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        General >> Give/Need advice to/from others >> Random Electrical Failure
        
(Message started by: Roundozo on Sep 13^th, 2011, 3:51pm)

Title: Random Electrical Failure
Post by Roundozo on Sep 13^th, 2011, 3:51pm

Hi all,

Go a new random problem!! Yay;

So, driving to work the other day I suddenly noticed that the battery light was on. Thought nothing of it as everything worked fine, maybe just a loose connection somewhere as it eventually went out. Today when I got in the car this morning to drive to work I noticed that the ignition lights didn’t come on at all when I turned the key. The car started fine with fuel pump and everything working. This is when I noticed that the speedo, rev counter, fuel gauge, engine temp and indicators had stopped working (makes for an interesting drive to work in rush hour!). I have had a look at the fuse box and they all look fine, no burns anywhere. I have taken them out, given it a good clean and put back and the problem is still there. I then decided to disconnect the battery to allow the ECU to reset (ECU now in for the cosy engine). This hasn’t worked either. I then decided to clean all the connectors to the rear lights as they where intermittent the other day due to poor earthing I think. Still no luck. The normal car headlights and rear lights still work, don’t know about brake lights as I can see themm :P . If I press the hazard lights switch they all work too. I’m stuck for things to look for. ??? ???

The car is a 1978 Mk4 Cortina with a 2.9 24v BOB cossy in. It is using the BOA wiring if that help diagnose this issue.

Going to have to drive home like it tonight as well so wish me luck!!! :-/ :'( :-X

Title: Re: Random Electrical Failure
Post by Highlander on Sep 15^th, 2011, 2:47pm

Are you using the Scorpio fuseboxes?

Sounds like an ignition relay failure, or water in the fusebox?

http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=admin;action=display;num=1281536605;start=0#0

Title: Re: Random Electrical Failure
Post by Roundozo on Sep 15^th, 2011, 3:22pm

That issue ^

No, i'm using the BOA ECU and with the wiring loom fitted to the BOB. The rest of the wiring is the original Cortina wiring. I have had a look at the fuse box and it looks to be ok. I'm going to take it out tonight and give it a good clean. I dont think the ECU is connected to any of the cortina's electricals such as indicators etc so im very confused. Could it be a damaged ECU somehow?

Title: Re: Random Electrical Failure
Post by Mike H on Sep 15^th, 2011, 4:03pm

As it is a "special", can't guess how it is wired up, but as everything else works and it starts up and runs OK etc., sounds to me like a power supply failure to the instrument panel. (?)

Normally, battery light on means it's not charging (possible alternator fault) but don't konw what it would do if inst. panel supply is doing funny things.

Title: Re: Random Electrical Failure
Post by Roundozo on Sep 15^th, 2011, 4:14pm

I've borrowed a multimeter so going to check the alternator tonight. Do you know the voltage that should be coming out of it on the BOB? Have been told by Dave2302 that it could also be a lost an Ignition live feed somewhere so will check that out too.

Title: Re: Random Electrical Failure
Post by Highlander on Sep 15^th, 2011, 4:50pm

Should be showing around 13.5 - 13.8 volts

Title: Re: Random Electrical Failure
Post by Dave2302 on Sep 16^th, 2011, 9:16am

on 09/15/11 at 16:03:35, Mike H wrote:

sounds to me like a power supply failure to the instrument panel. (?)

Normally, battery light on means it's not charging (possible alternator fault) but don't konw what it would do if inst. panel supply is doing funny things.

Yes that's what I think, has lost an Ignition live to the car circuits :)

Battery Light works by bulb having an ignition pos, and other end goes to altenator, which earths it when not charging, then when charging that side of the bulb goes + too so bulb extinguishes...................

Hence if there is no + from dash circuit yes it will glow as there will be a feedback :)

HTH Dave

Title: Re: Random Electrical Failure
Post by Mike H on Sep 16^th, 2011, 9:02pm

Exactement monsieur ;D