Help! New battery but car still dead
Discussion
Car refused to crank and I've suspected for a while that the battery was duff so I replaced it with a brand new Exide of correct spec etc. Just fitted it and checked all the connections were clean and tight but no juice is getting through. EVERYTHING IS DEAD! No lights, no ignition, no anything! I know the negative earth is more than sound as I had fitted an extra strap direct to the engine so there must be a break in the positive feed. Any ideas what it could be?
slideways said:
So is the one near the battery to fuse between the battery and alternator? And the one near the alternator is to fuse the alternator to starter?
Mine doesn't have the one by the alternator! Do I really need to replace it?
Yes one in the footwell near the battery. The other under the car near the starter motor on the chassis. This is the one exposed to all the salty road wash unless properly wrapped up in waterproof tape. Mine doesn't have the one by the alternator! Do I really need to replace it?
No,there's no sign of life there but pumps would only kick in if the immobiliser was working. It's a complete electrical shutdown to the fuseboad so nothing works, not even the hazard warning lights! Just had a call-out mechanic on my breakdown insurance who spent about 90 minutes checking it all out and he was baffled too. Reckons it's some sinister alarm/immobiliser fault. The dam things are more trouble than they're worth.
Quietlybonkers said:
The 100 amp fuse under the car is the one that allows the alternator to charge the battery. Without it the car will start and run until the battery runs out. I know. Mine did.....
Mine charges fine? The fuse and holder are no longer there, so must just be wired direct, thats why I asked if I actually need to reinstate it? As its the cause of so many break downsThe immobiliser doesn't cut power to the whole fuseboard, just a few selected circuits (fuel pump, starter etc). I think you need to do some more basic continuity checks.
You say that power is getting through to the starter motor, how do you know? Does it crank over on the ignition key? If so then it sounds like at least that part of the immobiliser is working.
How are you checking that the entire fuseboard is dead? If it is cranking over on the ignition then some power is going through the fuseboard (through the ignition switch)
When you turn on the ignition do any dashboard lights come on?
What about the alarm light on the dash and the immobiliser light on the steering column
What year and model of Griff is it?
You say that power is getting through to the starter motor, how do you know? Does it crank over on the ignition key? If so then it sounds like at least that part of the immobiliser is working.
How are you checking that the entire fuseboard is dead? If it is cranking over on the ignition then some power is going through the fuseboard (through the ignition switch)
When you turn on the ignition do any dashboard lights come on?
What about the alarm light on the dash and the immobiliser light on the steering column
What year and model of Griff is it?
We've tested the engine bay wiring, i.e starter, alternator etc, with a multi-meter and power is there but no power at all to the fuseboard and no ignition lights or any response with or without key fob to trigger the alarm/immobiliser. So I agree, its a continuity issue but assuming for the mo that all the heavy cables are still well connected, its pointing towards a circuit break in the immobiliser. Trouble is,getting it fixed because I don't have a clue about high tech electronics and most auto electrical places don't want to touch specialist cars like these because they know the wiring is a nightmare. Its come at a bad time for me as I have to sell the car (a 1997 500HC) and don't want to fork out £450 for a new kit from Carl Baker.
EGB said:
Can you hear your fuel pump priming. If not, try switching the square relays with a diagonal stripe. If it primes then fuel pump relay in blue socket could be faulty. Also clean the electric contacts on the fuel pump.
Forget this. On all the V8 wiring diagrams I have seen, the relays are latched. The failure of one will affect the other, I know, I have the scars. I would suggest either a different relay or bypass the relay contacts.Edited by EGB on Friday 29th June 20:30
I don't think the immobiliser is the root of your problems. Even if the immobiliser is fried you will still get ignition lights and gauges on the dash working.
I think you need to start at the battery and check continuity all the way to the fusebox, and then the earth return for the fusebox. As you mentioned you had added a new earth to the engine block it's worth mentioning that there are numerous earths and they all need to be good. You have to be methodical and start with the basics.
Before you changed the battery were you getting lights on the dash? I suspect something has become disconnected in the footwell while replacing the battery. With TVR electrics - do not assume anything
The circuits are basically simple, don't forget they were assembled by hand on a board not designed and built by a robot. A decent auto electrician should be able to at least find the cause of this for you. Might be worth putting a post in your local PH regional forum for recommendations on auto electricians in your area.
I think you need to start at the battery and check continuity all the way to the fusebox, and then the earth return for the fusebox. As you mentioned you had added a new earth to the engine block it's worth mentioning that there are numerous earths and they all need to be good. You have to be methodical and start with the basics.
Before you changed the battery were you getting lights on the dash? I suspect something has become disconnected in the footwell while replacing the battery. With TVR electrics - do not assume anything
The circuits are basically simple, don't forget they were assembled by hand on a board not designed and built by a robot. A decent auto electrician should be able to at least find the cause of this for you. Might be worth putting a post in your local PH regional forum for recommendations on auto electricians in your area.
As Colin has said you need to adopt a logical approach. Depending on your car and immobiliser type the circuits immobilised are usually: Starter motor, ignition and petrol pump. Not the main fuse board.
According to the circuit diagram there should be two thick brown +ve feeds from the battery to the fuse block, if either of these have failed it could give your symptoms. As you have been changing things in the battery area highly likely you have disturbed something. I am surprised also that an electrical specialist could not find the problem.
Disconnect your battery and with a multimeter on low Ohms check the continuity of these two back to the battery +Ve.
lead. And make sure they are both making a good contact with the fuse board connectors.
According to the circuit diagram there should be two thick brown +ve feeds from the battery to the fuse block, if either of these have failed it could give your symptoms. As you have been changing things in the battery area highly likely you have disturbed something. I am surprised also that an electrical specialist could not find the problem.
Disconnect your battery and with a multimeter on low Ohms check the continuity of these two back to the battery +Ve.
lead. And make sure they are both making a good contact with the fuse board connectors.
Oldred_V8S said:
EGB said:
Can you hear your fuel pump priming. If not, try switching the square relays with a diagonal stripe. If it primes then fuel pump relay in blue socket could be faulty. Also clean the electric contacts on the fuel pump.
Forget this. On all the V8 wiring diagrams I have seen, the relays are latched. The failure of one will affect the other, I know, I have the scars. I would suggest either a different relay or bypass the relay contacts.Edited by EGB on Friday 29th June 20:30
Loubaruch advice is sound. A live brown wire must feed to fuse box.
Edited by EGB on Saturday 30th June 11:07
Rain stopped play for the mo but have been doing the methodical checks.Yes there are 2 brown wires serving the fuseboard but the positive lead to battery is red which disappears into a loom heading up behind the dashboard so quite where red becomes brown I don't know! BTW, car is a '97 500HC.
Handful said:
Rain stopped play for the mo but have been doing the methodical checks.Yes there are 2 brown wires serving the fuseboard but the positive lead to battery is red which disappears into a loom heading up behind the dashboard so quite where red becomes brown I don't know! BTW, car is a '97 500HC.
The main red goes to the starter, there should a large fuseholder between the battery and fusebox. check that fuse.Gassing Station | Griffith | Top of Page | What's New | My Stuff