ford fiesta weird electrical problem

[rob113]

1994 ford fiesta 1790 diesel, 70000miles. Hi everyone, I'm new to forum so can anyone on here help please?

When i turn on the wipers or blower motor, the wipers/blower operate very slowly. the wipers will only turn if you lift them off the screen. and the lights do not work or indicators. The clock also goes off and the temp and fuel gauges go to hot/full reading. the main beam indicator on dash is also on with the small indicators on the side. Thought it might be a short on wiper circuit causing problem, but why does blower do the same thing?? Everything's fine if you don't turn on either blower or wiper. Please help - need car for work Tues, if its raining - can't get there! Thanks in advance.

Bob.

 

[Burnerman]

Hello Bob and welcome
Your car seems to have an earthing fault, most likely I think.....so go over the battery negative connections to the bodyshell and any other connections to the body that you can see.
There will also be a braided strap from the engine and gearbox to the bodyshell too.
Ideally you need perfect cable to metal contact so the connections need undoing, scraping with emery paper and fixing back.
John

 

[Peter.N.]

I would concur with John. Connect a meter between the battery negative connection and a good earth point on the car, turn your wipers on and see if any voltage appears, a few millivolts could be normal but a volt or more means a high resistance connection.

Peter

 

[gregers]

just to add my thoughts
it might be the wiper motors seizing up,hence drawing lots of power???and giving the possible short problem your having?

 

[rob113]

Thanks everyone for your suggestions, I'll give them a go. Just as an after thought, just had the handbrake cable replaced by B.E.T.S - a brake tyre exhaust garage, could they have disturbed anything underneath the car while replacing it? Are there any earth straps in that area. Thanks again.

Rob.

 

[Peter.N.]

I think there is one one from the battery to the engine, although it may be bolted to the gearbox.

If that tests OK it may be a high resistance connection in the battery + circuit.

 

[Burnerman]

I would concur with John. Connect a meter between the battery negative connection and a good earth point on the car, turn your wipers on and see if any voltage appears, a few millivolts could be normal but a volt or more means a high resistance connection.

Peter

One of the original and best tests to do on any vehicle with suspect earths.....and I always forget to do it
John

 

[rob113]

Hi Everyone again,

Thanks for the replies, especially to Peter & John - it's definitely an earth problem. The wiper and blower motor are fitted to a shelf underneath the windscreen. I did as suggested and measured 1.5 to 3.0 volts between battery neg and the wiper motor casing when it was turned on. I've put a temporary wire from batt neg to the motor casing and everything is working fine, (blower works as well), so I can at least use the car in the rain now to get to work! So many thanks for that.

I've looked underneath the car and inside the engine compartment for any straps to the shelf without success. There's one connection from neg to the chassis, so I shorted that out with wire - no difference. When measured with an ohmeter, there's about 1.5 - 2 ohms resistance from neg to wiper casing. Any ideas where to look or what to check, and where on a Ford Fiesta? Any help is greatly appreciated.

One other quick question - where is the oil filter - looked in usual place - front of engine - can't find !

Thanks again John & Peter and everyone who posted - hope you can help on this one again !! I could leave the wire there, but it's not ideal !

 

[Peter.N.]

Hi Bob

Not really familier with your car as I only run old Citroen diesels but I think it would probably be easier to leave your earth strap in situ or you might end up taking the car apart, just run it to the nearest available good earth, which you can check, you obviously know how to use a multimeter.

As regards the filter, I'm sure John will be along shortly to tell you where it is.

Peter