205 Stdt Electrical Problem

[Guest The Pirate]

Hi folks,

I hope that someone may be able to throw some light on this problem .

 

I recently bought this STDT , and its almost mint . I brought it back home in daylight (about 100 miles) ....no probs ... did a run to liverpool , about half way there the fans came on ... temperature showing normal , they came off and on for a while then just stayed on . On the way back in the dark the fans came on after a short while , lights dimmed a little then just got dimmer all the way back . Next day ...no start . Called AA man as i was desperate to get back to liverpool , he checked battery .. reasonably ok ....charging .... ok , although the ignition light was dead all the time .

He rigged up an ignition light under the bonnet temporarily and left me with it running .

 

It played up all the way there and back , worse coming back again in the dark , very dim , every time i tried to put lights up even the radio went off !!

Next day ...no starting again . So i took the instrument cluster out ... got the ignition light working , took all the electrical connections that i could get at off the engine scraped , tightened and cleaned . Charged battery overnight . Changed fan switch in rad to to one in my 205 Mi16.

 

Took it for a run and all seemed perfect , and its stayed like that for around 125miles , fans been cutting in from time to time , but always gone off.... today, fans stopped on again with temperature normal , so i stopped in a layby and took out fan relays ...

 

My theory .... either alternator has intermittent non charging probs , or battery has holding probs .

I`ve also cleaned batt terminals and earths to body /engine.

 

I`m puzzled ... can anyone help ?

Cheers,

Pete.

[AndyJ 1]

More likely to be the alternator than the battery, the alternator should be putting out enough amps to run everything even with the battery completely disconnected, shouldnt be causing things to turn themselves off when you put the lights on!

 

Get a multimeter on the alternator and see what its up to. IIRC the MI16 has the same alternator as the TDs? if so swap it over and test it

[Guest The Pirate]

More likely to be the alternator than the battery, the alternator should be putting out enough amps to run everything even with the battery completely disconnected, shouldnt be causing things to turn themselves off when you put the lights on!

 

Get a multimeter on the alternator and see what its up to. IIRC the MI16 has the same alternator as the TDs? if so swap it over and test it

[Guest The Pirate]

Thanks Andy, I`ll try that ... the AA man got a reading of 27 amps .

Why would this cause the fans to come on tho ?

Cheers,

Pete

[AndyJ 1]

Only thing I can think of is either youve got the wrong temperature fan relays (assuming the one you replaced it with isnt broken as well...and that theyre mounted in the right place), or theres a wiring mishap somewhere... theres nothing else connected to the fan circuit to make it go wrong that i can think of.

[AndyJ 1]

Oh does it have air con? I dunno if 205s have a switch which runs the fans when the air con is on, but im sure someone here does!

[Guest The Pirate]

Hi Andy

Its the sender in the rad that I replaced , and it was working on the Mi16 .... Its a puzzle why they should come on , would any drop in voltage trigger the fans to come on, or a surge ?

 

Cheers,

Pete.

[Guest The Pirate]

Oh does it have air con? I dunno if 205s have a switch which runs the fans when the air con is on, but im sure someone here does!

[Guest The Pirate]

Nope , no air con .

[AndyJ 1]

Wouldnt have thought so, ive just dug out the wiring diagram for it... is the bit you replaced the silver cylindrical component that clips to the radiator? Its a temperature sensitive relay... according to this, all it has connected to it is +12v from the battery, the low speed output which goes via a resistor to the radiator fan, and the high speed output which goes directly to the fan, then the fan connects to ground.

 

Of course this is haynes so take with a pinch of salt!

[Guest The Pirate]

Wouldnt have thought so, ive just dug out the wiring diagram for it... is the bit you replaced the silver cylindrical component that clips to the radiator? Its a temperature sensitive relay... according to this, all it has connected to it is +12v from the battery, the low speed output which goes via a resistor to the radiator fan, and the high speed output which goes directly to the fan, then the fan connects to ground.

 

Of course this is haynes so take with a pinch of salt!

 

 

This has a thermostat / sender screwed into the rad , which must switch the fans on via 2 relays mounted to the back of the slam panel in a plastic box , these are the relays I`ve removed to stop the fans.

Maybe I`ll switch the alternators just to see .... i just can`t understand the fans coming on and staying on . At one point they were going off and on on there own with everything turned off !!

[AndyJ 1]

Thinking about it mine has something like that as well... you're not leaking coolant out the top radiator hose and getting the connector wet are you? Might cause the resistance acoss it to change enough to set the fans off.

[Guest The Pirate]

Thinking about it mine has something like that as well... you're not leaking coolant out the top radiator hose and getting the connector wet are you? Might cause the resistance acoss it to change enough to set the fans off.

 

No Andy , i`ve checked that , dry as a bone .... its giving me a headache now ...

[AndyJ 1]

Hehe thats french electrics! ive had plenty of bizarre stuff go wrong with mine that "couldnt possibly be happening" and turned out to be a loose nut on the starter motor... just a case of trace everything til you find something wrong really.

[Guest The Pirate]

Hehe thats french electrics! ive had plenty of bizarre stuff go wrong with mine that "couldnt possibly be happening" and turned out to be a loose nut on the starter motor... just a case of trace everything til you find something wrong really.

 

 

The charging light is going out , but i suppose thats no indidcation of the actual output .......anybody else any ideas ??

[jimistdt 1]

Have you checked the earths to the body? Seems like alot of things to go dodgy at once.

[Guest The Pirate]

Have you checked the earths to the body? Seems like alot of things to go dodgy at once.

 

Thanks Jimi,

I`ve checked and cleaned the earth cables .... its a puzzler .

Cheers,

Pete.

[Guest The Pirate]

Well .................. i removed the fan relays and have done 225 miles with no probs whatsoever , so its obiously a faulty sender/switch or faulty relays , whatever, the fault lies in that circuit , its not budging from a third of the way up the temp guage ....so it can stay as it is for a while and I`ll replace the lot to be sure . Thanks for the replies . If any body has replacement parts for sale ....i`m interested .

Pete.