AU Cluster Gone Mad! Need Urgent help PLEASE!!

[Swordsman88]

Hey guys and gals in AU land.

Sorry to intrude as a non AU owner but I post on behalf of my dad who owns an AU2 SR and is truly at wits end RE a cluster/guage issue. Background is simple enough, over the last few years at very intermittant times the car has had starting issues where it will not crank at all...just a click (not battery etc.).

Then 4 months ago the cluster (all the guages or some of them..primarily speedo/rpm) would fail when engaging cruise control. Then after restarting all was good. Then failures of cluster became more frequent, just when driving along. Eventually the LCD screen went screwy (jumbled figures etc.). When it failed a buzzing sound (reasonably loud) was reported from the dash area and it continues as long as power is left connected even after you shut the car down.

We had the car tested by auto electrition in terms of alternator, battery and earthing etc. He said all good, battery a tad low so put in a new one. Then we took the car to Ford dealer (was still going mad....probably getting more frequent) and they said they found a 'miss' under acceleration that may be throwing the dash out (??) and recomended new cluster and new spark plugs and leads. Problem was the leads and plugs were changed only 6 months before by our own mechanic.

We put in a second hand police cluster (worked fine) and all was good but then it failed again today with the speedo not working. Then after disconection of the battery (which sometimes fixes it) the buzzing sound returned and the LCD screen has gone screwy like the last cluster.

Anyone on here know WTF is going on? If the car was with me i could take a look at a few things gut its 1500kms away and i don't have access to it. Its causing alot of issues because although the car runs fine throughout this process its very hard (and illegal) to drive it (esp highway work) with no speedo and my mum needs it for work. Any help much much appreciated. I suspect BEM (due to earlier starting issues) or maybe ECU (not sure on the latter) but am at a loss at this point. Electrics is not my strong suit but i thought the BEM was responsible for all the info going to the cluster and if its not cluster related (happened to two different units) than it seems like the culprit.

EDIT: Further info. We tried to transfer the chip with the kms from the old original cluster to the new one but when the 'intrument technicion' dude fired it up on his rig he said the ldc readout was still buggered and he didn't know if the chip would hold the kms properly and still work?? Maybe something is eating these clusters alive...

[Mr Hardware]

We had a cab do this
We found it was it's alternator throwing out all sorts of crazy random spikes in voltage. Get a new alt and make sure your earthings around the place are doing their jobs.

[Mechan1k]

Also have heard of issues with loom connection between the passenger kickpanel where the ECU is and across behind the dash to the cluster ... there have been known pinch-points which can cause screwy readings with the cluster as well.

But I would be checking alternator first .... then go hunting for the harder stuff.

[Swordsman88]

The alternator was suspected some time ago but it apparently was ok when tested. Surely such spikes in voltage would be obvious when put on a multi no? Unless they only happen from time to time and it wasn't doing it at time of the test.....

[Donny]

Voltage reg could be intermittant and send volt spikes through the system.. If that was the case, Id wanna get that checked before it sends a big fat one straight into the ECU and kills it..

[Swordsman88]

Originally Posted by Donny

Voltage reg could be intermittant and send volt spikes through the system.. If that was the case, Id wanna get that checked before it sends a big fat one straight into the ECU and kills it..

Voltage regulator? Not familiar with that unit (not into electrics)...i take it has something to do with the alternator?

[Mr Hardware]

Yes. Inside (or just outside sometimes) every alternator there is a voltage regulator. It is mainly there to stop overcharging and spikes, usually capping voltage at something like 14.6v.

[Swordsman88]

updated on this situation. Car is going to auto elec to have a alt. earthing and some other things checked for any voltage spikes etc. He said it was ok last time so not really confident. Will see what happens anyway....

[Swordsman88]

Car was tested by auto electrics. Couldn't find the source of the spike. Did discover a very small leak of power steering fluid which some of went onto the alternator. not good as i am aware its a known cause of this sort of thing. Replaced alternator and fixed powersteering leak (well sort of...mechanics changed hoses then leak was still present but its all good now....i hate people that can't do their job properly grrr!)

Ford dealership has claimed the spike is from the ignition system (leads/wires or possibly coil) but our auto elec (who i am growing to dislike more every day....very suspect some of his ideas imo) says he can't find any evidence of that. I have just aranged for ANOTHER cluster to be readied so once we finally fix the issue we can install that and hopefully all is good.

Any of you guys aware of this coil/spark plug related issue causing this problem? Bear in mind that the leak from the power steering was only very minor and only noticed in the last few weeks so i still think it is not at fault. Was probably this ingnition problem all along....

[Beer Baron]

Checked the earth near the PCM in the passengers side kick panel ? If the PCM hasn't been removed before it will be riveted to the body.