It's Time to Re-wire my Lights! (and my Wipers)

[OldCarNewTricks]

Hello,

I am currently working on getting my 242 running. The injection and ignition wiring has mostly all been replaced, from the looks of it. However, the front lights have not been so lucky. There is a mess of bare wires on the front passenger side of the engine bay. This does include the wiper-washer pump and horn wiring.

My wipers are always on on the lowest setting, whenever the car is turned on, so I'm still trying to figure this issue out.

I was thinking about buying a package of 3m assorted color electrical tape, and then buy some good quality TXL wire in basic colors. Then I can just use the colored tape to mark the wires for future reference for cost savings.

What gauge wiring is best for the different lights? 14ga for head lamps, 16ga for markers, turn signals, horn and washer pump?

I think I will also take the extra step to add relays for the head lamps, and also add a relay for the fog lamps I intend to add in the future. It's usually recommended to place relays close to the source (battery) and run the better part of wiring to the trigger (3 stage switch), is this correct?

If anyone has any tips, tricks or experience, I'd love to hear what you have to say on this matter.

Thanks!

[nel621]

Do yourself and the next guy a favor and use the correct COLOR of wire when you make your new harness. It helps later on when tracing something using the factory wire diagram. Years ago I had to make an engine harness for an 80 262c. The only color I didn't have at the time was yellow with a blue tracer. Solved this issue by running a yellow wire over a blue permanent marker. Worked like a charm. Too a few hours to make a totally new harness.

[dl242gt]

I second the suggestion on getting colored wire to help identify the circuits later on. Another nice upgrade is to buy a premade harness for the headlights. They are usually about $45 or so on summit racing for a decent quality one. Get a good stripper crimper it'll help make the splices and connections easier to make.

[patrickstar]

I just rewired my headlights (and the rest of the chassis harness...) in my LS swapped 242. It was actually pretty easy once I got into it, especially since I didn't use any factory stuff. I also converted my headlights to H1/H4.



Glass H1/H4 headlights installed



10AWG power supply from alternator, two 30a fuses inline.



Mounted the relays next to the radiator. 14awg wiring for the headlights which was overkill



Blue is high beam, white is low beam



The wiring diagram I came up with. My situation is a little different because I was using an ARC 8000 PDM to complete the relay trigger circuit, and the switch is grounded.

[OldCarNewTricks]

Excellent suggestions! I will be sure to get multi colored wires. May not 100% match factory colors, but getting multiple wire colors is definitely worth it, as it sounds.

I did not know they did pre-made universal relay/wire harnesses. That will make it exceptionally easier if I choose to go that route. I will do more research on this, as it seems it is very fairly priced. I have some good quality tools in the garage, as my main project car is an LS swap Camaro, and that has required a lot of tool purchases (expensive!).

patrickstar, awesome! Thanks so much for the examples! You went above and beyond! That's some hefty stuff that will last for a long time.

[patrickstar]

Originally Posted by OldCarNewTricks

Excellent suggestions! I will be sure to get multi colored wires. May not 100% match factory colors, but getting multiple wire colors is definitely worth it, as it sounds.

I did not know they did pre-made universal relay/wire harnesses. That will make it exceptionally easier if I choose to go that route. I will do more research on this, as it seems it is very fairly priced. I have some good quality tools in the garage, as my main project car is an LS swap Camaro, and that has required a lot of tool purchases (expensive!).

patrickstar, awesome! Thanks so much for the examples! You went above and beyond! That's some hefty stuff that will last for a long time.

I was going for super heavy duty. I looked into the universal headlight harnesses but heard issues with quality control, and figured that if I was going to be cutting and splicing to make it all fit nicely, I might as well do it from scratch.

I picked up a metric ****-ton of GXL wire from a seller on eBay. Each bundle has 8 25ft sections in individual colors, which was enough for me. I also picked up a 1000 piece set of assorted uninsulated terminals which has made it very easy. I think I have enough supplies to wire 2-3 more 240s now...

[OldCarNewTricks]

Originally Posted by patrickstar

I was going for super heavy duty. I looked into the universal headlight harnesses but heard issues with quality control, and figured that if I was going to be cutting and splicing to make it all fit nicely, I might as well do it from scratch.

I picked up a metric ****-ton of GXL wire from a seller on eBay. Each bundle has 8 25ft sections in individual colors, which was enough for me. I also picked up a 1000 piece set of assorted uninsulated terminals which has made it very easy. I think I have enough supplies to wire 2-3 more 240s now...

That's all very true. Looks like the uni. kits also use plastic connectors for the headlights. I might piece my own together, as well. Then I can use ceramic connectors, instead. I bought rolls of GXL wire off eBay for my Camaro, as well. There seems to be fantastic deals around that beat out Painless Wiring's absurd wire prices.

You used the ARC as the positive supply, with the switch being ground. I'm thinking to do similar and wire my switch to handle ground only, as that makes wiring a fair bit easier, and less positive wire routed through the car, correct? Only issue is that would make the bulb out light on my dash permanent, and that would be annoying.

[patrickstar]

Originally Posted by OldCarNewTricks

You used the ARC as the positive supply, with the switch being ground. I'm thinking to do similar and wire my switch to handle ground only, as that makes wiring a fair bit easier, and less positive wire routed through the car, correct? Only issue is that would make the bulb out light on my dash permanent, and that would be annoying.

It works incredibly well actually, I had a lot of people tell me it was overly complicated (it is, but I'm not worried). I was also interested in having less positive wire running in the cabin. I can't comment on the bulb out light, since I don't have a factory cluster anymore

[OldCarNewTricks]

Originally Posted by patrickstar

It works incredibly well actually, I had a lot of people tell me it was overly complicated (it is, but I'm not worried). I was also interested in having less positive wire running in the cabin. I can't comment on the bulb out light, since I don't have a factory cluster anymore

What cluster are you using now? Custom made ABS panel with aftermarket gauges? I find some of the old electronics to be an annoyance. They worked extremely well at time of manufacture, but 30+ years has a negative effect on their ability to function as they should.

[patrickstar]

Originally Posted by OldCarNewTricks

What cluster are you using now? Custom made ABS panel with aftermarket gauges? I find some of the old electronics to be an annoyance. They worked extremely well at time of manufacture, but 30+ years has a negative effect on their ability to function as they should.

As of right now, just the Holley Terminator X 3.5" LCD. I'll install an aftermarket tachometer eventually, or considering a Holley 6.86" screen.

I was silly and stripped nearly everything out of my car. In hindsight, its dumb to do that. I would have maintained as much factory wiring as possible if I could do it again.

[OldCarNewTricks]

I've heard that one of the major things that has made it easier for car manufacturers to jam so many electronics into cars is the use of ground trigger relays, which is what I have intended to do for my Camaro. I am very open to the idea of doing similar for the 242. Just seems a lot safer in cases like the headlight switch, especially for my poor old connector that is melted and destroyed by heat.

[OldCarNewTricks]

Hindsight is difficult, man! I've done the same, with my Camaro. It's a motivation killer, for sure. I think I'll delete the bulb failure circuit, though. I've heard very little good about it. I intend to leave all the other stock wiring in place, I think.

[MasterBlaster]

Originally Posted by patrickstar

The wiring diagram I came up with. My situation is a little different because I was using an ARC 8000 PDM to complete the relay trigger circuit, and the switch is grounded.

Single spliced green to the switch?
Not separate greens to separate switch terminals?














...and I don't see any grounds!

[patrickstar]

Originally Posted by MasterBlaster

Single spliced green to the switch?
Not separate greens to separate switch terminals?


...and I don't see any grounds!

*Diagram not to scale Turns out Microsoft Paint isn't the easiest software to draw wiring diagrams in

[OldCarNewTricks]

Originally Posted by patrickstar

*Diagram not to scale Turns out Microsoft Paint isn't the easiest software to draw wiring diagrams in

No worries, it's easy to figure out. I've used M Paint before too.. it works!