Electrical problem

[ukMatt]

Hi folks, i have a strange problem with my 96 Chimaera. If i turn the ignition on but dont start her the indicators and fuel guage work fine but the boot release button doesnt work! when i start her the indicators and fuel guage stop working immediately and shes not ticking over right.
all fuses intact.
all started on way home today
any ideas?
thanks in advance Matt

[Penelope Stopit]

This fault could be caused by a bad earth at the rear of the car, I have forgotten where the earth points are, someone should be along shortly with more info

[Steve_D]

Think it is more than just rear earths as that would not effect the idle.
Rear earths are on the nearside upper body/chassis bolt. This is well hidden behind the fuel tank which would have to be drained before it could be shifted.
So for now simply adding an additional earth connection onto the back of one of the light clusters will demonstrate if it is the issue.

I'm more inclined to think the battery is nearly flat having lost its charge from the alternator either from a poor connection or failed 100amp fuse (under the offside engine mount).

If you have a multimeter test the battery then test to see if you have 12v at the large terminal on the alternator.

Steve

[Penelope Stopit]

Steve_D said:

Think it is more than just rear earths as that would not effect the idle.
Rear earths are on the nearside upper body/chassis bolt. This is well hidden behind the fuel tank which would have to be drained before it could be shifted.
So for now simply adding an additional earth connection onto the back of one of the light clusters will demonstrate if it is the issue.

I'm more inclined to think the battery is nearly flat having lost its charge from the alternator either from a poor connection or failed 100amp fuse (under the offside engine mount).

If you have a multimeter test the battery then test to see if you have 12v at the large terminal on the alternator.

Steve

Battery is starting the engine

I was thinking rear earths causing fuel pump pressure problems

[ukMatt]

update, thank you for the replies. there is 12v at alternator, however when i turn ignition on i have no gauges working or the red battery light, when i start her the red battery light comes on and the voltage on the battery reads about half a volt less, so safe to assume its not charging, but ive only just had the alternator changed.

[BIG DUNC]

Check the 100 amp fuse.

You can check the alternator output with a multi meter. Even a new part maybe faulty.

[Steve_D]

If you inspect the 100amp fuse don't just look at it. You need to remove it to be sure as the usual failure mode is not the fuse 'Blowing' it fractures due to vibration and is very difficult to spot just with a visual. Also the fracture can pass a test with a multimeter but not be sound enough to pass a heavy current.

Steve

[ukMatt]

OK thanks will check the 100amp in the morning

[Penelope Stopit]

ukMatt said:

Hi folks, i have a strange problem with my 96 Chimaera. If i turn the ignition on but dont start her the indicators and fuel guage work fine but the boot release button doesnt work! when i start her the indicators and fuel guage stop working immediately and shes not ticking over right.
all fuses intact.
all started on way home today
any ideas?
thanks in advance Matt

ukMatt said:

update, thank you for the replies. there is 12v at alternator, however when i turn ignition on i have no gauges working or the red battery light, when i start her the red battery light comes on and the voltage on the battery reads about half a volt less, so safe to assume its not charging, but ive only just had the alternator changed.

Gauges or no gauges, that is the question

The 100 Amp fuse isn't in the alternator warning light circuit

There is an ignition supply missing at the alternator warning light and this missing supply is very likely the cause of inoperative gauges

The alternator warning light is coming on when you start the engine because voltage is flowing from the alternator warning light terminal and onwards through the dashboard warning light then down to earth through anything that is powered by the same fuse as the warning light

First thing to check is for a blown ignition fuse or missing ignition supply at the ignition fuse/fuses

Edited by Penelope Stopit on Monday 22 April 10:50

[Steve_D]

Penelope Stopit said:

..................First thing to check is for a blown ignition fuse or missing ignition supply at the ignition fuse/fuses..........

That will be fuse 16 which in turn is supplied from relay 5.

Steve

[Penelope Stopit]

Steve_D said:

Penelope Stopit said:

..................First thing to check is for a blown ignition fuse or missing ignition supply at the ignition fuse/fuses..........

That will be fuse 16 which in turn is supplied from relay 5.

Steve

Nice

The OP mentions fuses are ok, Relay 5 could be the problem

[ianwayne]

3 years ago I had a faintly glowing red charging light. Turned out the 100A fuse was cracked (I back up actually removing it to check). Replacing it sorted the issue, so it does affect the warning lamp. Well it did on a 2000 (W reg) Chimaera.

[Steve_D]

ianwayne said:

3 years ago I had a faintly glowing red charging light. Turned out the 100A fuse was cracked (I back up actually removing it to check). Replacing it sorted the issue, so it does affect the warning lamp. Well it did on a 2000 (W reg) Chimaera.

Well in a roundabout way yes it can.
For the lamp to stay out it needs to have the same voltage both sides of it.

Your alternator was charging but not getting through to the battery (dead 100A fuse) It was also supplying better than 12V to the lamp but the other side of the lamp was connected to a battery which was slowly dropping in voltage so the lamp will glow.

Steve

[ukMatt]

update battery fully charged overnight, found ignition fuse had been knocked out of holder slightly replaced it and alternator light went out when started.
fault on indicators and fuel guage still there.
voltage at boot lid button is 8v so i run a direct 12v from battery and boot opened.
after much messing around in footwell when i switch on ignition now and turn off immobiliser car does not start ie no noise from pump or solenoid.
changed the two loose relays in footwell for new ones i had as spares still nothing.
could it be the immobiliser
cheers
Matt

[ukMatt]

Also has anyone got any decent wiring diagrams especially in bypassing the immobiliser

[Steve_D]

For once this will not be an immobiliser issue. The ignition circuit for the ECU, via immobiliser, is direct from the switch via a fuse. The circuits you are having issues with come from the ignition relay R5 (via fuses 15, 16, 17, 18).

Steve

[Loubaruch]

This may help:

http://www.bertram-hill.com/tvr-griffith-ignition....

But be aware that there can be variations between cars especially the circuits that particular fuses supply.

[Steve_D]

No more keyboard guesswork Matt's car came to our workshop.

As we know it had a whole host of random electrical issues which had baffled Matt and the PH collective.
Some of the symptoms.

• Brake lights not working.
• Headlight flash not working.
• Boot not opening.
• Indicators worked but not once engine started.
• Fuel gauge worked but not once engine started.
• No ignition light at key but comes on when engine started.
• Sometimes the fuel pump does not prime. If the fuel pump primes the car will start but if you wait until the prime cycle finishes the engine will not crank….. not even a click from the solenoid. Select fuel pump from RoverGauge and it will crank and run.

First significant clue was testing the brake lights (easiest circuit to get at and test). Multimeter gave 12+ at the switch but jumping across the 2 wires still no brakes lights. A test light on the live wire gave nothing so despite the multimeter seeing 12+ on the switch live wire there was actually no current.
As many of the suspect circuits are fed from the ignition relay this was replaced but without success. I even inserted and removed it many times as I was now suspecting dirty contacts. I even tried bridging the relay without success.
Fitting the Fusebox from my own (project) chim fixed everything. A few days later that ‘box was replaced with another bought by the customer from a salvage yard. The car has now gone home.

I did a post-mortem on the Fusebox and found significant corrosion on the brass contacts primarily on the output of the ignition relay and the 4 fuses it supplies.

I've started a new thread on the fusebox issue as I'm sure it is going to become an issue long term.

It was not obvious at the time but Matt now tells me just about everything on the car is working better. Possible wishful thinking but he is happy.

Steve

Edited by Steve_D on Thursday 16th May 23:32

[QBee]

Nice work Steve, and interesting info for us to store for when it happens to us

[Classic Chim]

Very interesting and so great someone in the trade shares this with us.
If it’s unlikely someone has been going near these contacts do you have an idea as to why they would corrode Steve. Is it just years of damp/ condensation in that area or something else!
Bad contacts are good at causing corrosion of the metal coating which then degrades and compounds the situation, could vibration over the years and contacts jumping be a route cause or am I way off !