Battery - Intermittantly dead whilst driving - Help Please

[Fraz-ktf]

Hi.  I've got an annoying issue which first reared it's head 70 miles into a 90 mile trip. Here's what happened, that resulted in the battery being totally dead.
1. Whilst driving, the ABS light started flickering, then after a few miles, stayed on.
2 Then the Air Bag light came on and stayed on then a dashboard "Beep" kept sounding.

At a lay-by, I pulled in, thinking that if I turned off the engine and re-started, it may clear the errors.  To my horror, the battery was totally flat, like wouldn't even crank the motor.  I got a jump start from a kindly passing motorist and continued my journey.

When I arrived, I parked suitably to get a bump-start if needed or a jump but once parked, I turned off the engine again and then tried to start it and it fired up immediately!!! What?

5 hours later, the car started as normal and has been ok until today. . . . .

Started as normal but 30 mins into a journey, the ABS light came on, then the Airbag light and the battery light and the On-Board-Computer went very dim and then kept flashing on and off, with a click from the dashboard.  I turned off all electricals I could and all returned to normal but 10 mins later it all started again.

I managed to complete the journey, to find the battery totally dead again when I got parked.  2 hours later, still dead so I got another jump-start from someone and made the trip home with zero problems and the car re-started just fine once back home (6 miles away)


This is a mystery to me but my limited knowledge makes me think that it's an intermittent Alternator issue?  Could it be a loose wire?  Any suggestions what to look for and where to look for it?

I've done a VAG-COM scan (Before today's re-occurance), cleared the "Low-signal" fault from ABS, HVAC and Aux. Heater and they stayed clear but I bet they are back now.

Any help or wisdom much appreciated.

Thanks

[gregers]

have you look at the fuse box under the bonnet,info on here about it.just to rule it out.

[Chrispb]

I'll second that, check out the two black cables in the battery fuse box.
Check out the link below.

https://www.fordmpv.com/smf2/ford-galaxy-reference-library/battery-junction-boxauxiliary-fuse-box-repair/

[Fraz-ktf]

I'll second that, check out the two black cables in the battery fuse box.
Check out the link below.

https://www.fordmpv.com/smf2/ford-galaxy-reference-library/battery-junction-boxauxiliary-fuse-box-repair/

Greggers & Chrispb . . . you're blummin' Stars! 

I've got some serious meltage to the fusebox cover and the "Top" black wire has almost perished. . . . . . thank goodness I don't need a new alternator!

What is the problem?  Do I have too many electricals running (Heated seats, heated screen, A/C, Headlights, Music etc?)

I'll try the mods in the link you provided

Thanks again you guys 

[Chrispb]

No you don't have to many electrical s running as the wiring in good condition can cope.

Your problem is high resistance caused by oxidation between the crimp terminal and the cable, none of these cables were soldered when originally fitted but because there exposed to the weather corrosion sets in which causes the area of the cable and crimp to get very hot.

There are several ways to repair this depending how bad things have got, most cases you will need a new fuse box and lead but you may be able to repair the lead by fitting a new crimp terminal and soldering on.

If the lead is beyond repair and you replace with a new or s/hand then solder crimp before refitting.

[Fraz-ktf]

Just checked it closely and it looks like I may get away without replacing the whole fuse box but the 50A "Fuse" has melted!

Can you buy these fuses separately?

What are the crimp terminals called with the captive nut? And where can I get one from?

I've cut the cable back to good copper and it will still reach, so that's ok, just need the above and a bit of solder (Hopefully!  )

[Chrispb]

You don't necessarily need a terminal with a captive nut but more importantly it is the right size for the cable and fits the fuse box.
The fuses are available 150amp for the alternator.
You should also consider soldering the other black lead and the short red link cable to the battery

[niall1001]

think iv got a similar problem,2 -3 months ago went to my car and it wouldnt start,wouldnt turn over tho had all the dash lights on then started fine,this went on for a couple of days but couldnt find any issues,i had replaced the aux fuse box earlier in the year and one of the crimp connectors as it had melted,after the innitial issues we went to blackpool(250 mile round trip) and had no issues since,then yesterday started dojng it again,tho this time i noticed the fuel pump wasnt kicking in and wouldnt turn over(like battery was flat) and then after 10 mins of head scratchin turned the key and it fired up with no problems,ran fine,took it for a small drive and stopped started as it should,im at a loss as wat it can be.......

[insanitybeard]

If you've got a 2.3 petrol and it's not been checked/changed already I'd have a look at relay 30, that can cause a non start and is a common fault. There is also (to my knowledge) another relay for the fuel pump which may be worth checking/ renewing at the same time but relay 30 is the usual suspect.

[Chrispb]

If you've got a 2.3 petrol and it's not been checked/changed already I'd have a look at relay 30, that can cause a non start and is a common fault. There is also (to my knowledge) another relay for the fuel pump which may be worth checking/ renewing at the same time but relay 30 is the usual suspect.

Fuel pump relay is 167

[niall1001]

thanx guys,will check relay 30 and 167 at the weekend,its so intermittent its annoying,also will check aux fuse box connections as 1 melted the original so i replaced both fuse box and main feed terminal but not interior connection.

[marinabrid]

is there a way to check this connection before it starts giving trouble ?
mine has the black insulation around it which seems perfect with no cracks in it, but to see what its like underneath would mean cutting into the insulation  which seems a daft idea !
did someone say that it under normal conditions with the car running and electric items turned on  the connector should be cool to touch and if getting hot  thats the clue its time to change it.

[insanitybeard]

If you want to check the state of the connector then you could try-with the engine running obviously- switching on a few things that draw a fair bit of current (e.g, heated front and rear screen, headlamps, heated seats if fitted etc) for a few minutes and checking with your hand if the alternator charging cable/crimp connector in the vicinity of the engine bay fusebox gets hot, if it does then you know there's a problem. Visually, you could disconnect the problem terminals from the engine bay fusebox (safest with the battery disconnected!) and inspect, if they're overheating there will usually be evidence of discolouration (such as darkening from the normal silvery colour) on the metal crimp terminal and fuse link in the fusebox as well as evidence of melting/hardening/cracking of the cable insulation and plastic fusebox housing in the area of the crimp connector.