Turned up blower fan, gauges all died!
Turned up blower fan, gauges all died!
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keith2.2

Original Poster:

1,101 posts

225 months

Sunday 8th December 2013
quotequote all
I'm clearly still in the "one thing after another" stage of ownership..

When I has out just now I switched the fans up and the gauges all died, battery light came on full.

The engine was fine and the radio stayed on.

I switched the fan switch off (fans had already stopped) and the battery light went to half brightness, I got some rev counter and speedo movement (but not correct readings).

I didn't want to risk stopping and being stranded so drove home and switched off. It restarted fine - no battery light - but no gauge action or fans either.

The car has a new alternator and battery - the only thing I can think of immediately is a dash or fan fuse? Thought I'd check here before spending the rest of the afternoon with my head in the footwell!

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
Instruments and heater fan are on different fuses.
I suspect your 100 amp fuse may have blown. It can give strange results. Mine caused my speedo to read 55 mph at 4500 rpm in 5th. But the engine ran fine......until the battery ran out.

Do you have a multimeter? I can tell you how to test it.

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
Or you may have blown both fuses......

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
Are you anywhere near me (East Notts)?

keith2.2

Original Poster:

1,101 posts

225 months

Sunday 8th December 2013
quotequote all
I do somewhere!

The 100A is only a few weeks old, too (replaced as part of the last bout of electrical fault finding!) I have some spares though.

If they are separate fuses then yes it rather sound like something else!

I suppose then comes the oh-so-fun task of finding the why..

If you could give a couple of pointers that'd be fab, but if it's something that has been written elsewhere before then a nudge in the right direction is fine!

keith2.2

Original Poster:

1,101 posts

225 months

Sunday 8th December 2013
quotequote all
Unfortunately no, I'm in Herts.

I think I've found your instructions:




Ignition on, don't start the car. 20 volt scale on multimeter. Black lead onto the engine block. Red lead into hole on the top back of the alternator. 12.6 volts, fuse fine. 0 volts, fuse buggered.

If 12.6 volts, while holding multimeter leads in same places, get a passing yokel to start the car. Voltage should change to over 13 volts. If no change, take alternator to auto electrician to prove its faulty.

The fuse is strapped to the underside of the chassis, drivers side, close to where the rear arm of the lower front offside wishbone attaches to the chassis. It is in a black fuse holder case about 35 mm long, in the middle of a thick wire. Replace with a midi fuse off EBay.




So I'll try that first!


QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
That's the ones!
Or if you cannot find the multimeter, just change the 100 amp fuse again if you can remember where it is (under the chassis)
I have had my 100 amp fuse blow twice in 6,000 miles, then not again in 9000 miles. No idea why either time.
They all do that, sir!

The effect of blowing the 100 amp fuse is that the engine is running off battery, not alternator, so anything a bit voltage heavy, or voltage sensitive, can behave oddly.

spend

12,581 posts

281 months

Sunday 8th December 2013
quotequote all
QBee said:
Instruments and heater fan are on different fuses..
EARLY CARS ARE THE SAME FUSE.

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all

He's right. I looked at most of the variants in the Steve Heath bible, but missed that one. Page 241. It's the eighth fuse from the right hand end, shoud be 15 amps.

But I remind you of your own comment - summarized as some activity without the engine running, none with it running.

Could be either therefore.

spend

12,581 posts

281 months

Sunday 8th December 2013
quotequote all
QBee said:
He's right. I looked at most of the variants in the Steve Heath bible, but missed that one. Page 241. It's the eighth fuse from the right hand end, shoud be 15 amps.

But I remind you of your own comment - summarized as some activity without the engine running, none with it running.

Could be either therefore.
EARLY CARS DON'T EVEN HAVE A 100Amp FUSE.

The activity is feedback from the alt field coils, you obviously fail to understand how the alt ign warning light works, so your logic is gobble-de-gook.

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
That's positive. I am learning, thank you, and apologies if I am misleading the OP.
When did they start getting 100 amp fuses?

spend

12,581 posts

281 months

Sunday 8th December 2013
quotequote all
QBee said:
That's positive. I am learning, thank you, and apologies if I am misleading the OP.
When did they start getting 100 amp fuses?
95'ish, hard to tell really as build not totally sequential, and first reg can be completely different from build....

The heater is powered off the dash circuit commonly until the black boxes & ribbon cables were introduced, ie different knob. It doesn't take much (leaves jamming / twigs / crap heater resistor pack) to blow the fuse & typically a jam will blow at any speed and failed resistor pack will blow only at a specific speed.

Sardonicus

19,451 posts

251 months

Sunday 8th December 2013
quotequote all
QBee said:
That's positive. I am learning, thank you, and apologies if I am misleading the OP.
When did they start getting 100 amp fuses?
Around the same time they swapped the battery and fuse box locations approx scratchchin I can vouch for the heater motor fuse taking down the instruments too on a 95 car this as been my 1st and only ever blown fuse in 7+ years of ownership the heater motor had jammed frown

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
keith2.2 said:
I do somewhere!

The 100A is only a few weeks old, too (replaced as part of the last bout of electrical fault finding!) I have some spares though.

.......
Does this make it a later car, or can he have a 100 amp fuse and still have the early heater and instrument combined fuse?

keith2.2

Original Poster:

1,101 posts

225 months

Sunday 8th December 2013
quotequote all
I'll let you know shortly! It's a 94/95 M so right on the changeover.

Edited by keith2.2 on Sunday 8th December 17:26

keith2.2

Original Poster:

1,101 posts

225 months

Sunday 8th December 2013
quotequote all
Righty then;

100A fuse, single blower / instruments fuse!

The later of which had blown (15A)

A jam being the cause would make sense - it was turned up to full, with the control telling it to blow 'down' - but the footwell vent was closed!

I think I need to stop expecting the worst every time something goes wrong - although that's going to t aka some getting used to after my initial induction into ownership!

Thanks for the help everyone. Hopefully the fact I've got old and new electrics will help add some confusion to the mix in future.

Project for winter is fusebox and battery relocation..

QBee

22,490 posts

174 months

Sunday 8th December 2013
quotequote all
Great news - fixed! Sorry i sent you on ared herring, but i have learnt from this too.
One useful thing to have learnt, Keith, is that Sardonicus and Spend know what they are talking about pretty much all the time.