faulty gauges

[michaels]

Hello,

Ok, I know this is supposed to be a home electronics forum but I just can’t find an equivalent forum for car questions… So my apologises if this is against the rules. However, I know you chaps know your stuff. So may be you can help?

My car is currently playing up. It’s an N-reg rover 218 (don’t tease me… it may not be sporty but it does it’s intended job). Recently the fuel and water temperature gauge have been playing up.

They both work fine with the head lights off. However, when I switch the lights on then the fuel gauge gives a constant high reading and the water temp gauge intermittently fluctuates about a much higher reading.

I’m not sure if it’s relevant but with the ignition turned on, but the engine not running, the fuel gauge reads zero with the lights off but max with the lights on.

All very odd. Any help would be appreciated.

 

[mikeh2000]

it could be a earth somewhere as that would cause the current to find the easiest way 'home' and might give funny symptoms

 

[breezer]

I would have to agree, cars have one "earth" connection for several items, i should check the earth connection for your gauges

 

[ban-all-sheds]

I'd agree as well - car electrical systems are horribly interdependent, and when you get faults where thing A works at half spec when you turn on thing B it is almost always an earthing fault.

And they can be a right bvgger to track down.

You will need a wiring diagram, either from a real workshop manual (hard to get) or the appropriate Haynes book.

If you have access at work to a photocopier which can enlarge onto A3, make a few copies, they will be much easier to read, and you can then use those highlighter pens to mark the current paths you should have, and what you seem to have based on the behaviour you are observing.

Good luck.


Regds,
1965 MG Midget-man

 

[il78]

Just to be in the gang...........thats whats i reckon aswell

Regards
Kawasaki ZX6R Not for Midget-Men

 

[breezer]

no you don't

 

[il78]

aahhhhhh please...i do

 

[Scoby_Beasley]

Get a Haynes workshop manual, on the back of the dashboard in my old capri was a capacitor/voltage regulator or something like that. With no fuel in the car and a cold engine, they both read max. In the capri's case it was a matter of removing the clocks unit (not that easy, bloody Fords) and replacing the said gizmo, I can't remember its proper title, too many Guinnesses . It was a simple operation, one screw out and replace, but as I say getting to it was the hardest work but I know from experience a Rover dial box is easy to get out. Rover 216gti was a dream to own and drive especially when you put the sad Rover owner face on at the lights and then burnt the (toy)boy racers off
Best of luck

 

[michaels]

Thanks for all your replies. Not sure I really fancy taking the dash apart and chasing a faulty earth . It may well be a garage job this one. Someone has suggested to me that I should get a heat gun on the relay box in case there is water shorting the circuits after all this rainy weather of late. Might be worth a go.

Thanks for the suggestion Scoby. Someone else mentioned it may be a voltage stabiliser. So that might be worth investigating too. My rover won't beat the boy racers because it's a lumbering oil burner .

Thanks for you suggestions.

 

[breezer]

because it's a lumbering oil burner .

are you sure its a car and not a boiler?

 

[masona]

I think this is a job for Oilman

 

[Scoby_Beasley]

Believe the v/s on a rover is on the bulkhead under the wiper cover, confirmation later.
P.S. the closest earth point is behind the drivers side kick panel (by accelorator pedal) its high up but thats the one to check out.
P.P.S. If you tow a caravan, please ignore any help I suggest

 

[michaels]

You cheeky little scamps! I don't think British Gas would be too impressed if they turned up and I told them to fix my rover fuel gauge. Worth a go may be. They'd probably try to charge me a few hundred quid to flush the radiator!

Scoby.... you get house points and a smiley face! I'll check the earth and stabiliser tonight. Many thanks for your directions. By the way... no caravans. There are some caravan enthusiasts where i work and they scare me. Not as much as Lurchers mind you. Funny looking things .