405 Electrical gremlins - lots of them !

mbunting · Post by **mbunting** » 02 Jan 2008, 12:11

Happy New Year everyone.

I've decided to tackle the many electrical gremlins on my 93 L 405 STI Auto Estate ( with Aircon ).

Here are the issues I'm having.

1) The cooling fans will come on whenever they want, sometimes only for half a second, even when stone cold. The car never overheats though, and this happens even with the A/C off.

2) The headlights - these have a major flicker when the cooling fans kick in.

3) Headlight Levelers - when on the normal level position, both headlights constantly adjust themselves up and down. When the leveller switch is set on anything other than the "normal" level, the problem does not appear.

4) Occasional problems with the starter inhibitor on the gearbox, but I think I'm over these - or they're manageable anyway

So, I've been through the book of lies, and identified some eathing points to check, one of which is on the A-pillar base, but other than checking / cleaning these, any ideas ?

Decca · Post by **Decca** » 05 Jan 2008, 21:42

I initially thought 'earthing problems' as I read your post till I saw you checked an earthing point..
Still ....I would use test leads ( wires with clips on them) and feed a earth to fan relays and headlight assemblies and see how it goes.
Try same with power direct from battery.
I cant see there would be too much wrong, possibly dirty connection somewhere

If the fans are coming on spasmodically.. could be a groggy relay.
I think the 405 has three relays, all identical, maybe able to swap around and see if there is any difference.
Cant remember exactly as brain getting old, but all relays come on for max fan speed ???? and only one operates for half speed ??????
unlikely more than one crook relay if fan coming on flat out. so problem may be elsewhere

good luck

Decca

Post by **admiral51** » 05 Jan 2008, 22:27

Link for the wiring diagram of the fans
http://www.peugeotlogic.com/workshop/ws ... fanop1.htm

both fans should run together slow or fast

i have a 1996 P plate Xantia with A/C and have had similar problems.I cured mine by first cleaning the plug on the thermostat housing that sends info to the bitron unit and then had to rejoin the wires where a previous owner had bodged them
when the contact is broken the fans go into default mode which is spin like hell

mine were spinning when cold and would occasionally cut in and put temp warning lamp on even though gauge was showing 70-80 degrees

the amount of current used when the fans go full chat will cause the headlights to dim for a second.if the fault is intermittent then i would expect lights to flicker quite a lot

this link is for the topic on xantiaclub
http://xantia.ipbfree.com/index.php?showtopic=58

hope this helps

colin

matt · Post by **matt** » 07 Jan 2008, 10:11

There are three relays behind the grill that are worth checking,last time i had problems with the fans,the relay had lost all its spade connectors and fell off!

If you cant find a 405 in the scrappy try a xantia,they are in a similar place i think.

Also there are 2 more earth points worth checking on the inner wings behind the headlights too

Try the Britron sensor like admiral says and the wiring'if you pull the plug off the sensor,both fans should spin full speed.

Ps,if you get stuck for a relay a have a few spare

Brian UK · Post by **Brian UK** » 07 Jan 2008, 16:20

When I had this problem with the fans, I pulled the connector off the Bitron unit, sprayed it with WD40, and put it back on again. Must have just been dirty contacts as the fault never recurred.
AFAIR there is also another earthing multiplug behind the bumper trim, below the fans.

mbunting · Post by **mbunting** » 07 Jan 2008, 21:45

Thanks for everyones replies, I'll outline the issues below. I haven't actually physically checked the earth points yet, just identified them.

1) The headlight levelers have a mind of thier own when set on normal - on any other setting they're fine.

2) The fans have a mind of thier own as well, while the temp gague on the dash always reads correct, the fans will kick in, sometimes less than half a second, the off again. More often than not, when reversing the car onto the drive, the fans will kick in as soon as I pull up to the gate, then then when I turn the car off, the lower speed is active for a while - sometimes as long as 10 minutes, before turning off. This happens whether the A/C is on or off, although having it on tends to reduce the effect of nr 3 below.

3) The current drain of the fans kicking in dims the lights considerably, and it quite often seems like I'm flashing/dipping the lights.

Problem at the moment is that we're down to one car, and the other half is due to pop the sprog in March, so I don't want to "rock the boat" - ie. better the devil you know at the moment, but I may get brave and check a few of the suggested items.

Clogzz · Post by **Clogzz** » 08 Jan 2008, 12:29

Headlights flickering with current drain is the tapered battery terminals working loose.
If the 405 has a multi-plug coming out of the inner wing near the battery, then it may go as here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=22789

mbunting · Post by **mbunting** » 16 Jan 2008, 16:55

Well, the story gets better, then worse !

Last night, before collecting the pregnant wife ( due 7 weeks ), I decided to check the oil level, battery terminals, and fan belt.

The oil needed topping up, done, the negative terminal was loose - tightented, and the belt was ok. Started the car, and drove for about 6 miles - none of the problems in the post occurred ( I would have expected them all to have happened by then ).

As I'm zooming around the roundabout, and lining up with the entry slip, I hear a squeeling, a bang, then some rattling. By this time, I had turned the engine off and parked half way down the slip road to the M1.

Took a look under the hood, the fan belt tensioner pulley was rubbing on the inner wing, the belt was still on the pulley by about 2mm, boy was I glad I turned it off and called the RAC, imagine it taking the cam belt.....

So the car is at the garrage tonight waiting for a tensioner to be delivered tomorrow morning, so we're completely carless at the moment, I'm looking at Toyota's next...

mbunting · Post by **mbunting** » 08 Apr 2008, 12:30

I just thought I'd keep you all updated.

The tensioner wheel was replaced and it passed the MOT.

The headlight level/random issue was the leveller rotary switch in the dash - I've unplugged this and the lights have been fine since.

The fans still have a mind of thier own, I've had the front off and all relays appear to be ok ( dry etc ) with the original covers on !

The sensor half way down the side of the radiator is loose - I plan to replace this as I think this is the cause of the fan issue.

The car sometimes fails to start when very warm ( ie. after sitting for considerable time in traffic ) - I think this is a heat soak problem. Initially I thought it was the starter inhibit on the auto box, but with careful listening, I can hear the relay clicking when I move it from D into N and back again, so it appears to be the starter.

I happened to me last night - I spent about 30 mins in traffic on the M1, about 40 mins later I got to tesco and went to buy a paper, came out and it would not restart for over an hour, absolutely nothing - sometimes you would hear the solenoid engage. After about 80 mins, turned the key, and it burst into life with a nice healthy start, drove home ( about 20 mins with no traffic holdups ), stopped and started it three times without a single issue.

So, since this is going to be the family transport, I'm going to work on the starter next - I'm thinking a heat-soak issue, so will be looking for wiring connections etc..