reasons not to use existing grommet?

Have an audio installer shop that will not use existing grommet for the power wire and insist on creating their own and placing a grommet. They said that sticking a wire through an existing one with bunch wire can possibly cause damage to them and the cars' eletrical system. Are they feeding me a load of crap??

i have seen cases where installers have penetrated insulation on multiple wires when going through an existing grommet.  I have actually seen a car try to start.  However, a confident and competent installer will know how to penetrate the grommet without damaging the harness.  If they do not want to do it, DO NOT MAKE THEM.  They will be dying to say I told you so.  I personally think it is much safer to use an existing grommet.  I have seen more problems with drilling holes in firewalls.  If you insist on using this shop, You could penetrate the grommet yourself and get the wire through yourself.

I 2nd that...How much more are they charging you...?M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

tommy... wrote: I 2nd that...How much more are they charging you...?

They're not charging me extra. Its their standard procedure for all installs because something happened two years ago where their insurance pay a lot of money for damages. They will not install it any other way. These guy do decent job with good prices (not the cheapest). I was just wandering if I should just find another shop as i hate doing "permenant" mods to a brand new car (such as drilling holes), but if its a safer way, then so be it.

tommy... wrote: Yeah...Well if your planning on keeping the car for awhile...There might be some pre-mature rusting...Normally when we do drill a hole...We just make sure it is weather/water proofed...Some tar,silicone,etc...I cant say i recall  seeing one rusted...And there has been repeat customers over the years...I Have seen the hole rusted in other vehicles that wasnt treated...! Also saw a guy cut a bunch of wires while going through a grommet...So...Worst case...you said they have insurance right...?

Yes, they have insurance...according to them lol. So, I guess just drilling a hole and sticking the grommet around the edges don't really protect it from rust?

Either method is fine if done properly. If a hole is driled we grommet the firewall with marine style grommet that seals to the wire and bolts through the firewall. Then we seal around it with 3m strip caulk. Never had an issue with this method and we install in an area that sees alot of weather.

You could ask them if they paint the hole, always did that in the old days when installing antennae.