Gremlin in the electrics !!!

Gremlin in the electrics !!!

Author
Discussion

RUSSELLM

6,000 posts

257 months

Thursday 7th May 2020
quotequote all
I will take the fuse out though, and see if it stops the driver’s door lock from working.

I haven’t looked at the TVR’s fuse board before, but where the Two pins of the fuse goes, the cars at work will always have one socket there, it tends to be a little busbar.

Any unused fuses, won’t have the second socket to plug in to. As it’s pointless putting a wire there, that goes to nothing. Saves waste and cost I suppose.

So my rule of thumb normally, is ‘Two sockets = fuse required’

This is TVR though smile



Edited by RUSSELLM on Thursday 7th May 16:01

CerbWill

685 posts

128 months

Thursday 7th May 2020
quotequote all
Gladers01 said:
Cerbwill, looks like you and Russellm have the same type of fuse and relay board, if you can remove fuse 13 and then test by trying the starter button or operating the drivers door lock with the immobiliser enabled, hopefully it wont make a bid for freedom (or start) and this will prove your owners handbook is correct.

Nibors fuse and relay board looks like a different version and fuse 13 is best left out at the moment as per the owners manual as it is somehow back feeding the starter circuit.

Out of interest what rated fuse did you put in and did it blow?

I would also try to take a voltage reading at the new starter relay you fitted or at the starter solenoid coil itself whilst pressing the start button with the immobiliser enabled, if no voltage present its back to the ignition control box or the immobiliser itself.

Good luck and post up later if you have any more info smile




Fuse 13 (20Amp) removed, drivers door still opens from the outside. Starter motor won't work when ignition is on and immobiliser is disarmed.

The OP may have a different fuse board, I'm not sure when the cutover point was. I think 1997 would still have the early type though as the later fuseboard is shared with the Tuscan I believe and that didnt come along until 1999.

The other issue is in his OP nibor states that he removed a blown 20A fuse from Fuse 13, so it must have been doing something. I wonder if nibor has an early fuse box but the manual for a later car.

Penelope Stopit

11,209 posts

119 months

Thursday 7th May 2020
quotequote all
OP

Have you an image of your cars fusebox?

RUSSELLM

6,000 posts

257 months

Thursday 7th May 2020
quotequote all
Just had another look at that pin out list.

It reads to me....

Starter button to ignition control unit 0.5mm

Ignition control to immobiliser ‘in’ 0.5mm

Immobiliser ‘out’ to pin 85 (coil) on starter relay 0.5mm

Pin 87 (normally open) on starter relay to starter motor 3mm


Next mystery is what fuse 13 is doing ? Only thing that would make sense, is for it to be the supply to the common of the relay.

From the OP’s point of view, I’d be double checking you definitely pulled the starter relay. And whilst it’s removed, but with the fuse in place, see if there’s 12v on that pin 87 socket.

Edited by RUSSELLM on Friday 8th May 09:12

Gladers01

896 posts

58 months

Friday 8th May 2020
quotequote all
RUSSELLM said:
Just had another look at that pin out list.

It reads to me....

Starter button to ignition control unit 0.5mm

Ignition control to immobiliser ‘in’ 0.5mm

Immobiliser ‘out’ to pin 85 (coil) on starter relay 0.5mm

Pin 87 (normally open) on starter relay to starter motor 3mm


Next mystery is what fuse 13 is doing ? Only thing that would make sense, is for it to be the supply to the common of the relay.

From the OP’s point of view, I’d be double checking you definitely pulled the starter relay. And whilst it’s removed, but with the fuse in place, see if there’s 12v on that pin 87 socket.

Edited by RUSSELLM on Friday 8th May 09:12
That's about it Russellm, the starter relay M0643 is a single pole normally open type, the coil pins are 85 and 86, the switching is done via pins 30 to 87, so when the coil is energised contact is made between pins 30 to 87 to supply voltage to the starter solenoid coil.

The unlucky for some Fuse 13 (20 amps) is there to protect this circuit should excess current be drawn due to a wiring or starter soleniod coil failure or even a good old fashioned short circuit, would be interesting to know what a good starter solenoid draws current wise, maybe 5 amps?

Have you bypassed your immobiliser on the start circuit only? and added an extra start button from the cabin to starter because of the long cable runs and voltage drop? I think Nibors (blown) fuse has been fitted to prevent the circuit from becoming active.

A piccy of the fuse board would be helpful as there are several versions.

Good luck and post up if there is any more drama, now time for a VE beer



Penelope Stopit

11,209 posts

119 months

Friday 8th May 2020
quotequote all
Guessing you've fixed it by now

If not fixed, is there any chance you can take a photo of the main fusebox and upload it to this topic

Byker28i

69,499 posts

227 months

Sunday 10th May 2020
quotequote all
this is my fuse panel, and handbook entry for a 97 4.2. Fuse 13 is starter and drivers door, fuse 7 is boot and the other door?


Penelope Stopit

11,209 posts

119 months

nibor

Original Poster:

51 posts

266 months

Monday 11th May 2020
quotequote all
Thanks for all the replies I haven't fixed the problem. I have been going through all your comments to find a solution.
Before all this started I had a problem with my immobiliser. I bypassed the immobiliser and alarm system with the help of HF Solutions. The current problem occured a month or so later.

I have checked all the wiring I can see. I also cleaned up the chassis earths and pulled the fuse box out to see if there was any problems on the back of it but there was nothing obvious.

The No 13 fuse that blew was a 20amp. The weird thing is that if I put the fuse in now it doesn't blow. It just keeps turning the car over.

Incidentally my door and electric windows have stopped working !!!!

I have attached my handbook fuse diagram and a picture of my fuse board.
Mine differ from yours.


nibor

Original Poster:

51 posts

266 months

Monday 11th May 2020
quotequote all

RUSSELLM

6,000 posts

257 months

Monday 11th May 2020
quotequote all
My advice, as I don’t trust the TVR book.

You might want to pull the little wire off the back of the starter motor for this, so you can hear what’s happening.

Put fuse 13 in, and listen for the click of a relay. If you hear a click, then we’ve identified your starter relay, and we know the coil is getting a permanent trigger from somewhere.

If there’s no click, it could be that you’ve a relay stuck closed. In which case, pop the fuse in, put your multimeter into that wire you’ve removed from the starter, and you should see a 12v supply on it. Then randomly start pulling relays, until that voltage disappears smile

Edit.... Just noticed that those relay locations, have very little in common with your owners manual biggrin

Second edit.... And those fuse values don’t look like anything you’ve currently got plugged in smile

Edited by RUSSELLM on Monday 11th May 22:59

Byker28i

69,499 posts

227 months

Tuesday 12th May 2020
quotequote all
Early fuse/relay panel like mine Not sure why all the extra relays, they are marked as blank/spare

Edited by Byker28i on Tuesday 12th May 08:38

Penelope Stopit

11,209 posts

119 months

Tuesday 12th May 2020
quotequote all
Byker28i said:
Early fuse/relay panel like mine Not sure why all the extra relays, they are marked as blank/spare

Edited by Byker28i on Tuesday 12th May 08:38
Wonder why?

Byker28i Relay 2 is HRW

nibor Relay 2 is Starter Solenoid

Bristol ave fag

200 posts

82 months

Tuesday 12th May 2020
quotequote all
nibor said:
Does the car turn over at alI now without fuse 13? I wouldn't mess with that circuit, someone obviously has tho, but leave 13 out of it.Maybe let the immobilizer guys have a look at it again.

Penelope Stopit

11,209 posts

119 months

Tuesday 12th May 2020
quotequote all
Bristol ave fag said:
nibor said:
Does the car turn over at alI now without fuse 13? I wouldn't mess with that circuit, someone obviously has tho, but leave 13 out of it.Maybe let the immobilizer guys have a look at it again.
You make a very good point, the wiring may not be standard

The immobiliser relay contacts could be welded together

Not bothered looking at the diagrams as there are enough posters already on the case but........

Have an inkling that the original wiring could have been supply from fuse 13 to starter relay and drivers door as a security measure

Someone attempting to butcher the drivers door wiring for access or to get the car started could possibly blow fuse 13 in the process and prevent the dirty deed

Been wrong before though

Faults a good one



CerbWill

685 posts

128 months

Wednesday 13th May 2020
quotequote all
Well (pretty much) none of the fuses in Nibor's photo match the values of what his manual says should be there. The Horn relay is missing too, according to his diagram. Wonder if the horn works. If it does it further discredits the manual he has.

An update for Nibor on what he's tried so far would be exceptionally helpful so we can rule things in/out. Also it would be useful to know where the manual came from, and confirmation it was the one supplied new with the car. If it's been added on the way then its likely to be total bks.

Gladers01

896 posts

58 months

Wednesday 13th May 2020
quotequote all
Penelope Stopit said:
Bristol ave fag said:
nibor said:
Does the car turn over at alI now without fuse 13? I wouldn't mess with that circuit, someone obviously has tho, but leave 13 out of it.Maybe let the immobilizer guys have a look at it again.
You make a very good point, the wiring may not be standard

The immobiliser relay contacts could be welded together

Not bothered looking at the diagrams as there are enough posters already on the case but........

Have an inkling that the original wiring could have been supply from fuse 13 to starter relay and drivers door as a security measure

Someone attempting to butcher the drivers door wiring for access or to get the car started could possibly blow fuse 13 in the process and prevent the dirty deed

Been wrong before though

Faults a good one
Agree with that Penelope Stopit, you have an appropriate username for this particular problem, think Nibor would prefer to start it at the moment though idea

I get the impression there is a large chunk of this story missing, anyway try putting that relay in socket 9 back to socket 6 for the horn or dispense with it altogether for the time being (possibly there as a previous aftermarket mod?) and check all the fuses are intact some seem to be under rated some slightly over rated, leave Fuse 13 out and try to start up the usual way.

Good luck, post back later with an update and keep at least 2 metres away from any other Cerbs to prevent viral spread smile

nibor

Original Poster:

51 posts

266 months

Wednesday 13th May 2020
quotequote all
I think I need to bin my owners manual.
I have just got the doors and windows working by replacing fuse 6 which is listed as rear window heater,Hazard lamps weeping

Bristol ave fag

200 posts

82 months

Wednesday 13th May 2020
quotequote all
nibor said:
I think I need to bin my owners manual.
I have just got the doors and windows working by replacing fuse 6 which is listed as rear window heater,Hazard lamps weeping
But does fuse 6 knock out hazards etc as well?

CerbWill

685 posts

128 months

Wednesday 13th May 2020
quotequote all
nibor said:
I think I need to bin my owners manual.
I have just got the doors and windows working by replacing fuse 6 which is listed as rear window heater,Hazard lamps weeping
And Fuse 6 is the Door ECU fuse in my manual, same as Byker28i's.

Tried RUSSELLM's idea yet?

RUSSELLM said:
You might want to pull the little wire off the back of the starter motor for this, so you can hear what’s happening.

Put fuse 13 in, and listen for the click of a relay. If you hear a click, then we’ve identified your starter relay, and we know the coil is getting a permanent trigger from somewhere.

If there’s no click, it could be that you’ve a relay stuck closed. In which case, pop the fuse in, put your multimeter into that wire you’ve removed from the starter, and you should see a 12v supply on it. Then randomly start pulling relays, until that voltage disappears smile