Electrical madness

[G60rob 0]

Could there be a connection between any of this lot:

 

ABS light sometimes stays on. Stopping and turning the ignition off and on again resets it and then it can be alright for weeks.

 

The wipers sometimes won't start except in the full speed position, but then switching to a lower speed is OK.

 

The heater blower started playing up last week - occasionally it won't come on at all, or the fan speed drops. Mostly it's OK, though it has been a noisy for a while. Just worn bearings maybe?

 

Before cleaning the car (doesn't a year just fly by), I put the spoiler up using the under-dash switch and now it won't go back down. It hasn't been making any graunching noises as if it needs lubricating. The fuses are OK.

 

I wondered if the load reduction relay might be involved, but decided not as it clicks healthily when I turn the ignition key.

 

The rev counter needle often flicks about, or goes back to zero for a while, but works some of the time (thought it was the wobbly pin on the back, but the resistance across my test meter doesn't change when I wiggle it.)

 

It seems strange that these things are happening one after the other, but I suppose it could be just corradoincidence?

 

('92 G60 85 000 miles)

[bcstudent 0]

I suppose it could be just corradoincidence

:lol:

[RW1 0]

Took a look at this.

 

There’s no real common theme on the listed problems. The “x” relief relay doesn’t power them all. Neither are the earth sides commonly linked to one point.

 

15 Ignition ………. X-relay …………. Earth………… Circuit

 

……………………………..Y………………….Stud39……….. ABS

……………………………..Y…………………Fuse Box………. Front Wipers

……………………………..Y………………….Stud43………… Heater Blower

…………Y……………………..………………Fuse Box………. Spoiler Down

…………Y……………………..………………Fuse Box………. Rev Counter

 

Other X relay circuits – Heated Rear Window, Rear Wiper & Sunroof.

 

 

As the Corrado engine is running normally??, then the rev counter itself is the problem. Not unknown to happen with this particular age of Corrado. I assume the petrol tank & water temp gauges are OK when the rev counter has stopped working.

 

Spoiler down action stuck. Is it stiffer to wind down than up on the manual dog bone handle in the rear hatch? If so, look at the mechanical mechanism itself.

 

Heater blower. Take a look at two things. The bottom motor bearing in the fan unit and also the fan switch on the dash if the Corrado is a face lift version with three round controls. The fan switch contacts sometimes become intermittent. A little gentle bending of the finger contact is needed.

 

ABS can be checked out with VAG-COM on this car and is the quickest way of determining what is upsetting the ABS ECU from the logged fault codes.

 

The wiper problem isn’t obvious.

 

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[bcstudent 0]

RW1...you da' man. I just felt the need to share that.

[G60rob 0]

Thanks for taking the trouble, RW1.

Been away for a few days, and having driven about 800 miles things are a bit clearer.

 

I drove a few hundred miles with the MFA set to read revs. and compared it with the rev counter. The dial reads about 500 rpm slow when it's working, but it's possible I bent the needle's delicate spring one of the many times the module was out.

When it stops working altogether for a while, the MFA readout also goes to zero at the same time. Is this evidence that the fault is not just the rev counter module?

Also, the mpg average from the MFA has gone daft - I wish I was getting 45mpg, but I doubt it's true. Does mpg relate to rpm in some way? All the other MFA functions seem correct.

 

I've had the heater blower out and compared it against a new ECP one, which was actually stiffer to turn than mine, so I greased the bearings as best I could and popped it back in. Seems OK now, so I'll look at the switch if it goes off again. The controls are a four-position rotary switch for speed and two sliders, by the way.

 

At one point I lost the dash warning lights and found that fuse 15 had blown. Replacing it brought back the spoiler, but not the warning lights. Then they came back, then they went again, and so on for a while. Next the starter wouldn't work. At this point I replaced the X-relay with a GSF item and went to Scotland, with everything working apart from the rev counter.

 

The copper tracks in the wiper switch look worn, so I suspect that's the problem there.

 

A couple of people have suggested a faulty ABS wheel sensor, but I'd be surprised if it could be intermittent like this for about a year. A VAG-COM check sounds worth a try.

[Henny 0]

G60rob, the dash fault (clearing/resetting/dropping to 0rpm) sounds like a dodgy earth on the clocks, or possibly what Kongo found out about dead/dying capacitors which cause all sorts of weird and wacky problems with the clocks on G60s... however, the Rev counter fault could well be your loose pin... you need to "tweak" the contacts on the circuit board to make sure that the pin is FIRMLY held by them else it'll flick like you describe (had the same on my speedo!) although, as I mentioned above, the whole dash reset points to either a loose power wire/connector or a dodgy earth... MFA MPG sounds like the pipe onto the back of the clocks is either split, holed or has come loose...

 

Wiper switches can be bought from GSF for not a lot of cash as they're the same as late MKII Golf GTI...

 

The spoiler switch could be something as simple as either the connector onto the motor or the switch has come loose... you'll need to investigate that one a little further to find if there's power getting to the spoiler motor when the switch is pressed to identify where that problem is...

 

ABS faults are a pain in the arse to diagnose on G60s as they don't store the fault codes, so unless the light is ON, you'll not be able to VAG-COM/VW tool it to find out what's wrong with it... I had the same problem with J-DUB for months until a wheel sensor finally died completely...

 

Corradoincidence does sound very likely on this one... I think that the clocks faults are all slightly related to the fact you've had 'em apart "many times" and that they're not really designed to be played with (not knocking you, I've had mine apart too many times to mention too! :oops: :lol: ) so things can get a little looser than they like to be with the contacts in there/on the multiplug...

 

Hope some of this helps... Good luck! 8)

[coolrado 0]

G60rob, the dash fault (clearing/resetting/dropping to 0rpm) sounds like a dodgy earth on the clocks, or possibly what Kongo found out about dead/dying capacitors which cause all sorts of weird and wacky problems with the clocks on G60s... 8)

 

any more info on this capacitor problem henny?

 

i have checked and cleaned every connection i can, and even run a new earth to the clocks, but i still sometimes see the rev counter and speedo dip quite a lot and the clock resets itself most mornings when i start the car.

[dr_mat 0]

ABS faults are a pain in the arse to diagnose on G60s as they don't store the fault codes, so unless the light is ON, you'll not be able to VAG-COM/VW tool it to find out what's wrong with it... I had the same problem with J-DUB for months until a wheel sensor finally died completely...

 

Same with VR6's and crank sensor intermittent faults ...! If you make the mistake of turning the ignition off, it's lost ..

[Henny 0]

the search is your friend... ;)

 

CLICKY!

 

Could also be a problem with the main battery earth... how well does the car start in the morning? If it's hesitant, check the wire from the battery clamp which goes down to the chassis under the battery and then onto the gearbox to see if it's gone green, has a white powdery build up on it or has rusted ends on it... if it has, either clean it up or replace it (about £25 from VW) and see if that helps... ;)

[coolrado 0]

car starts perfectly especially after i nicked the new battery of the works diesel caddy :lol: i have checked all the earth straps and also added some more to make sure so i think that just leaves the clocks now :scratch:

 

cheers for the link :thumbleft:

 

still doesnt appear to be the problem though as my mfa readings seem fine ?

 

ah well i might take the clocks apart and see what happens at the same time as the clocks dip to trace the problem.

[bix 0]

ABS faults are a pain in the arse to diagnose on G60s as they don't store the fault codes, so unless the light is ON, you'll not be able to VAG-COM/VW tool it to find out what's wrong with it... I had the same problem with J-DUB for months until a wheel sensor finally died completely...

 

Mine stores codes?

[RW1 0]

Yeah

ABS can be checked out with VAG-COM on this car and is the quickest way of determining what is upsetting the ABS ECU from the logged fault codes.

 

Assumed this in the earlier note as G60rob has '92 G60 brain power just the last few months of production if I remember rightly. Earlier ones are as Henny says.

 

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[G60rob 0]

Henny, some useful thoughts there, thanks.

I'd wondered about earths, even with the wiper fault. Most of the braided earths in the engine compartment are a bit green or powdery so maybe I should start there. This link seems helpful:

http://www.corrado-club.ca/forum/ultima ... 3;go=newer

 

The battery never gets fully charged, according to my hydrometer, and the cell nearest earth is less charged than the rest.

 

Capacitors: where is the MFA circuit board, shown in Kongo's post?

[RW1 0]

"Capacitors: where is the MFA circuit board, shown in Kongo's post?"

 

Its inside the instrument cluster.

 

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[G60rob 0]

My ECU does store ABS fault codes, nothing else. Had it checked by the auto electrician who found the dissy problem mentioned in my Cutting out thread, and it seems the brake light switch has an intermittent fault which causes the ABS light to come on. Should be easy and cheap to fix, one prob. down, new one just around the corner, I expect!

[steve_16v 0]

new one just around the corner, I expect!

 

more than likely, I think they like having at least one thing that needs fixing! No sooner had I replaced a dodgy shock with coilovers and replaced the knackered battery last week, both the interior blower fan AND the radiator cooling fan have decided to start squealing! :evil:

 

Definately a orradoincidence!

[G60rob 0]

both the interior blower fan AND the radiator cooling fan have decided to start squealing! :evil:

 

Funny you should say that. My radiator fan now has a squeak (3 years old) and the heater blower sometimes comes on slow then gradually speeds up.

 

By the way, fitting a new distributor to cure the cutting out problem also seems to have fixed the rev counter. I suppose the Hall effect sensor must have some connection to the rev counter which is separate from its control over the ignition, because the rev counter could stop working but the engine would keep running.