H Reg G60 Corrado Instrument cluster dead / dying??

[br1gg5y 10]

Hello Everyone,

I wonder if anyone can help. I've been suffering electrical gremlins', which I've now all resolved apart from the instrument cluster, I've tried search but cannot find a thread that matches my exact issue;

 

- The car does start and run

- The LCD for the clock / MFA works

- The LCD for the odometer works

- The arrow shaped lights work when I switch the indicators / hazard lights on

- The blue light indicating I put the main bead headlights on works.

 

Nothing else on the instrument cluster appears to work

Everything else on the car electrical appears fine unless I've missed something

 

I've ordered a 2nd hand replacement cluster, but I have full service history and really don't want to lose that due to swapping out the cluster, as I believe the mileage is stored on the board of the cluster on my early car and not the ecu. Also the entire unit isn't dead., The electrical gremlin's were the immobiliser just dying (refused to disarm) so I removed that. None of the wiring interfered with the wiring for the instrument cluster. Same for the alarm that also appeared to be doing bugger all. So I removed it. and some other dodgy wiring for what seems like was for a boost gauge. I'd hoped I'd just disturbed something resulting in a bad connection. or blown a fuse by accident. No such luck.

[marks2 0]

Do you have a multi-meter?

 

If so start by checking you have 12v between pins 3/5 (Ground) and pins 11 /13 (B+) on the cluster with the ignition on. If you look at the back of the cluster there should be a small hole in the housing (approx 1.5mm in diameter). Pin 1 is the nearest to that hole.

 

The rest are numbered as follows looking at the back of the cluster.

 

14.....1

28.....15

 

Assuming you have 12v on these pins then the next check is the voltage regulator that supplies the pcb inside the cluster.

 

This is a LM2940T-10 (TO-220 device)and is visible beneath 2 rectangular cut outs on the opposite side. Check 'LM2940' is written on the device.

 

The tab with the pop rivet through it (securing it to the heatsink) is ground and with the tab at the top the pins are from left to right In, Ground, Out.

 

Check the Out pin with the ignition on. It should be 10v or there abouts. Be careful not to short the pins when taking measurements.

 

If this makes no sense and your near to Reading I can help.

[br1gg5y 10]

thank you, Yes I have a multi metre, I will be looking into this at the weekend. My replacement cluster has arrived as well. SO fingers crossed.

[br1gg5y 10]

you were correct pin 13, was not supplying any voltage. however I traced it back to the fuse box and it was dead at that end as well. I had a look at it seemed fine at the socket where it connects to the fuse box. so as a quick check, I bridged pins 11 and 13, to see if that was the end of my woes it wasn't :(

 

- the speedo is not working, I did take off the hose that connects to the rear of the speedo. and with the engine running and it not connected I could hear rushing air. I have re connected it. but perhaps I've not seated it back correctly I will try again. unless there is something else I might check?

 

- the ignition is always on. with the key out the ignition lights are on. How might I tell if this is a barrel or wiring issue?

 

all very frustrating as this all started when fitting a new head unit, then the immobiliser wouldn't un arm , So I removed it. it interrupted 2 wires on the ignition. that merely needed joining back up