GTA Electrics problem

OK all, I have finally sent off my membership application, so am venturing another question.

My GTA is not immaculate or even shiny, but works well, so gets used quite frequently in the dark, the rain, and...

The other night I was out in the dark and the rain, so with everything switched on, which has never been a problem before. I had to go to my son's parent's evening, and he quite likes being collected in the GTA as opposed to the diesel people carriers that arrive for his friends...

However, this time I had a noticeable "hot electrics" smell, although everything still worked, until I went to high-beam; at this point, I lost the lights altogether, along with the dash display. A couple of hasty flicks of the dip-switch got me back to dipped lights and dash illumination. I got home with no further incident, and nothing obviously wrong.

Although I do have lots of manuals etc., I don't seem to have a wiring diagram, and am not brilliant at electrics anyway. Any hints as to where to start looking for the problem..?

Remove the panel just above the fuse box (3 torx screws) and check out the link which is plugged into a fuse holder which is situated on the bottom row, far left. You will have to remove it to check, as it may appear OK, but could be cracked.

had the same thing on my gta last year got in the car at night started the engine but no lights, nothing. turned out to be faulty headlamp relay.one thing i find on these old renaults is the electrical contacts become loose, try squezing them up a bit tighter, sometimes helps.
if you have trouble finding things ask john he has all the electrical diagrams and info.
good luck

Welcome and well done on joining up Luke.
You wont regret it
Hopefully, see you soon.

[Alpineandy]

I don't seem to have a wiring diagram, and am not brilliant at electrics anyway.

There is one on here somewhere. it may well be in the members section.

I'm sure you've checked but it's worth looking at the fuses themselves, too.

When I bought my GTA it was only 6 years old but all the fuses looked well tired, so I replaced the lot. This was based on my old Fuego fuses failing in a similar way to what you've described by breaking through age/fatigue rather than blowing. Hit a bump and half the dashboard and the headlights went out!

Thanks for the help everyone. I have had a chance to look at the car in the dry and warm today, and found the following:

All the fuses seem to be OK, including the ones for the heated rear window which I was suspicious of, as I had been fiddling with it shortly before the problem occurred. However, the fuse holder for the heater fan fuse is a bit cooked-looking, although the fuse itself is OK, and the heater fan works properly. I am not sure which of the relays is the headlight one - they all seem to be ok as far as I can see.

The thing that is looking very cooked, and smells bad (the same smell I noticed when the problem occurred) is plugged into the last, lower socket on the left hand side of the line of relays, under the panel above the fuse box - I assume this is the "link" referred to by John C above. Both it, and it's holder, have clearly over-heated.

Any thoughts as to what might have caused this...? I have disconnected the heated rear window again, as a precaution, as the problem occurred immediately after I had been trying to get that to work... Also, where might I find the wiring diagram mentioned above? Had a nose round, and the "Electrical" section of the manual on here is the one I have, which covers lots of things, but doesn't have a full wiring diagram for the car as far as I can see.

Thanks again for everyone’s help.

Luke

I assume this is the "link" referred to by John C above. Both it, and it's holder, have clearly over-heated.

Yep...thats the link. Did you remove it and check on its condition? This "link" is shown in the circuits as a Relay, however a closer look will show that its contacts are shorted, hence the link. If the link is not cracked in anyway, then weak female connectors in relay socket should be checked, cleaned and retensioned if possible.

but doesn't have a full wiring diagram for the car as far as I can see.

There is not a full diagram of the GTA`s electrics.....only ccts of each function

John

JonC,

As you have some electronics backgound. Can you advise whether there is a method of checking that the speedo pulses received from the sensor in the gearbox are appearing at the large connector LHS of the instrument cluster.

As you know, I've had a issue with the Speedo not functioning. I've checked continunity from the connector behind the rear wheel to the components on the RHS of the cluster. I've also had the PCB on the RHS removed, some points reflowed and checked continunity from connector pins to the various components.
Havent yet removed the sensor itself, but just wondered if there was a method of double checking that the pulse(s) are reaching the connector LHS of the cluster.

Initial thoughts are that a Ohm meter would show a change in resistance, but if the sensor is inductive then would this show up ? My electronics college days seem a bit cloudy !!!

Cheers for any advice.

Regards,
Paul

JonC,

Hi Paul,

I take it you mean me.....spelling not so good at College either
Only joking . It is something I have wondered about for some time, but I have not tried to see if the signal can be checked at that connector as I have not had the need to go looking, and as you know, even to do some testing, it means jacking the back of the Alp up on axel stands in order to have the wheels turning, and also to remove the steering wheel and the Instrument housing....all a lot of hassel if you don`t have a need to check. My thoughts have been to check with an LED, but I don`t think the signal is powerful enough to light it. I think an LED driven by an amplifier would be needed. Clearly an oscilloscope is the answer here, and if you can get hold of a hand held one, then that would do it, and someone in the passanger seat could do the check for you....safely.
I have a couple of Atmo flow meters which I have modified and I can plug an LED into it to see the pulses...even at idle, but the sensors signal is processed in the flow meter its self before it comes out of the unit.
When I wanted to get confirmation that the speed sensor was working, I have used the MPG reading, as that requires the speed sensors output. If the MPG is reasonable, say arounf 25`ish, then the signal is reaching the computer, and if the speedo is not working, then you know its is the board, or the speedo its self. I have posted this before, but at the risk of repeating myself and to save you looking for the info.....if the MPG reading is some what lower than say 25 mpg, moving towards zero, then the speed sensor`s signal is not there or just not getting to the computer, conversely, if the reading goes up towards the 99.9 reading, then the flow signal is missing.
Just for interest, the pic below shows the mod for the Atmo flow meter with the LED plugged in



Hope this helps

John
There is another variable in that the sensor requires a voltage which I think comes from the speedo board its self

Too many Johns on this forum !

Yes, JohnC, sorry.

Well, I normally run the computer in 'diagnostic' mode, so I see a more accurate fuel reading (not fool proof but better than relying on the computed level). In this mode, the readout for MPG varies depending on flow of fuel.
I then clicked the compute reset button and the the readout indicated "------" .
Not sure what info - if any - can be gathered from this.

It just seems such a coincedence that the problems started after the computer illumination lamp failed. Removed cluster to change it and speedo has not worked since.

Pain in the rear !

In this mode, the readout for MPG varies depending on flow of fuel.

Paul, If the mpg is varying up and down then that is a sign that both the speed sensor signal and the fuel flow signal is reaching the computer. Only if one or other of the signals are missing will the reading go either up or down. Its straight foward maths, MPG is miles divided by gallons, therefore if one or other signals stop, the reading will either go up or down depending on which signal has failed.

I then clicked the compute reset button and the the readout indicated "------" .

After you have reset the computer, the car has to travel 400 mtrs before you will see an MPG reading. This is the time to check out the signals. because the MPG is averaged as opposed to instantainous, and the reading will be very sensitive to acceleration and deceleration at this time, which will get less sensitive the greater distance that is travelled.
However if the indicated reading "- - - -" stays like that permanently then neither signals are reaching the computer,......so that would be back to the drawing board then
I know that my method of checking is not from the manual, but I find it extremly useful as all you have to do when driving and the speedo fails, is to press the mode button twice and keep an eye on the MPG reading, but remember if it has been a long time since the computer has been reset, the MPG reading will be insensitive to change, but if a signal is missing then it won`t be too long before the reading moves in one direction or the other.
Hope this helps.

John

Yes John, that's the reason I highlighted the two modes.
I agree, in dianostic mode it simply shows fuel flow and not MPG - how could it with the speedo not working !
In normal mode I just have "------" this after 5 miles of driving stays "------".

So, I dont believe this answers my original question.

Lets try tighning those connector block terminals again ,

in dianostic mode it simply shows fuel flow and not MPG - how could it with the speedo not working !

Paul, having got my spare one out to have a look, it appears that the pulses enter the speedo board and are then split into two circuits, one processes the pulse to a variable voltage to drive the speedo motor, the other amplifies and reshapes the pulses before it then leaves the board to go to the computer. Therefore in answer to your question above, if the part of the circuit that processes the computer pulse is working then the MPG will show, however if the speedo part of the board is u/s then the speedo won`t read.
To answer a previous question, it appears that the sensor is inductive even though it has three wires coming from the sensor, one being a screen which tells me that the actual pulse is very small and the screening is there to protect it against spikes being induced and corrupting the signal. However when it arrives at the boards connector, one of the wires is connected to the screen thus turning it into a two wire sensor. As the sensor is inductive it should not be checked with an ohm meter.

In normal mode I just have "------" this after 5 miles of driving stays "------"

Is this in the "Range", "MPG", "Distance covered" or all three?
The problem here on the Forum is that Fault Finding on these speedos is a process with test after test in order to eliminate different aspects of the fault. I will PM you my phone number and if you wish to have a chat about this, please feel free to call me.

John