great!

Thanks

Simon

eoincunny · Newbie Joined: 11 May 2014 Posts: 6 Location: Dublin

Having the exact same issue, however just with my Speedo, the revs and fuel and stuff works fine.

Have you any pictures of your repair?

Also Bob, could you post the wiring diagram? I would really appreciate it!

BobMurphy · Posted: Wed Nov 12, 2014 11:47 Post subject:

Wiring diagrams as promised (eventually, I forgot Rolling Eyes

).

They are not much use though, as the main instrument panel is called a "Combination Meter" and is just a black box.

On it there is a link to the 'Engine Control System' which is - naturally - another black box in the shape of the Engine Management ECU.

Anyway, here they are:

Hope this helps Confused

.

Bob.