Vehicle Wiring Dilemma

So I ended up with an old diesel VW Rabbit truck. What I didn't know when I bought it was just how awful a prior owner had hacked up the wiring.

I bought it cheap, not-running, and put it back together with a little help from my friends. Now it's up and running. Hooray!

Luckily, it only takes like 3 wires to make this run. 12V to the injection pump to let it flow. 12V to glow plugs prior to firing. 12V starter trigger. Oh... and a fan switch.

So that's literally all it has right now, and all that was done by the PO with toggle switches. Ignition switch is completely bypassed (probably failed).

The problem is, NOTHING else has power. The cluster is gone. The harness that would've been plugged into the cluster is half cut off (why????). The fuse box is mostly empty, wires, cut, etc. So I have no lights. No blinkers. nada.

Ugh.

Because this is a toy beater anyways, I'm tempted to just improve the current toggle switch setup, racecar style, but then I still need wipers/headlights/brake lights/etc. It still has a heater/fan setup, so it'd be nice if that worked.

So do I...

A) Grab a full "CE2" fuse box and harness from a 90's era VW and strip it down to essentials and splice it in? This has been done by others, but still seems like a lot of work. Plus I still need to find a cluster with a pigtail to splice backwards. ...and I don't know if the ignition switch works. Ugh.

B) Keep with the beater cheap simple diesel approach, and just home-brew a simple switch/fuse panel setup racecar style. Outside of the few toggles it already has (starter/glow plug/injection pump), I really only need a few circuits... headlight/taillight/brake light/blinkers, and powering up the HVAC blower likely wouldn't be too hard. Pretty sure it doesn't have any interior lights anyways. Then I still don't have a cluster, and by the time I do all this, maybe I should've just done it more stock-like and used the factory switch gear.

Just thinking this through outloud because I'm at work. ...and I'm not sure how much work I want to do to a beater $1,000 pickup, but I do actually want to drive it.

How much of the original switch parts are there?

If you were going to do A, I'd find a better match than the 90's VW- that will certainly have stuff in it for the engine that you don't have. Unless that's the only way to match the switches you have.

B isn't that hard, if you have a wiring diagram, you can basically copy that, including the fuse box numbers. It seems painful to hand wire a vehicle, but it's not nearly that hard. The actual hardest part is finding the different color wire- that's where I was most challenged in my hand build.

Your truck is roughly as simple as a carbed car. So it's not going to have much.

if you have a 4x8 sheet, you can lay the whole thing out on that.

1. That thing is one of the coolest things I have seen in quite a while. Well done.
2. I'm very sorry about that wiring fiasco. Huge bummer. Are you planning to replace the cluster with another stock type? If so, i'd try to grab another wiring harness.

But keep in mind it may not be that bad. It only takes a few cut wires to make everything not work, so that might be most of the damage pictured there. An afternoon with some wire and a crimper and pin tool and you might be mostly back in business.

That. Truck. Rules.

I've had a 1979 BMW coupe with effed up wiring for about six years now. Time and time again I have spent hours trying to fix an electrical issue by piecing together what's still in the car, and other BMW scraps. I have never been totally stymied, but still . . . .

If I had it to do over again, I'd toss it all and go with a racecar setup. It just hasn't been worth the amount of time I have put into it. But I always think, "well, I'll just take the time to fix this one thing, and then I'll be all set."

I know from experience with one of my other hobbies, building vacuum tube audio from scratch: the only way to troubleshoot an electrical circuit and make it reliable, is to know every connection and component, and be able to test every one of them systematically.

alfadriver wrote: How much of the original switch parts are there?

All of them as far as I can tell. Headlight switch is there with nothing plugged in, blinker stalk is intact, hvac controls all there, etc.

Robbie wrote: 1. That thing is one of the coolest things I have seen in quite a while. Well done.

Thanks! I already had the 16" Porsche 928 7-slots, and the truck came with cheap drop coils (and an axle flip)

Robbie wrote: 2. I'm very sorry about that wiring fiasco. Huge bummer. Are you planning to replace the cluster with another stock type? If so, i'd try to grab another wiring harness. But keep in mind it may not be that bad. It only takes a few cut wires to make everything not work, so that might be most of the damage pictured there. An afternoon with some wire and a crimper and pin tool and you might be mostly back in business.

Ideally I'd like to have the hole in the dash filled, so yeah if I can plug in a cluster that would be nice. The speedo is mechanical off the trans with a cable, so at minimum I'll find one and do that.

Yeah I guess I still need to do more poking around, often on these a rust leak develops at windshield and drips on the fuse panels and eventually everything just quits working. There is evidence of a rust hole that may have done that here. Thus the starting over as the baseline scenario.

Im just jealous, my dad was a vw tech and ive always had a weird lust for one of those trucks!

xflowgolf wrote:

alfadriver wrote: How much of the original switch parts are there?

All of them as far as I can tell. Headlight switch is there with nothing plugged in, blinker stalk is intact, hvac controls all there, etc.

So IF most of the original harness is there, too- can you take apart one of the connectors?

The easiest thing would be to get a new set of pins for the connectors, cut all the wires even, crimp on new pins, and re-insert into the connector.

I've not seen a connector where you can't take the pins out- with some kind of poking device.

It won't be fun with a crimper in a tight spot, but if it's all there, it wont be too bad. You'll have to buy a good crimper too, not just use some easy multi tool. And the number of pins you need should fit well under the number of engineering samples xflowgolf racing can ask for from Molex (for free). Just have to figure out what they are...

Based on my experience, The original problem that led to all the cobbling is likely the fusebox, combined with a poorly sealed windsheild.

After fixing the hacked light wiring in my truck the radio stopped working. So I understand this pain.

Get a manual that has the harness diagrams in it and just wire what you need?

Streetwiseguy wrote: Based on my experience, The original problem that led to all the cobbling is likely the fusebox, combined with a poorly sealed windsheild.

Some years had an issue with a cleverly routed radio antenna wire that diverted rain water from a poor antenna gasket seal into the fuse box as well.

For what little it's worth, I vote for race car style toggle switches and swap meet gauges mounted in an aluminum panel where the instrument cluster used to reside.

Also, we need more pictures.

Depending on how much of your dash still exists or is assembled that ignition switch can be a real pain in the dick even though it's a ~$7 part. I personally would keep the switch bypassed but try to get most of the original equipment running through the factory wiring with the ignition switch being bypassed with some sort of switch or switches based on how much i cared about other people trying to start my car.

Also i hate you because i have a 1984 Dodge Rampage and rare factory VW-engine mounts setup and vw-bellhousing auto trans sitting here waiting for me to find a sufficiently near-free VW diesel to install, and so far i havent found one!

Look at universal hot rod harnesses.

link $69

Vigo wrote: Depending on how much of your dash still exists or is assembled that ignition switch can be a real pain in the dick even though it's a ~$7 part. I personally would keep the switch bypassed but try to get most of the original equipment running through the factory wiring with the ignition switch being bypassed with some sort of switch or switches based on how much i cared about other people trying to start my car.

I think that's where I'm leaning at the moment. Something like this makes that fairly appealling:

wheelsmithy wrote: link $69

Ooooh. thanks for the link!

wheelsmithy wrote: link $69

Whoa. That is a really good deal. I have been having evil thoughts about gutting one of my cars and going race car dash. This looks to be a good starting point.

I'd be careful with those really cheap harnesses, some of them are made with really crappy wire, or at least that's the case with the cheap headlight relay harnesses.

In reply to wheelsmithy:

I also thank you for that link.

BrokenYugo wrote: I'd be careful with those really cheap harnesses, some of them are made with really crappy wire, or at least that's the case with the cheap headlight relay harnesses.

Yep, it seems I could have spoken too quickly, but to run lights, heater and wiper on a diesel, how bad could it be?

^famous last words. My diesel Dodge may be a guinea pig for this particular bad idea someday.

wheelsmithy wrote: link $69

BrokenYugo wrote: I'd be careful with those really cheap harnesses, some of them are made with really crappy wire, or at least that's the case with the cheap headlight relay harnesses.

Well we'll see how it goes. I just ordered this setup, so I'll give a review on it's arrival. I couldn't find much on the Googles for reviews of that company. No reviews on Amazon for this specific harness, but their products with more circuits (14 and 21) had generally positive reviews and written comments, so that gives me some hope. At the price, I figured it's worth a shot.