Left fog lights

[VR457]

On a Pfl, which bulb is the left rear fog? Is it the same as the brake light.

My fuse keeps blowing and when it does that, the alternator will not charge above 12.1v. With fuse repalced it charges at 14.2v.

Might be that be battery needs to brought upon to full charge but why would cranking a car blow the fog light fuse????

[Nick Mann]

My best guess would be bad wiring. There is no factory fitted rear foglight, so whatever you have got has been added after. I'd assume from what you are saying that the tailgate brake light element is being used as the foglight - you'd need to work out where the feed is spliced from and to to solve the issue.

[VR457]

Its the engine fuse labelled for left fog light that keeps blowing. I have tried all sorts, disconnecting all the earthing leads, secondary alternator cable, checking rear light bulbs; no matter what i do it is not working. I even tried a 30A fuse but as soon as i reconnect the battery the fuse blows up.

When the fuse was intact the alternator read 14.2v. Now it's back to 12.2v.

I am wondering now if it is all down to the alternator or is it something else?

[VR457]

Update: Left the car disconnected for the last two + weeks. Replaced the fog light fuse, connected the battery, the fuse did not blow again. Started the car, battery recharging at 13.9v. Last two days have been driving around as normal.

I am really confused why this should be the case. I was on the verge of replacing the alternator. With the fog light fuse blown the alternator would not charge above 12v, enough to stop the battery dying but with the fuse in place, its full charge all the way. Like i said, i'm a bit confused why it is like that.

[Wodjno]

Could it be a fault with the Foglight relay ? It could be blowing the fuse, and if when the fuse has blown the relay is stuck in the position of switching the Fog Lights on. Possibly this could cause excessive drain ?

[VR457]

That is a thought. I had briefly considered it but did nothing about it.

There are two relays there which are similar. Can i swap them round? Alternatively, where can i get a spare from / test if it's faulty?

[Nick Mann]

I've got a tin of 2nd hand fuses and relays. I still think it is likely to be an electrical short somewhere.

[exevoowner]

If i remeber when i had my rear panels out there is a relay mounted in there quater by rear light that when you flick the switch for fog light it powers up but i know each importer does things different so could be anywere

[The Vee]

Agree on the wiring / relay ideas. But if the cranking is blowing the fuse, as a precaution I'd be checking battery earth connections to body and engine. If these are poor, return current maybe trying to find alternative routes.
/ one thing that is throwing me out, you say "engine fuse" assuming you mean the fuse box under the bonnet I take it it's not referring to the front fog light?

[VR457]

The engine fuse (100A) was blown about four weeks ago but since replacement has been fine. The Left fog light fuse - 20A (No.4 in the engine fusebay photos) is the problem. With the battery at correct voltage it is ok but with low battery voltage it kept blowing during crank.

This "rear panels out there is a relay mounted in there quater by rear light" - can you give any photos for this Nigel so i can see? This fuse kept blowing even with engine and switch off. All i had to do was touch the negative battery terminal and pop it went.

It seems that with clearing the ecu memory this problem has gone. For now.

[Nick Mann]

I suspect the reset ecu is coincidental. I think it's possible that there is a short circuit somewhere that is better/worse as the temperature changes, or as the weather is drier/wetter. Or leaving it for 2 weeks cause corrosion to reduce the short but time will rub the corrosion away and the problem will reappear.

Just to help others, you can see the fuse in this thread:
http://www.clubvr4.com/forum/showthr...amp-Engine-Bay

[VR457]

Yes, waiting for a bit of time to see if i can trace the wiring for shorting. I did find a stripped wire on the rear light on the bootlid (fog?) with the wire nearly split in two so i fixed that.

Trying to charge the other battery back to life using jump leads, hopefully if it works i will come and see you next week to give said battery and collect some relays.

[Nick Mann]

No probs dude. Next week I will be mostly putting my car back together! It's almost guaranteed I'll be here.