Fixmyvw.com

Author Topic: Mk1 Electrical Upgrades  (Read 4126 times)

August 29, 2015, 09:33:23 pm

Rising

  • Veteran

  • Offline
  • ***

  • 385
    • View Profile
Mk1 Electrical Upgrades
« on: August 29, 2015, 09:33:23 pm »
Hey guys, I've been having a ton of issues electrically with the old bunny. So Ive decided to rip a lot of things out and start fresh. Mainly I want to upgrade the grounds and power wires at the alternator, starter and glow plugs, and the battery of course.

I found this list of grounds for the mk1:
http://forums.vwvortex.com/showthread.php?5284503-Ground-effects-and-the-repair-of-your-car

I think a lot of those are gasser specific. So this was my thoughts(I'll update this thread with pictures and a diy if people are interested once I'm done):

New brass marine wing nut battery terminals
New 4 gauge wire from negative terminal to frame horn (gold terminals)
New 4 Gauge wire from negative terminal to starter bolt
New 4 gauge power wire from alternator output to positive cable( In addition to the stock one)
New 4 gauge wire to the fuse box

New 8 gauge wire from starter bolt to valve cover bolt, daisy chained to strut tower and maybe a few other ground points.

8 or 4 gauge wires to additional fuse block and ground distribution points.

Follow the pimp your glow plugs day

Can anyone think of any other important grounds or wires that need replaced to eliminate flaky behavior? Or other upgrades to the electrical system? I've already got a 90amp alternator, a AGM oversized battery and headlight relays. I heard something about a maybe mk4 automatic starters?


'84 Rabbit Diesel- 1.6D Stock

Reply #1August 30, 2015, 01:25:01 am

ORCoaster

  • Veteran

  • Offline
  • ***

  • 3680
  • Personal Text
    Restoring a Caddy and cleaning the Rabbit for sale
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #1 on: August 30, 2015, 01:25:01 am »
Can you explain to me why you want to run a new wire from the Alternator to the battery and still keep the old one?  Twice the wire means more resistance so what is making you keep the original? 

Puzzled of course. 
Now Own 1981 Caddy as the NEW DISTRACTION to all that is around me.  Project Away!

Reply #2August 30, 2015, 03:11:36 am

vanbcguy

  • Administrator
  • Veteran

  • Offline
  • *****

  • 2835
  • Personal Text
    Vancouver, BC
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #2 on: August 30, 2015, 03:11:36 am »
Two wires in parallel would actually be half the resistance (assuming equal resistance in each wire). Lots of spots that VW does exactly that - for instance the glow plug power feed going through the big round connector on the Mk3 platform splits to two parallel wires, goes through the connector then joins back up at the bus bar. It's a common thing to do in electrical engineering in general.

The gold connectors are totally unnecessary, save your money there. Brand new properly crimped copper connectors will have basically zero resistance. Gold has the advantage when connectors are being unplugged and plugged in again since it doesn't build surface corrosion - stuff like computer connectors that may be unplugged and plugged in again over their lifetime benefit. Copper with a solid mechanical connection that stays put like a ground connection will last decades happily. Add some dielectric grease or Vaseline or whatever on the connection after putting everything together and you're golden.

Sent from my XT1097 using Tapatalk

Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #3August 30, 2015, 06:30:36 pm

ORCoaster

  • Veteran

  • Offline
  • ***

  • 3680
  • Personal Text
    Restoring a Caddy and cleaning the Rabbit for sale
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #3 on: August 30, 2015, 06:30:36 pm »
Thanks vanbcguy,  I was reading your reply and I thought yeah, that's right.  Then scrolled down to see the question.  Surprise!  It was mine.  Holy Mackel, what part of my electronics course and practice did I forget that night.  I know I put in a long day, pretty physical but generally my brain does fart like that often. Thanks for reminding us of the basics. 

If I look under my hood I see that the glowplug hots to at least the 4 individual fuse box is honking huge from battery through relay and then hefty after the fuses.  16 gauge maybe 14. 

Now Own 1981 Caddy as the NEW DISTRACTION to all that is around me.  Project Away!

Reply #4September 01, 2015, 10:45:23 am

Rising

  • Veteran

  • Offline
  • ***

  • 385
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #4 on: September 01, 2015, 10:45:23 am »
Good info on the copper connectors! So metal to metal and then dielectric just to cover the exposed portions? What about solder, I know soldered connections are supposed to be a lot better than crimped. Should I crimp and solder/heatshrink?

How does the wiring for the starter run? Is it running all the way through the key inside? Would it benefit from being relayed?

Also what about windshield wipers? Mine are terribly underpowered. Anybody relaying those?

Sent from my Nexus 5 using Tapatalk

'84 Rabbit Diesel- 1.6D Stock

Reply #5September 01, 2015, 02:50:27 pm

vanbcguy

  • Administrator
  • Veteran

  • Offline
  • *****

  • 2835
  • Personal Text
    Vancouver, BC
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #5 on: September 01, 2015, 02:50:27 pm »
Crimps are actually preferred to solder joints. A good mechanical crimp will be less likely to cause problems over time than a solder joint. VW actually expressly prohibits soldering on wiring harness repairs. Heat shrink is up to you - if you use dielectric grease after crimping and then put heat shrink over top you should have a pretty corrosion proof connection. Heat shrink without something to repel water can backfire and trap in moisture.

The starter has its own relay built in really (the starter solenoid). There's the main power wire from the battery to the starter which is a big thick one, then there's a smaller wire which is connected to the ignition switch. The small wire engages the solenoid which in turn handles the couple hundred amps of current going to the actual starter motor. Nothing really needs to be done there. Glow plugs however are a different story, it's worth using a solenoid under the hood for that. The glow plugs draw a ton of power and it's all going through the bulkhead twice.

If your wipers are slow try dealing with mechanical problems first. Your wiper bushings are probably toast. Putting more current through a motor that's fighting a sticky bushing / linkage isn't going to do anything positive for it. Deal with whatever mechanical issues you might have in that system before playing with the electrical side, it'll make the wiper motor last a lot longer plus it'll reduce its electrical needs.
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #6September 02, 2015, 04:12:04 am

billybobf

  • Veteran

  • Offline
  • ***

  • 318
  • Personal Text
    89 golf 1.8 digi, 1.6 na in pieces in the shop
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #6 on: September 02, 2015, 04:12:04 am »
I used to solder everything.... Was a total solder nut! Then I found out what "open barrel" and "molex crimper" meant google them if you don't know. Prettiest, easiest and most reliable method of doing any wiring!

Reply #7September 04, 2015, 11:34:22 am

RustyCaddy

  • Veteran

  • Offline
  • ***

  • 336
    • View Profile
Re: Mk1 Electrical Upgrades
« Reply #7 on: September 04, 2015, 11:34:22 am »
i was having problems with getting a good ground on the starter and alternator so grounded the bodies of both directly to the battery. This seems like overkill but solved the problems that cleaning the stock grounding wire/contact to engine points didn't help.

Putting a relay in between the fuse box and heater fan motor prevents overloading the fuse box pin in the old style fuse box models (don't know if that is a problem in the later models though).

You can also hook up a relay to the running lights/headlights so the running lights turn off when the ignition is off.  And you can relay the headlights to make them pretty darn bright (people mistake the low beam for high beam sometimes, the high beam is lighthouse bright).

Reply #8February 06, 2019, 01:39:31 am

Broosse

  • Newbie

  • Offline
  • *

  • 9
    • View Profile
Mk1 Electrical Upgrades
« Reply #8 on: February 06, 2019, 01:39:31 am »
its always BOTH a learning process and a P.I.T.A. at times to wire almost any custom built car electrical wiring but if you take notes and label things it will be fairly simple to trouble shoot and maintain

 

S-PAutomotive.com