Technical 2001 MPI Sei odd headlight problem.

[Stuey3D]

Hi I have a 2001 MPI Seicento which is experiencing and odd issue with the headlights.

I leave the headlights on all the time (bad biker habit as bikes are hardwired on nowadays) as they turn off with the ignition, however lately when I get in the car and turn the ignition on sometimes the drivers side headlight is really dim.
Now sometimes it will fix itself and work perfectly, sometimes it needs to be put to high beam and back again to trigger it, and sometimes the connector under the bonnet needs a wiggle either way it ends up working again and doesn't have a problem for the entire duration of the trip.

Had a look at the connectors and the plastic has melted away on one side so I taped it up to prevent any shorting but it still seems to happen. Oddly enough after I taped the drivers side up, the passenger light also experienced the same symptoms.

If I turn the lights off and on again but don't get out the car and turn the alarm on they come on no problems, the problem seems to occur after I get out and turn the alarm on and walk away. I have tried locking the doors without the alarm and it appears to fix the problem but I haven't tested enough to say this is the case for certain.

I ran a multimeter over the battery as since Summer when we had those floods the alternator seems to make a slight hiss which seems to correspond to the engine speed ie higher revs louder hiss, but everything has worked fine and when I tested today I get a solid 13.8v when just engine running and still 13.8v when all lights fans and heated windows are on so I don't think alternator is the issue.

It could be a battery issue especially as its cold as I only do short journeys now as my commute to work has dropped from 48miles to 3 maybe it's not charging enough, but I don't have a battery charger to charge it up overnight to rule this out.

Anyone with any ideas what this could be, I'm hoping its a simple fix and nothing major needs replacing.

Thanks for looking

stu

 

[fingers99]

It's the connectors. You'll get a set for about a fiver off eBay.

Issue is that a bad contact produces heat, which melts the plastic and softens the actual contacts on the connectors which means they can't conduct properly, and so on.

A smear of silicone grease on the new connectors will cure the problem permanently.

13.8 is a bit low, but noisy alternators can struggle on for a long time. This is a seperate and distinct issue.

 

[rallycinq]

Also check that the earths aren't corroded. as in take them off, clean, abrade, refit, tighten, grease.

Cheers

D

 

[Stuey3D]

It's the connectors. You'll get a set for about a fiver off eBay.

Issue is that a bad contact produces heat, which melts the plastic and softens the actual contacts on the connectors which means they can't conduct properly, and so on.

A smear of silicone grease on the new connectors will cure the problem permanently.

13.8 is a bit low, but noisy alternators can struggle on for a long time. This is a seperate and distinct issue.

Seen some heat resistant ceramic ones 2 for a fiver on the eBay so I shall pick some up when I get paid next week.

Glad it's something easy to fix, also how would you recommend joining them to the existing wiring as these have little tails ready to join, I was thinking a couple of the little terminal blocks to join the wires and then shed loads of insulation tape around it to make it waterproof, unless someone has a better idea.

As for the alternator I thought it was low initially but them when I looked (on this forum I do believe) someone said 13.4-14.4v is a good range for the alternator so I wasn't too worried about the 13.8v. Also bear in mind this was at tick over because as soon as I put revs on I can tell it puts out more power as lights get brighter and no longer dim to the beat of the sub lol.
Would 13.8v cause me problems in the long run? It seems to be solid 13.8 no matter what I threw at it either ticking over or with everything powered up to the max.

Thanks for your advice.

 

[fingers99]

I'd solder them on (cut the existing wires and solder to the new tails and use heatshrink to make the insulation) -- Maplins is a good source for heatshrink, although you can find it online and -- probably at the bigger at bigger Halfords. Terminal blocks are really useful only as a temporary fix to make sure you've connectedted the right wires together -- they won't stand up to those conditions for long. Once you've got the hang of using heatshrink you'll never use sticky tape again!

It'sw the noise rather than the output which is worrying -- like I say, noisy alternators can often struggle on for a long time, but eventually it'll give up the ghost. Should get you through to the spring OK, and in the meantime you can probably find an olde style alternator/battery and starter motor specialist to recon your old one -- often cheaper than an exchange unit.

 

[Pep0]

Hi

Get a spare alternator try a wanted on the forum buy and sell, have it serviced if you are fussy. then swap first time you have inner wheel arch off.

Read the guide on removing alternators first.

The alternator probably has ingested water into its bearings, cause you waded slowly, when the alternator was hot, they will eventually squeal like banshee, so that 70mph in 5th is annoying but still do 13.8v.

Noel

 

[Pep0]

Hi

Get a spare alternator try a wanted on the forum buy and sell, have it serviced if you are fussy. then swap first time you have inner wheel arch off.

Read the guide on removing alternators first.

The alternator probably has ingested water into its bearings, cause you waded slowly, when the alternator was hot, they will eventually squeal like banshee, so that 70mph in 5th is annoying but still do 13.8v.

Noel

 

[Stuey3D]

I really hope the whole alternator is not dieing, I need to rule out the belt first as someone said the hiss could be the belt going plus I have issues with the belt now and again.

I live off a private dirt track and when I first start up and drive everything works however if I go through one of the deeper puddles the lights will dim and the fans will slow down, but when I get to the end of the track and pull onto the road there is a slight squeal which lasts a second or 2 then all power resumes and I have no further issues, because of this I think the belt needs replacing as I don't know when it was last done either.

Plus the hiss is very slight all the time and barely noticeable unless I really rev it hard, also when I initially went through the flood and first started noticing the hissing I dumped an entire can of WD40 into the alternator in the hope that it would stop the hissing, the hissing is quieter now than when it first started.

 

[Stuey3D]

Hmm this gets weirder, I borrowed a battery charger and charged the battery up overnight last night and it hasn't had the headlight problem at all today. It thought about it for a second but came on perfectly with no fuss at all.

I didn't think the battery was too low either as I tested the voltage before I charged it and the battery had a steady 12.8v which I read up is a good voltage for a car battery.

Will still get the new connectors as the old ones have melted on one side as mentioned in opening post but the problem seems to be one of those electrical gremlins you get with a low battery rather than a problem with the connectors.

I will monitor it and see if the problem returns in the meantime.

Thanks for all the advice given, I appreciate it.

 

[Stuey3D]

Spoke too soon, it's come back today. Good job I'm replacing the connectors on payday or after Xmas with delivery times