Wiring loom / harness

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Ace Dropshot
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Wiring loom / harness

Post by Ace Dropshot »

Time to replace my wiring so my investment doesn't go up in flames on first start! [-o<

My plan is to get a mopar wiring loom / harness kit. I have an auto electrician who can fit it for me.
I'm seeking advise on how many circuits to get and which kit to buy.

Circuits - I have the original (in a mess but makes a rough template for lengths) but I don't know if it had sufficient number in the first place.
For the VF it needs all the standard number (anyone know what that is?) and I here's what I think I should factor in:
- UK indicators
- Electronic ignition? (this was added, non original)
- Extras, for adding additional warning guage etc. in the future (2-3?)
- Anything else I should factor?

Kits - so far I had recommendations for Rebel Wire Kits, Painless and 'Down to Earth Custom & Classic Auto Electrics' kit. All of which seem to have UK supplier availability. However, I've heard that there are varying quality of kits and I should make sure I get a reputable one - whichever that is I don't know!

Thanks
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Aussie Chrysler VF Valiant "Scottish Val"
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ScottyDave
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Re: Wiring loom / harness

Post by ScottyDave »

I made my own using a factory wiring diagram but also factored in the UK indicators etc. Used "vehicle wiring products" up in Derbyshire for most of it, Rockauto for the lamp holders and ebay for odd bits when vwp didn't have what I wanted.
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Derek
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Re: Wiring loom / harness

Post by Derek »

Well done, it looks a lot neater than the old one. Should have no risk of a fire now. =D>
Are we there yet dad ..... 10 to the gallon but worth it.

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Dave999
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Re: Wiring loom / harness

Post by Dave999 »

the only thing that your car had in respect to lighting that is illegal in the UK is the orange reversing lights
i.e both indicators on constantly when you reverse.
so colour and application of light wrong

this could be changed by putting 2 filament bulbs in the indicators at the back allowing them to be on for reversing and pulsing to indicate
provided you swap the bulb holders to tail/brake bulb holders and run a new + feed to this second fliament and allow the circuit to be earthed by the reverse switch at the transmission. which fixes 1 of the wrongnesses.
or add some reversing lights i don't think they are a legal requirment anyway on a car from 1969

the rest followed UK classic car rules

front idicators are kinda wrong its a twin filament bulb in the idicator hoausing that works as an indicator and side light
if you swap to LED has per my post here you can have amber idicator and white side light

https://www.moparuk.com/forums/viewtopi ... &start=150


other than that your orginal loom will have provided enough circuits + one spare for extra things like radio..

mine has 7 fuses
4 in the switched area of the fuse box (fed from igntion switch in all positions from ACC to RUN but off in start)
3 in the ON all the time area of the fuse box (fed from battery) covers interior lights parking lights horns

to be honest i'd be putting the orginal back and replacing what is broken. The dash wiper and lights wireing is pretty complicated
Unless there has been a catestrophic short there is rarely a problem with the middle 95% of the wire. i had great chunks of my loom unwrapped at one point and all of it apart from the 1 section that casued the issue (someone elses bodge) looked as though it was installed yesturday only the exposed ends of wires looked horrible.

i.e you usually need the last 2-6 inches replaced and a new connector, or the thing that it connects to is knackered.

Issues with older wireing are invariably caused by expecting it to carry way more current than it was designed for and that comes about when you fit a massive alternator and a load of new current hungry kit to the car. if you avoid that you avoid the risk.
provided all connectors are tight and clean or new the old wires will do a decent job.

depending on which electronic igntion you go for the wireing as per points is fine,

this provides a switched feed which will be 12 volts with the ballast resistor bypassed or 8 volts with it in circuit
this will come via 2 wires to the underhood section
1 to the ballast or coil from RUN on the switch
and 1 that goes to the starter solenoid and back to the ballast (other/coil end) from start position on the switch
coil negative goes to points or the electronic module although you may have 1 connection for a tacho attached there as well.

The loom for mopar electronic is a self contained lump from the ignition box to the coil and engine side of ballast which replaces the 12/8 volt wire used for points.

I can see why a new loom is attractive and the piece of mind it provides but don't feel its a mandatory expense

standard will have been quite simple so unles you are going for electric fans fuel pump and windows and a big stereo 10 fuse? 12 fuse box should be ample.

if you go for all new

suggest you put headlamps on relays
suggest the power feed from the alternator goes to the starter relay and on to the battery rather than into the car where it usually joins with the battery feed at the ammeter.
remove ammeter and replace with volt meter
add in hazzrard warning lamps
i.e add in a second flasher and a double pole switch for hazzards. power to flasher wire from flasher to switch connected to both pins at the top of switch and 2 seperate wires from the other end of the switch into the left and right idicator circuits (basically anywhere, at the switch in the column or into the feed at the drivers kick panel that goes to the rear is fine all indciators will flash)

remeber the wireing for your brake circuit failure piston thingo, and hand brake on...

there will have been a special fuse wire a fuse-able link, in the feed from alternator to car i.e a sacrifical section in that alternator feed that burns out if something goes wrong best replaced with an automotive circuit breaker or master fuse.

Dave
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colinhammond04
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Re: Wiring loom / harness

Post by colinhammond04 »

What size fuse would you put in between the alternator and the starter relay I’m putting a new 90amp alternator
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Dave999
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Re: Wiring loom / harness

Post by Dave999 »

depends so much on the current consumption of the car

my car has standard wireing and is a basic car no electric windows or seats

if i check the fuse rateings across the fuse box they add up to 80 amps

i have a 36 amp alternator and a big battery with considerably more than 36 amps as its cold cranking amps
in fact a car battery can produce enough current to melt a screw driver.
so those fuses have been selected based on standard sizes, none of the circuits they protect will see the current specified by the fuse rateing in normal use
so i can assume my car consumes something less than 80 amps when all is switched on possibly way less
say max 60 amps

a horn will use 5-7 amps its really just an different style of electric motor
a fan motor can use 15 -25 when it starts but way less when up to speed seconds later
headlamps/lamps decent number of amps dpending on bulb type and number of bulbs

everything on all at once will never happen and the fuses are US fuses so the fuse rateing is a continuouse current rateing not a BLOW rateing like UK/lucas fuses

US fuse 10 amp will blow at say 20 amp
UK fuse 35 amp or of a colur that represents 35 amp will blow at 35 amp but has a continouse rating of say 17 amps

i'd put in something that blows at 80 that way you protect your alternator from trying to stuff 90 amps into a short circuit in that new run of wire
across the car, nromal operation should not be asking for 80 amps if the car is pretty much standard.
Chargeing the battery when it has very low i.e 12.2 Volts won't need 80 amps battery has too much resiatnce for that

if your car is pretty much NOT standard electric water, pump electric fuel pump, electric fans, air horns off a truck, electronicc seats modern retrofit aircon, electric assist on the steering and a huge stereo

use the standard wireing and fuse box for the orginal stuff. keep the new things well away.

and put everything new in via a new fuse box with its own deciated feed from the battery and new wireing of appropriate capcity out to the component and and appropriate fuse for each thing, and then look back to your alternator and its feed to the abttery and adjust based on the consumption of that lot in adition to what was there before.

if the car is standardish a 90 amp alternator might be overkill just depends what you plan in future
but if you have one and you are bypassing the ammeter all is good.

just my veiw based on school/ collage electronics i'm not an auto electrician
others may have a different view

Dave
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colinhammond04
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Re: Wiring loom / harness

Post by colinhammond04 »

Thanks my car is standard no electric seats/windows/fan,led lights all round but has Holley efi and hyperspark ignition with electric fuel pump so I think a 80amp should be fine
Many thanks
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cadboy
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Re: Wiring loom / harness

Post by cadboy »

When I did the change in wiring for my Ammeter, I started with a 40 Amp fuse (from Alternator) and on cars first trip out in day time was fine but as soon as lights came on 40 Amp fuse blew so changed to 50Amps and has been fine since
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Ace Dropshot
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Re: Wiring loom / harness

Post by Ace Dropshot »

thanks Dave. Information gold as usual! :read2:
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