Weird Electrical Glich

[dodgy-alan]

I have a T REG FIESTA 1.25 ZETEC, Most things work as they should, tha car has done 74,000 miles. However over the past 6 months it has devoloped a strange fault. What happens is whenever I turn the blowers on for the heater the fuel gauge works its way down to zero, depending on how much feul is in the car this can take seconds or up to half an hour. Either way the first time it happened I was on the motorway and had to pull over frantically as I was under the impression my fuel tank was draining itself ! needless to say it wasnt and I now am aware of the problem, If i want to know how much petrol I have I just turn the blower of for a few minutes ! However If i switch the A/C on the fuel guage will occasionally come back to life, ditto if I turn the blower on low ! We also found that if i plug my mini fridge into the cigar lighter and turn it on this will also cause the petrol guage to drop! Does anyone have any idea whats happening, I,m assuming its a short circuit somewhere but how the hell can I find out where?

There is also another annoying link between the drivers front window and the rear wiper ! when I lower or raise the window it will get halfway then slow down, as it does so the rear window wiper wags like a happy dogs tail ! It doesnt do it all the time though, about once every dozen or so cycles! Again does anyone have any idea what would cause this?

the faults dont appear to be dangerous as such, Just annoying quirks that we've learnt to live with but I would like to rectify the fault if possible.

If anyone can help I,d love to hear from you.

Many thanks , Alan

[tommy.h]

Hi Alan

don't know if you have it sorted yet,

but it may be worth checking earth point 4 (just below 10)see attached. as this is for instrument panel and radio.

tom

[dodgy-alan]

Thanks mate, I,ll check those points out. until now I had no idea where the earth points were. :D