Tricky electrical gremlin

[blaze_away]

Prep'd my car for MOT last week, all was good, lights, brakes, wipers, hazards etc

Then on the and night before I jump in start the car engine is fine, turn on the headlights full beam, engine stutters and dies after about 15 seconds. Oh sh&t. Mot cancelled.

On investigation I now find that theres all sorts of electrical oddities happening, like hazards run really slow, left indicators are slow but right is normal.

With ignition on pump primed, but not as vigorous as normal, in conjunction with each flash of the hazards the pump can be heard running a little bit but weakly. you know like flash flash flash with zizz zizz zizz.

We've identified that in conjunction with the hazards a bit of voltage is getting into many of the earth circuits.

Have pulled the entire dash out and the rats nest in pax footwell and can't find any damaged wires.

Unlikely I know but hs anyone had this happen. Its a 98 Chim.

[haaren]

Sounds to me like a earth problem, check all massa points and maybe make an extra earth cable to see if it makes any difference.

[blaze_away]

haaren said:

Sounds to me like a earth problem, check all massa points and maybe make an extra earth cable to see if it makes any difference.

Thanks Ferri

[Belle427]

I would agree, check the battery connections first but then your on to the ground points.

[Loubaruch]

Frank,

Have you checked the 100Amp fuse? I know the local TVR dealer treated it as a service item and changed it yearly.

The earth points are here at the bottom:

https://www.bertram-hill.com/body-lift-single-hand...

Worth checking the ignition switch as well as that would affect most things if faulty easy to bypass!

Paul

Edited by Loubaruch on Saturday 23 August 22:12

[blaze_away]

It was an earth problem.

The giveaway sign was the rear fog light. If we unplugged it the problem went away. Made a new fuel tank earth, direct to the battery in the boot and everything worked as normal........

.however on putting everything back together we now find there is no power getting to the fuel pump, dash heater led's and starter. Oh dear and so it goes on......

[Belle427]

Its well worth checking all the various grounding points really if they have never been done before as a maintenance item.
The cause of many a problem.

[blaze_away]

[quote=Belle427]Its well worth checking all the various grounding points really if they have never been done before as a maintenance item.
The cause of many a problem.[/quot

Great call,

Would love to. Done the two inside on centre tunnel. Haven't been able to locate any thing else. Believe one under the rad (need to remove rad first ?) Do I need to pull fuel tank out to get at the under there ?

[Belle427]

Fuel tank has to be moved out of the way so best to have it fairly empty, as for the front one i think you can reach it with a spanner to tighten but rad would need to come out if you wanted to go deeper ie cleaning up the eyelets.

[Loubaruch]

Frank when you say Fuel tank earth do you mean the main ones on the chassis behind the fuel tank as on my car the fuel tank is not earthed the only connections to the tank are for the fuel levelsender.

[blaze_away]

Belle427 said:

Fuel tank has to be moved out of the way so best to have it fairly empty, as for the front one i think you can reach it with a spanner to tighten but rad would need to come out if you wanted to go deeper ie cleaning up the eyelets.

Okidoki. Rad out then and fuel tank

[blaze_away]

Loubaruch said:

Frank when you say Fuel tank earth do you mean the main ones on the chassis behind the fuel tank as on my car the fuel tank is not earthed the only connections to the tank are for the fuel levelsender.

Good question not sure I can answer as I just don't know how it's earthed down there. Suspect bolt on tank with wire to chassis bolt. Can't fond any clear info on it.
What I can see is the fuel sender has earth attached. A wire from fog light is run there too both those earth's don't go anywhere so tank must be the earth. By deduction tank must be earthed probably at the bottom. Do you have experience?

[PabloGee]

I think you solved this, according to you FB post.
The earth is onto one of the body-to-chassis mounting bolts behind the fuel tank.
Visible behind the fuel tank, and should have some form of insulation between it and the tank.