Thread: Bonnet earth strap and firewall gasket

Originally Posted by Vetcar1

Some advice sought from the collective wisdom of the group please.

1 - I just noticed on my recently purchased '88 Highline that the other end of the earth strap that's attached to the LH bonnet hinge is flapping in the breeze. Can someone please advise where in the engine bay is the correct mounting point for this strap? Also, why is this strap necessary - the under bonnet light works for example without it.

2 - My passenger side front footwell has clearly had a history of getting wet, as evidenced by the Fred Flinstone floor on that side. I think I've located the point of ingress. It appears to be coming in from an 'inspection panel' that's mounted from the outside of the firewall. Looking at it from the engine bay side, the washer bottle does a good job of obscuring it but it's the largish rectangular panel that has a whole lot of relays attached to it. There appears to be a gasket under it, and I assume this is the offending item that's allowing the water in. Has anyone replaced this gasket, and if so, any tips? On an initial look it would appear the gasket would need to be in two pieces (or spilt) in order to be able to feed all the wiring harness through? Thanks.

Can't comment on the earth 'strap" but #2............ that plate on the firewall is where the pedal box on the driver's side would be in a LHD country like the US.

The chassis, diffs and body shells are the same for LH or RH drive AFAIK.

Rust in a footwell is usually from a leaking windscreen seal, then a leaking heater radiator.

I'd be surprised if it's coming from where you think.

cheers, DL

Originally Posted by Vetcar1

Some advice sought from the collective wisdom of the group please.

1 - I just noticed on my recently purchased '88 Highline that the other end of the earth strap that's attached to the LH bonnet hinge is flapping in the breeze. Can someone please advise where in the engine bay is the correct mounting point for this strap? Also, why is this strap necessary - the under bonnet light works for example without it.

2 - My passenger side front footwell has clearly had a history of getting wet, as evidenced by the Fred Flinstone floor on that side. I think I've located the point of ingress. It appears to be coming in from an 'inspection panel' that's mounted from the outside of the firewall. Looking at it from the engine bay side, the washer bottle does a good job of obscuring it but it's the largish rectangular panel that has a whole lot of relays attached to it. There appears to be a gasket under it, and I assume this is the offending item that's allowing the water in. Has anyone replaced this gasket, and if so, any tips? On an initial look it would appear the gasket would need to be in two pieces (or spilt) in order to be able to feed all the wiring harness through? Thanks.

#1 - The Earth strap shouldnt be on the bonnet hinge. The Earth in that location should lead from the Earth stud at the back of the LH head (sitting in the vehicle) to a bolt either on the firewall or on the bracket that mounts the flapper. This Earth is for the EFI and is a bit important.

#2 - IF it is coming from that relay panel, it would be quite rare. You could have a rust hole under the windscreen OR if you have aircon, the water could have been leaking from one of the drain pipes, which often break. You could simply test this by hosing the area and seeing where the water ingresses.

Gents - Thanks for the replies to date.

#1 – Re earth strap…
Konradical – Had a look at the manual for the RRC and in section 76 (Body) it states – “NOTE – An engine ground strap is attached to the forward bolt of the left hand hinge and must be refitted when the hood is re-bolted to the hinges”. However, from what you’re saying, there is an earth stud at the rear of the LH head. This would therefore seem to be the spot where the ‘free’ end of my strap should be attached, ie from the LH hinge to this stud. Is this a dedicated stud that’s obvious to see, or is it an existing bolt that's used for some other bracket/purpose?

#2 – leaking
350RRC – you’re spot on. It would be the pedal box panel for LHD versions. I’ve just had a new screen and rubber fitted so can probably eliminate that source.
Konradical – I tend to agree with you, I can’t see why that panel would leak, although it does have a couple of large grommets through it for wiring to pass, so will investigate that more. I can rule out AC as that system hasn’t run for several years I believe. It was only some recent heavy rain that I noticed the problem. As you suggest, I think I might get the old sheila to train a watering can/hose on the area while I’ve contorted myself inside the car to look up under the dash area.

I'd start looking up the A pillar and to the forward bulkhead scuttle panel under the windscreen.