|
The Clubs Virtual Pub For general chat, so come on in and pull up a chair. |
|
Thread Tools | Display Modes |
21-06-2015, 20:43 | #1 |
Senior Member
Join Date: Jan 2014
Location: Uk
Vehicle: 2004 Terrano 2.7 TDI
Posts: 7,847
|
Noobie fitted a relay to my air horns today
So after installing my air horns and blowing through two fuses in 2 beeps of the horn I was left with little choice than to fit the relay, not having done Anyang like this before it was a bit daunting. It actually turned out to be ok, hardest part was my crappy 6.99 halfords crimping tool that crimps on the piss
Had a few head scratching moments as to which wire where but all wired up (just) Oh yeah and wiring in the positive off the battery and then running it through the body holes and touching the chassis.... Whoops.... Lol... And most importantly, all working, it's loud and comical Pat on the back for myself |
21-06-2015, 21:02 | #2 |
Senior Member
Join Date: Feb 2007
Location: Staffordshire
Vehicle: Maverick Mk I 2.7 TD LWB
Posts: 7,825
|
I hope you have fused it correctly, and used cable with a current carrying capacity greater than the fuse rating, or you will be looking at a possible vehicle fire should there be a fault, which could happen at any time, with or without people in the car, or you could drain the battery, and be unable to start it again.
Just because it is only 12 volts, there is enough energy in the battery to melt and set fire to every loom in the car and then more. So please share you calculations... What size wire are you using, also type, ie No. of strands etc What is the fuse rating? What is the maximum power of the horns hence the maximum current drawn? What rating is the relay you have used? On long cable runs, the voltage drop needs to be calculated, have you considered this and used thicker cables? It's not just the positive feed cable that you need to consider, but also the return wire
__________________
Ford Maverick GLX 1995 2.7TD LWB in illusion silver, 98k miles. Owned since new, for 22 years. Best car I have ever owned. Just wish I could drive it more. |
21-06-2015, 21:54 | #3 |
Senior Member
Join Date: Jan 2014
Location: Uk
Vehicle: 2004 Terrano 2.7 TDI
Posts: 7,847
|
All wires are reasonably short, the 10a standard fuae is still in place, the cable I think was all 17a, the relay was rated at 30a and the relay and the compressor both have individual earth's.
Longest wire is probably positive to relay, still not long. |
21-06-2015, 22:04 | #4 |
Senior Member
Join Date: Jul 2014
Location: Oxfordshire
Vehicle: 3.0Di SVE '05 5 door.
Posts: 1,536
|
As an electrician, and someone who has fitted airhorns to most vehicles I have owned, you should ALWAYS fit aftermarket horns via a relay, even electric, even if you are just sticking another original equipment horn along side.
As Rustic said, cables size must be correct and you MUST fuse the air-horn circuit seperately, the standard circuit fuse covers the other piece of wire leading from fusebox-steering wheel-horn, section. Vehicle fire is worse case scenario, also you could slowly destroy your horn push as the higher current will burn out the contacts. As an aside, when you buy a vehicle don't assume all the fuse are correct rating in the fusebox, my last vehicle T2 '01, nearly went up in smoke as some previous bar-steward had replaced a fuse incorrectly, he had put a 40A in a 10A circuit, had smoke coming out of the dash! When I buy a vehicle now, first job is to check all circuits are fused correctly. Lecture over, now, down to business, Dixie? or La-Cucharacha? |
21-06-2015, 22:04 | #5 |
Senior Member
Join Date: Sep 2010
Location: Mid-Wales
Vehicle: Maverick 2.7 - Patrol 4.2
Posts: 5,645
|
Is that 10a fuse for the standard horn, If so that means just your trigger wire is fused and not the main supply wire
|
21-06-2015, 22:14 | #6 |
Senior Member
Join Date: Jan 2014
Location: Uk
Vehicle: 2004 Terrano 2.7 TDI
Posts: 7,847
|
|
21-06-2015, 22:19 | #7 |
Senior Member
Join Date: Jul 2014
Location: Oxfordshire
Vehicle: 3.0Di SVE '05 5 door.
Posts: 1,536
|
ABSOLUTELY, YES
|
22-06-2015, 07:45 | #8 |
Senior Member
Join Date: Jan 2014
Location: Uk
Vehicle: 2004 Terrano 2.7 TDI
Posts: 7,847
|
|
22-06-2015, 07:46 | #9 |
Senior Member
Join Date: Jan 2014
Location: Uk
Vehicle: 2004 Terrano 2.7 TDI
Posts: 7,847
|
Oh yeah and what fuse?
|
22-06-2015, 08:42 | #10 |
Senior Member
Join Date: Aug 2008
Location: Derby
Vehicle: Freelander & Jeep GC 3.0
Posts: 4,416
|
This thread reminded me of 1966 !
Many years ago I was driving a firms car a (I was in car sales circa 1966) used Sunbeam Rapier through Swadlincote when I decided to switch on the radio .Almost immediately the vehicle filled with smoke.
I pulled to a halt and me & my then girlfriend jumped out of the vehicle fearing it was about to catch fire. I opened the bonnett and could see a glowing red thin cable attached to the battery. Using a bit of rag as a glove I pulled off the wire where it had been attached to the main battery lead. I had a nice burn to my hand but luckily the smoke stopped being produced. The previous owner had fitted a radio without a fuse and connected it directly to the battery using translucent twin flex! The crux of the issue was that it was a positive earth vehicle and someone had fitted a negative earth radio and done a botch of isolating the radio chassis from the vehicle bodywork ! This taught me the consequences of not fusing properly ! |
22-06-2015, 09:02 | #11 |
Senior Member
Join Date: Jul 2014
Location: Oxfordshire
Vehicle: 3.0Di SVE '05 5 door.
Posts: 1,536
|
From the info you gave I assumed that they were some horns you had acquired secondhand or had from a previous vehicle.
If they came in a kit they ought to have had a fuse in with them. Check any instructions to see if they give a fuse ampage rating. What I would do. The other option is to fit a fuse carrier, then fit the lowest fuse you can, i.e. 1 amp. Use the horns like you would normally, if that fuse blows, then fit the next one up. This is NOT an exact science and should be used with care! The official professional advice You SHOULD follow the manufacturers fuse rating. If in doubt consult a professional auto-electrician. Please be careful as I don't what to be reading about your truck going up in smoke. Seriously, if you are not sure, find an auto-electrician. Sorry to be cautious, but, better safe than sorry! |
22-06-2015, 09:22 | #12 | |
Senior Member
Join Date: Feb 2007
Location: Staffordshire
Vehicle: Maverick Mk I 2.7 TD LWB
Posts: 7,825
|
Quote:
This is what my post was all about... You have installed wiring direct to the battery without a protection fuse... Insurance should be null and void if this is found to be the cause of a total loss. I don't know about "putting a spanner in your hands and bad things happen"... it looks like any form of tool. Talking of tools... And the other thing, those cheap plier type crimp tools should be banned, try pulling the wire from the crimp with a reasonable force, it might just pull out. I have the ratchet crimp tools that require a minimum crimping force, before the crimp can be released. Most Auto electricians have been trained in how to use and install the correct cables. Domestic and Commercial electricians also, and they have the kit to test what they have done, do you have a multimeter, if so do you know how to use it? (Properly)... My first career was an Electronic Engineer, and that involved studying at University and passing exams etc, ok the current carrying capacity of cables was a small part of three years study, but it was essential for calculating PCB design and track size etc. Also component selection, plus a lot more. You have to ask yourself... are you competent in vehicle wiring, and the answer is clearly no.
__________________
Ford Maverick GLX 1995 2.7TD LWB in illusion silver, 98k miles. Owned since new, for 22 years. Best car I have ever owned. Just wish I could drive it more. |
|
22-06-2015, 09:24 | #13 | |
Senior Member
Join Date: Feb 2012
Location: South Bucks
Vehicle: Terrano 3.0 SVE 2005
Posts: 3,499
|
Quote:
I had a vision of Alex sat at his desk, studiously raking through volumes of "wire weekly", desperately searching for the information that uncle Rustic was demanding |
|
22-06-2015, 15:09 | #14 |
Senior Member
Join Date: May 2013
Location: Northumberland
Vehicle: Terrano 2.7TDI SE LWB
Posts: 3,604
|
|
22-06-2015, 15:46 | #15 | |
Senior Member
Join Date: Jun 2012
Location: Sevenoaks, Kent
Vehicle: Terrano 2.7TDi SE Touring
Posts: 5,221
|
Quote:
That must be up there as one of the best examples of an oxymoron in use ever. |
|
Thread Tools | |
Display Modes | |
|
|