100 amp fuse vs alternator

[Rooty]

Hi all,

Had a funny experience in the T350 today. Everything was fine, then when i started up at one point i got a fault code of 'power supply.' Thought nothing of it as the voltage was at 14.4 when running, and c.12 engine off.

Stopped at the supermarket. Back in car, wouldn't start. Voltage down to 11. Nipped home to get the power pack, car started. On the drive home (5 minutes) the power gradually decreased until it got to about 9v and couldn't power the car and lights anymore. Managed to crawl home and just as i got it into the garage it died completely. Wouldn't start off the power pack.

I have checked the 125a fuse in the engine bay, seems intact but has a small plastic block in the middle- could it have failed where i can't see it?

There is another 100a fuse link in the drivers footwell isn't there? Does anyone have the exact location as i can't for the life of me find the fecker.

Suppose if it's not the fuse links it'll be the alternator?

Thoughts and help appreciated.

Cheers, James

[LeeT350c]

With your initial power supply code I would say alternator has failed, but fingers crossed!

Cheers, Lee.

[Rooty]

LeeT350c said:

With your initial power supply code I would say alternator has failed, but fingers crossed!

Cheers, Lee.

Fingers crossed indeed, Lee. Nothing like car issues to turn you into a raving alcoholic is there- third beer in about 10 minutes, really hope it's a fuse..

Cheers

[blackiepaul]

the other fuse holder is in the passenger footwell - not the drivers, you can not miss it, just pull back the loose carpet

[Rooty]

blackiepaul said:

the other fuse holder is in the passenger footwell - not the drivers, you can not miss it, just pull back the loose carpet

Sorry Paul, i did mean the passenger footwell. What exactly am i looking for? I can see the immobiliser unit, have uncovered a 50ohm resistor and a few other things but i can't see it..

[extremekiter]

blackiepaul said:

the other fuse holder is in the passenger footwell - not the drivers, you can not miss it, just pull back the loose carpet

Can this one be uprated like the 100amp little sod in engine bay, so to prevent it popping?

Justyn

[shep1001]

Rooty said:

Sorry Paul, i did mean the passenger footwell. What exactly am i looking for? I can see the immobiliser unit, have uncovered a 50ohm resistor and a few other things but i can't see it..

Looks like this against the bulkhead

[Rooty]

shep1001 said:

Looks like this against the bulkhead

Thanks Andy.

Strange- when i opened this up it was a resistor with 50 written on it.. Will check again tomorrow

[shep1001]

Rooty said:

Thanks Andy.

Strange- when i opened this up it was a resistor with 50 written on it.. Will check again tomorrow

Did it look like these?

[Rooty]

shep1001 said:

Did it look like these?

No it was definitely a resistor. The 125amp one in the above picture is like the one under the bonnet- could it fail within the middle plastic bit?

[shep1001]

Rooty said:

No it was definitely a resistor. The 125amp one in the above picture is like the one under the bonnet- could it fail within the middle plastic bit?

Yes. thats where they fail. I have a differnt version of the midi fuse where you can see the centre of it, it looks like a std blade fuse inside.

Shep

Edited by shep1001 on Tuesday 22 February 23:20

[Rooty]

shep1001 said:

Yes. thats where they fail. I have a differnt version of the midi fuse where you can see the centre of it, it looks like a std blade fuse.

Shep

I'll get hold of a 125amp fuse and pop it in, fingers crossed it'll be that..

Cheers Shep

[Rooty]

Right just opened up the 'Midi' 125 amp fuse and it is intact.. Surely can't be fooked if it's still in one piece?

Forgot to add that the dash pod is staying on and making a strange buzzing noise..

[VARLEYHYD]

14.4v is too high

Your alternator diode is likely failed and in doing so allows back feed to dash etc

Fuses probabyl ok

So get alternator checked out

I you are handy you can replace the diode only prior to replacing alt

G

[Rooty]

VARLEYHYD said:

14.4v is too high

Your alternator diode is likely failed and in doing so allows back feed to dash etc

Fuses probabyl ok

So get alternator checked out

I you are handy you can replace the diode only prior to replacing alt

G

Thanks Graham, much appreciated. Is there a guide to replacing the diode, and what will i need?

[Rooty]

Rooty said:

Thanks Graham, much appreciated. Is there a guide to replacing the diode, and what will i need?

Think i'm nearly there with it. Which is the D+ cable where the diode goes inline?

Thanks

[LeeT350c]

Rooty said:

Think i'm nearly there with it. Which is the D+ cable where the diode goes inline?

Thanks

Fitting the diode in-line on the D+ (the small cable on the back of the alternator) will not lower the output voltage of the alternator.

If its reading 14.4v plus the internal diode pack may have failed causing the over charge.

If it has take it off and get it rewound / repaired.

Cheers. Lee.

[VARLEYHYD]

LeeT350c said:

Fitting the diode in-line on the D+ (the small cable on the back of the alternator) will not lower the output voltage of the alternator.

If its reading 14.4v plus the internal diode pack may have failed causing the over charge.

If it has take it off and get it rewound / repaired.

Cheers. Lee.

G