eletrical issue with ignition

[ralph350i]

Hi Guys
Well I have a big problem, the issue the car blowing the ignition fuse when I try to start the it, thus cutting power to the coil, I have traced the wires back from the ignition to the fuse board, then on to the main circuit board and cant find any issues with the wiring, could it be that a faulty relay?

I have also notice I now have no live feed to my fuel pump and the only thing I have really touched is fitted a new starter motor, could it be that the switched wire fitted is on the wrong terminal? I did match them up before fitted the cable and it appears its in the correct place and but if not, could this be the issue, any help appreciate guys as all my hard work feels worthless unless I can get this sorted

Regards


Ralph

[Jack Valiant]

Without knowing what you may have moved or done it is difficult to assist, it sounds like it could be a faulty steering relay though...

[ElvisWedgely]

As with all electrical faults you have to use elimination. If you suspect the starter motor or its wiring, then this has to be eliminated first. disconnect the wiring from the starter and see if the fuse still blows on the ignition start position and so on. If all that is fine, then you have to look elsewhere and eliminate by disconnecting and tracing the wire. Rather a lengthy process but electrical issues normally are. It's probably something simple and you will find it if you persist. A while back I had a charging problem where the alternator would not charge unless excited by a short to the rear of the alternator. The wiring and the alternator was eliminated and working fine. It turned out that some previous owner had changed the ignition bulb and replaced it with the wrong wattage bulb. That's all it was, so simple yet took so much time to detect. Where there is a will, there is a way. Good luck and I hope you find the fault soon.

Tony. TCB.

[ralph350i]

Jack Valiant said:

Without knowing what you may have moved or done it is difficult to assist, it sounds like it could be a faulty steering relay though...

Morning Chris
what happen was that the connection from the ignition (white/red- white wire) had come lose which stopped the car cranking and must have blown the fuse for the ignition coil, I reconnected and the ignition lights came back on and the engine cranked, but every time I turned the key to crank position, it blows the fuse for the ignition coil and after checking the wiring diagram it appears there's a live feed from the relay to the fuel pump, so that's why I have no power there, am thinking the short must have blown the relay, so hopefully I can pick up a new one this morning and try, thanks for your help, cheers, Ralph

[ralph350i]

ElvisWedgely said:

As with all electrical faults you have to use elimination. If you suspect the starter motor or its wiring, then this has to be eliminated first. disconnect the wiring from the starter and see if the fuse still blows on the ignition start position and so on. If all that is fine, then you have to look elsewhere and eliminate by disconnecting and tracing the wire. Rather a lengthy process but electrical issues normally are. It's probably something simple and you will find it if you persist. A while back I had a charging problem where the alternator would not charge unless excited by a short to the rear of the alternator. The wiring and the alternator was eliminated and working fine. It turned out that some previous owner had changed the ignition bulb and replaced it with the wrong wattage bulb. That's all it was, so simple yet took so much time to detect. Where there is a will, there is a way. Good luck and I hope you find the fault soon.

Tony. TCB.

Morning Tony
Thanks very much will give that a try this morning, have already traced all wiring back to the relays which my volt meter confirm no shorts, so am thinking the short, must have blown either the steering replay or both steering and fuel relays, so will replace, will defo check the starter as the car was fine before, many thanks, Ralph

[ralph350i]

Hi Guys
Well I've found the problem but have no idea how to fix, the relay is sending power to both sides of the fuse, thus blowing it, I have changed the relay for a new one I brought and also swapped them around with the other relays but it still does the same, both large brown and small brown/black wires are sending power from the ignition switch when in position 2 to a single large brown wire in the relay, is this correct? as its the only other strange thing I can find, if you could help it would be most appreciated as am pulling what's left off my hair out, cheers Ralph

[Danny Hoffman]

Do you have 2 thin wires connected to your starter motor? If so is it possibe you connected them the wrong way round?

[Wedg1e]

Danny Hoffman said:

Do you have 2 thin wires connected to your starter motor? If so is it possibe you connected them the wrong way round?

The thin wires should have different sized terminals on them so in theory it's not possible to swap them over... and it wouldn't allow the solenoid to pull in if you did.

I'd be looking for a short on the starter high-current cable first (the one from the solenoid to the motor, not the one from the battery, obviously).

The other likely suspect could be the ignition ballast bypass wire having a short... if, say, the ballast bypass wire was on the coil (-) terminal instead of the (+), as you started to crank the igntion amp would fire the coil (-) to earth, effectively shorting the ballast bypass 12v feed straight to earth as well...
of course if the ballast bypass isn't used (it isn't on a lot of V8s) then the foregoing doesn't apply

[ElvisWedgely]

Did the problem start only after fitting the starter motor? Does the fuse blow when ignition is on? or when you actually try to start the car? have you disconnected the solenoid wires and try both ignition position and start position with solenoid disconnected? if problem still exists solenoid and starter is eliminated, if not solenoid and starter are suspects.

Tony. TCB.

[Danny Hoffman]

Wedg1e said:

The thin wires should have different sized terminals on them so in theory it's not possible to swap them over...

I was thinking that maybe the new starter had different types of terminals so Ralph may have had to change the connectors

[ralph350i]

Hi Guys
Thanks for all your replies, am going to go back out and have another look at the starter motor connections, however I did carry out the test with the switched live red/white wire removed and my car only has the live feed from the battery and the switched live from the relay a from what I can remember the car was fine with the old starter fitted, lucky for me I have some spare's so will check

In regards to the ballast I don't recall seeing one, so were would this be positioned please, once again thanks, I,ll take some pictures to see if I can explain a little better, cheers Ralph

[ralph350i]

Hi Guy
Completely disconnect the starter motor and the fuse still blows, so that's out, I hope the picture attached explains a little better the issue I have and here's a colour code for where each wire goes, hope this helps

RED, these are the wires that power the fuse, but both are sending 12v

BROWN, these are the live feeds

YELLOW, this is the starter wire

GREEN, Ignition switch




I can not for the life off me work out why the hell this is doing it, my only thoughts are that the relay is either faultly or somehow power is being feed from the next relay in front off it, as the white wire splits off and jumps into this relay? if you could please help guys, it would be most appreciated as I am at the end of my tether and will end up breaking the bloody thing, cheers Ralph

[Mr Tank]

Hi Ralph

The Red (White) wires go to another relay than the starter.

So what is that relay they for?

I havent got my wireing diagram to hand!

It sounds like someting else is causing the problem.

The relay sounds like its the first place to check, have you changed it!

Andy

[ElvisWedgely]

I am not sure what to advise you at this point but you must work with close reference with the wiring diagram and use elimination to trace the fault. I know this is easier said than done.

If all else fails I have the phone number of a mobile car electrician whom I've used before. I have been told that he has worked with TVR's in the past and knows them well. You could have a word with him. He is reasonably priced and a nice guy. Let me know if you need him.

Tony. TCB.

[The Hatter]

Have you renewed the relays or swapped them around? Not all relays are the same, are you sure you've got the right type in there?

I had the same on my headlights (fuse blowing), turns out I'd swapped in the wrong sort of relay.

http://www.vehicle-wiring-products.eu/VWP-onlinest...

[mrzigazaga]

Hi Ralph...As per phone call here is a diagram of the fuses and relays although somewhat blurry..If you cant read them gis a bell and i will get the magnifying glass out..(Me monicle)..Now put that club hammer down and take a deep breath......And exhale...Ziga


There were two so ive posted both although they look identical..

[Danny Hoffman]

I would be surprised if a faulty relay blew a fuse, it is more likely to fail open circuit as the wire in the windings is very thin.

Does the fuse blow when the relay is removed (prob worth trying all 3)? If not might be worth unplugging items that they feed (AFM, ECU, coil etc)

[ralph350i]

Mr Tank said:

Hi Ralph

The Red (White) wires go to another relay than the starter.

So what is that relay they for?

I havent got my wireing diagram to hand!

It sounds like someting else is causing the problem.

The relay sounds like its the first place to check, have you changed it!

Andy

Hi Andy
The starter wire is not the issue mate, its the two white wires that are connected to the ignition coil fuse, there coloured Red in the picture and are both live causing the fuse to short? cheers, Ralph

[mrzigazaga]

Just to help get a better picture..Ralphs wedge has a carb conversion so no ECU or AFM..Just basic ignition i believe..I suspect an ignition switch could be faulty?..Although im still an electrical dimwit.. ...Ziga

[ralph350i]

ElvisWedgely said:

I am not sure what to advise you at this point but you must work with close reference with the wiring diagram and use elimination to trace the fault. I know this is easier said than done.

If all else fails I have the phone number of a mobile car electrician whom I've used before. I have been told that he has worked with TVR's in the past and knows them well. You could have a word with him. He is reasonably priced and a nice guy. Let me know if you need him.

Tony. TCB.

Hi Tony
I may have to take you up on that offer as I cant get my head around this issue, I,ll let you know asap and thank you very much for your input, Regards, Ralph