On ignition my '99 focus dashboard dials (speedo, revs, petrol gauge)
all fly up to max for a couple of seconds than drop back to normal.
This doesn't appear to cause any more problems and it has always
started but it is disconcerting and i guess the focus is trying to tell
me something is wrong.
The only pattern i have noticed is that it happens more on damp
mornings but this is not always the case so i might be seeing causes
that are not there.
anyone else have this problem or know what causes it?
Sadly I don't know the answer, but my '99 has been doing the same thing for
18 months or so. It's rebooting the dash electronics.
It started to happen very occasionally when the weather was cold, and has
gradually got worse. It now does it pretty much all the time. Recently it
caused the odometer to reset to zero also.
I've always thought it was a failing battery; it's the original, but like
yours it continues to start reliably.
I've read that a common cause is a poor connection where the main battery
cable connects to the engine bay fuse box. Purely by coincidence I've just
come in from checking that out! It's a bit of a pig to get to, I removed
the connection, cleaned it up and sprayed it with contact cleaner. I also
cleaned up the main body earth as that was dirty and rusty.
The result? Zilch! It's exactly the same!
Hmmm, Chris has explored the most usual cause for the dash rebooting- as the
cause is it's loosing the constant 12v power supply during igntion on /
engine start which is most likely down to a poor earth or poor supply which
is vanishing under heavy load of the starter etc.
Finding the cause could well be very time consuming. I would also pop down
the interior fuse box, remove the cover and check the 2 main feeds to this
also, and ditto the central timer relay- pull it out and re-seat it.
I've just tried both of those to no effect, although the interior fuse box
didn't have any sort of cover. I had to remove it to get to the connections
on the back. Fun job, huh?
I've put it all back, connections scrupulously clean, fault still there.
I also temporarily used a bit of 6mm cable from the battery pos to the fuse
box feeds. Made no difference, so I'm reasonably sure the fault is not
voltage drop between the battery and fusebox.
Thing is, I drove it 15 miles this am with minimal electrical load. I
checked the battery terminal voltage when I got back and it was 12.44v.
(The meter I used is an industrial Fluke that has been independently
calibrated, so I trust its accuracy.) That does seem a bit low, but yet
it's never failed to start the car even when it's not been used for a week
I'm going to check the battery voltage after it has stood overnight, and if
it seems too low I think I will stick another battery on it anyway. It
can't have much life left in it after nearly 8 years. If I do, I will post
Thanks for the response - i think i'm running the original battery
(haven't checked) so i'll be interested to hear of any improvement. Was
considering changing the battry last winter when the traction control
light started flashing - pulled over and discovered having the front
and rear heated windows and AC on appeared to pull too much juice from
the battery so started to affect all electrical systems. Put this down
to a cold damp start - turned everything off - 'played' with the
traction control on a couple of bends and it was all alright again -
not had that problem since so never got round to investigating further.
The ECU has control of the Heated windows, a/c and alternator regulation,
and will inhibit operation of the 'screens and a/c (boils down to condensor
fans really) if the operating conditions prevent the alternator providing
enough juice to keep the battery voltage up to a set level.
You can simulate this by leaving your lights on for 30mins or so, then
starting the engine and immediately applying main beam and interior fan at
pos 4 and attempting to activate the screens. As long as you discharged the
battery enough you'll find the switches dont work unless you increase the
revs to 1500 or so.
After 15mins of minimal electrical load and an easy cold start you
*definately should have alot more than 12.4v at the battery- I would expect
at least 13v.
You really should pull the surplus charge off the battery for around 1
minute with roughly a 10amp load, then rest for 5mins before measuring it
though for an accurate reading in the absence of a heavy dischrage drop
Had the same issue on my focus when new , ford went through all soughts
of hoops to fix it including replacing the ecu , in the end they
changed the whole display and its been fine ever since , they reckoned
that it could be a faulty battery similar to a cmos battery on a
computer or leaky capacitor
Until I read this thread, I assumed it was normal.
I came searching the newsgroup because my trip odometer occasionally
resets to 0 and I was looking for a resolution to that issue. Now it
appears that the reset is a symptom of a different problem....
Did you resolve it?
I haven't solved the problem on my UK Focus yet.
The next step for me is to replace the battery. It's coming up to eight
years old now, and the terminal voltage after the car has stood all night
is only 12.3 volts. I'm hopeful that it might be the reason I'm having the
Trouble is, it still reliably starts the car so it's hard to justify
There may be some minor differences with US versions so this may not make
perfect sense! Have you checked that all the following are clean and
1. Main earth connections from battery to body.
2. Main feed wire to under-bonnet fuse box. (Tricky to get to!)
3. Main feed wire to interior fuse box.
In each case you should remove the connection, clean it with something
mildly abrasive and the replace it. Sadly it didn't help me, but it is the
common wisdom with this fault to try these things first.
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