Vectra diesel starter relay - where is it?

Vehicle is Vectra Club DTI 16v with 2 litre engine. Manufactured November 2004. Engine is Y20DTH.

Local garage gave me printout from their Autodata system of "Charging & Starting System" circuit diagram.

It shows starter relay is K4.

I have a problem with intermittent failure to start, and would like to identify whether problem is with relay or the starter itself. During failure, turning key to start position produces a click. After trying up to a dozen times in quick succession the starter then spins normally and engine starts.

Please, where is this relay?

I've looked in the fuse box on the front left of the engine bay, adjacent to the battery, but there the relays are labelled as "R" numbers, not "K", and there is no R4, just an empty space with a pcb visible through the holes in the plastic housing where there would be connectors in another variant.

Haynes manual doesn't give any good pictures (and its circuit diagram is different to the one from Autodata - it has the starter relay as K1).

TIA

Reply to
Graham J
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Is it anything like this?

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These things often appear on youtube. Without it, I'd never have found the flasher relay on me sister's Meriva. They stuck it on the bulkhead under the rainwater grill near the windscreen wipers.

Reply to
Etaoin Shrdlu

Thanks,

  1. Left side of trunk - no, only small and large fuses like the video.

  1. Left side of dash - no, only many small fuses and one large (40A) like the video. But there is a nice clip stowed on inside of the cover to use for pulling out fuses!

  2. Under hood, next to battery - no. In mine, the location R4 is south of the red relay in the video, and as in the video it is empty.

Is the Autodata schematic wrong? Seems unlikely since garage had to know the vehicle registration number to get the diagram ...

Any ideas?

TIA

Reply to
Graham J

starter relay is shown as number 6 on the underbonnet fuse/relay plate adjacent to fuse 30, easy way to locate it is to get someone else to operate the switch while you hold each relay

Reply to
Mrcheerful

How do you mean "shown"? Is this on a drawing you have, or on the underside of the fuse cover?

On mine the underside of the fuse cover only shows the fuses; and the relays by "R" number. The one marked R6 is black, half the thickness of the other relays and is positioned the ams as in the video tothe lower right of the square red relay so it is in the right hand column north of the white square relay. But mine doesn't have this white one.

How are these numbers supposed to relate to the Autodata drawing?

Reply to
Graham J

I am going by an earlier autodata than the one the garage used. the illustration shows the starter relay roughly in the middle by fuse 30. Another way to isolate the correct relay is to removeeach one in turn and try the starter, no click means you have got the right one.

Reply to
Mrcheerful

Mrcheerful wrote: [snip]

What you're suggesting is that the schematic from Autodata is untrustworthy. How then do I know that there might not be another relay

- perhaps part of an anti-theft system - that if removed would also stop the starter from operating?

I see that there is a place for blind trial-and-error in faultfinding, but a knowledge of what the circuit should be does help!

Preaumably a Vauxhall service agent would have the correct schematic - or do even they rely on trial-and-error for faultfinding?

My previous experience of the local place is that they would have replaced the whole car piece by piece before finding the actual cause of the problem - whereas an independent chap I went to used his knowledge of the circuit and some test equipment he had made for himself to identify the problem in half a minute. This was an intermittent failure of the connection from the air inlet temperature sensor to the ECU (inside the ECU housing). By that time the Vauxhall agent had replaced the fuel pump and filters; to no effect other than taking money off me, obviously. Sadly that independent chap is no longer trading, having died of old age ...

Reply to
Graham J

It is sometimes (often) quicker to establish a fault by logic than it is by looking in a book, I have often found wiring faults by waggling things around, watching a test meter or listening closely to see what occurs. In your case you say that you can hear the relay click, that might be the remote relay or the relay on the starter, first thing is to establish where the click is coming from.

Reply to
Mrcheerful
[...]

The deficiency is not that of Autodata, rather that manufacturers make changes during production runs that are not well documented. There are also often differences where a particular model is made in more than one location.

A schematic will not help you locate a component; its function is to help you understand how things are inter-connected. They will often just swap bits, especially low-value ones like relays, because it's quicker than fault-finding 'properly'. Welcome to the 21st century!

Always worth trying to find a recommended local independent.

Chris

Reply to
Chris Whelan

An elderly (now dead) mechanic friend of mine specialised in Jaguars, the Jag main dealer used to ring him with problems on older Jags, one day they phoned and asked about an E type that had been brought in for a service and the next morning (still at the garage) now would not start, he asked how far out had they pulled the choke, they actually asked: 'What is a choke?' Young mechanics had never come across carbs with a manual choke. I was surprised that there was not some older foreman mechanic, but apparently even the lead mechanic is just a slightly cleverer youngster these days.

Reply to
Mrcheerful

So far it has generally failed when I'm sitting in the car with the windows & hood closed. The click is audible but faint.

Once it did fail while I stood beside the driver's door reaching in through the window, and with the hood open. The click seemed to come from the area of the starter - but was even then not very loud, not as loud as I would expect. But this is a pre-engaged starter, not one with a Bendix screw.

What I want to do is remove the correct relay and simulate its contacts closing with a piece of wire - with the ignition off; so I can hear what the starter soleniod sounds like. My luck will be that it will always crank when I try this, so I won't be able to confirm that the solenoid/engagement mechanism is actually faulty. But if it seems reliable then I can always get another relay or wire up a switch inside the car ...

If the schematic is untrustworthy this might be difficult, since the power to those contacts might come from another relay.

Reply to
Graham J

But it ought to help you identify it. So if the schematic says K1 and Mr Cheerful says R6 - is that the level of documetation failure you would expect?

Reply to
Graham J

Then you might as well just add in an emergency start wire from the starter's solenoid, hit the other end to battery plus and the starter should turn, if it doesn't then the starter is the fault.

Reply to
Mrcheerful
[...]

That's not a failure of the documentation at all. You are confusing two things; K1 is a schematic designation, and will appear on a circuit diagram, whilst R6 is a physical positional designation.

Chris.

Reply to
Chris Whelan

The thing that just occurred to me is: What state is the battery? A weak battery can give you the symptoms you describe, at 10 years old it may still have the original battery, which may still work but would have lost some capacity, and reduced voltage can give any vehicle problems, particularly vauxhalls.

Reply to
Mrcheerful

Mrcheerful wrote: [snip]

Yes the battery is weak. I was advised this in passing about a month ago while identifying an intermittent fault code (actually the MAF sensor, which causes the dashboard light to come on occasionally).

I asked my garage exactly this question: would a weak battery cause the solenoid to operate but the contacts fail to close; and their answer was no, definitely not. Their suspicion was more that the brushes were not reliably contacting the commutator, and it was chance whether or not the motor would turn. I suppose it's possible that the contacts in the solenoid are dirty?

When it does turn it cranks happily for several seconds before starting; taking longer in warm weather (strange?); it has been generally fairly quick to start in cold weather. The cranking speed is definitely down on what it was several months ago. I had it in mind to replace the battery before winter.

The failures have been intermittent since last Friday. I probably start it 5 or 6 times per day and mostly it starts first try. If it fails to start then up to about 6 more tries have so far been needed. So far it is as likely to fail at any time during the day rather than first time in the morning when everything is a bit cooler, and the battery might have lost some charge overnight.

On one occasion so far I've started it in the evening; it wasn't properly dark but with the headlights on I could see them dip momentarily as I operated the key; and on that occasion the starter didn't engage. So the current drawn by the solenoid was enough for me to notice its effect on the lights; but I was deliberately looking for it. I then turned the lights off for my second try, and of course it cranked immediatley.

I have not replaced the battery in the 3 years I've had the car; so if it is the original it's doing pretty well ...

All the cars I've had previously (which have included Vauxhalls) have normally engaged the starter and tried to crank when the battery was weak - simply cranked too slowly or not for long enough to fire. I've never know a weak battery cause the solenoid to fail to operate properly.

It looks like half a day's work for me to get the starter out (jack up front, remove undertray, remove exhaust - all to gain access to the starter mounting bolts and remove it). I have to work on my driveway: I don't have a hoist or air-driven nut driver. So I'm not keen to take out the starter simply to check.

Reply to
Graham J

Possibly.

I come from an electronics background where for example resistor R1 is called that on the schematic and is labelled as R1 on the printed circuit board.

For ICs it may be that IC 5 is at grid location 66 but that is only because in some designs all ICs are a similar size and fit nicely on a grid.

Many schematics label the component by a grid-like reference as to where it is on the particular page of schematic, and also show the physical location on the PCB.

In your example, in my car the engine bay fusebox all the fuses are have F numbers and all the relays have R numbers. The fuses are roughly in numerical order from front to back, and the relays dot about in no special order. So I rather doubt your statement.

Reply to
Graham J

First get a new correct spec. battery.

Reply to
Mrcheerful

Why?

My background was as an industrial electrician, primarily working with production control systems. I also designed and built in-house control panels. Labelling was most often done in the way you describe; an assigned designation was carried by a device both on a circuit diagram, and at its location.

In the automotive industry it has never been done like that. I suspect that each manufacturer uses their own system whereby a relay that performs a specific function carries a certain designation. For example, K6 might refer to the starter relay on all models. Clearly, component location varies by model, so a different designation is used for that.

I'm not that familiar with GM vehicles, but from experience, and studying Autodata diagrams, I'm pretty sure that's the way Ford does it.

Just be thankful that you are not trying to sort an electrical problem on a Peugeot; I doubt that there are any two vehicles made that are identical WRT designation or wire colour even if assembled next to each other!

Chris

Reply to
Chris Whelan

I bow to your greater experience!

Years ago (1970) I owned an Austin Champ for a few months - each of the wires carried a label explaining its function, and the loom contained spares. Of course that was in the days before relays were used to automate things.

The starter had a Bendix screw and the teeth on the cog for the ring gear were worn, so sometimes it would spin and bounce off the ring gear.

The rear transmission had already failed so it was running on front wheel drive only; in due course the front transmission failed also - while driving up Scotts Hill, Rickmansworth. I gave the vehicle away to a specialist dealer who went to collect it.

Originally it cost me £15 (so about £170 in today's money).

Reply to
Graham J

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