1980 Rabbit Diesel manual Project

[acidtonic]

I'd be careful to not backfeed the switched accessory bus

Thanks for that advice, I was going to do that and you saved me. I'll make sure to just cap off and electrical tape the original wire to that molex then and only connect my dedicated-and-fused 12v wire directly to the molex.

Also is it a problem if I use 10 gauge wire and a 20-amp fuse? I got one of the non-vw standard inline fuse holders. It came with a 30amp but I swapped it out for a 20. Since the next smaller size in that fuse family is a 15amp I decided against that because it's 1 amp less than the original 16amp fuse and I figure with 35 years of age this motor likely needs a bit of extra help. Will that be an issue?

Thanks again for all the help, this is really coming along

[TylerDurden]

Also is it a problem if I use 10 gauge wire and a 20-amp fuse? I got one of the non-vw standard inline fuse holders. It came with a 30amp but I swapped it out for a 20. Since the next smaller size in that fuse family is a 15amp I decided against that because it's 1 amp less than the original 16amp fuse and I figure with 35 years of age this motor likely needs a bit of extra help. Will that be an issue?

AWG10 is beefy enough, for sure. lol.

I would go for the 15A fuse though, the existing wiring is only rated for 16A... and 20A is 25% overload. I'm not confident the old connectors and motor will tolerate the extra current.

[acidtonic]

Could be a bad measurement but I could have swore I only got 6 volts when I tested through the switch with a wire ran to the + battery connection, is that bad? I was able to turn it and watch the current move between each leg however. Wondering if I should just run a ground cable directly to the other side of the switch after removing the wire that used to be there (backfeed).

Plus since this is a ground switched car, doesn't that mean I want to avoid backfeeding ground and not positive 12v? I basically at this point think it's safest to isolate both sides and just wire ground to the 4-way switch and then 12v to the black/red on the molex then directly to the battery through my 15amp fuse... seems logical enough as long as both sides original wires get capped and taped off first. I'll solder in the two wires unless that's a bad idea or something.

[TylerDurden]

Hrrrmm... I haven't got a Rabbit book handy ATM, but all my other MK1 books within reach show the hot feed getting switched through the resistors before the fan and the fan to ground.

I'd try to get a bona-fide diagram for the AC model before cutting and splicing.

I'd check the meter setup too, there should never be a spark when probing, unless measuring current and even then not if probes are in place before the circuit is energized.

HNY,
TD

[acidtonic]

Hrrrmm... I haven't got a Rabbit book handy ATM, but all my other MK1 books within reach show the hot feed getting switched through the resistors before the fan and the fan to ground.

I'd try to get a bona-fide diagram for the AC model before cutting and splicing.

I'd check the meter setup too, there should never be a spark when probing, unless measuring current and even then not if probes are in place before the circuit is energized.

HNY,
TD

It's odd because I'm seeing ground at the 4-speed switch.... That must be the issue in reverse then.

Here's the thread I was looking at that mentioned 1980 switched differently. http://volkswagenownersclub.com/vw/showthread.php/43201-Need-Wiring-Diagram-for-1980-Rabbit-Fan-Blower-Circuit-or-help-with-question (post #4)

[TylerDurden]

You hit the jackpot with that thread.

Your plan should work.  I'd feed 12V through a relay triggered by the switched-hot as discussed earlier. I'd also replace the ground wire first to see if that alone solves it.

It is possible one of the AC relays is bad... the ones in the engine compartment are more vulnerable to the elements and corrosive vapors if the battery is close. (I had to shunt around one in my 86TD after its AC died.)

[acidtonic]

Well I wired it up completely bypassing the main switch harness and left the molex unplugged. Seems to work flawlessly and I have all four speeds. Even though the car was warmed up I still was getting cold air out of the hand-vents. I think the vacuum actuators may not all be functioning properly or it's by design (not sure).

What I find is that the outside air vent flap (in the rain tray) will only close if I move the temp-slider all the way to max-cold. If I move the lever back to heat it opens up again. I don't know if that's normal but since the flap is open I believe thats where the cold air is coming from. If I put my hand up by the defrost area and turn the fan on I can feel hot air coming out but then if I switch the hand-vent open only cold air comes out.

At least the vacuum system holds pressure and works better than it did when I got it..... I started spraying some rust neutralizer up in the rain tray area and started taking some photos. Tonight I'll spray some rubber sealant around the heater-fan box in the rain tray. I have the earlier version that has no screen over the cold-air door so I'll rig up something to keep debris out of there. I do have a plastic rain tray cover but it's not enough on its own to keep leaves out. I'll fab up something.

I'll post my photos after taking them off the camera tonight. Cheers.

[TylerDurden]

...Even though the car was warmed up I still was getting cold air out of the hand-vents. I think the vacuum actuators may not all be functioning properly or it's by design (not sure)...

What I find is that the outside air vent flap (in the rain tray) will only close if I move the temp-slider all the way to max-cold.

This is normal for Rabbits, as I recall.

Side vents in the dash are always fresh air.
Max-cold is the same as "re-circ" in newer cars.

[acidtonic]

This is normal for Rabbits, as I recall.

Side vents in the dash are always fresh air.
Max-cold is the same as "re-circ" in newer cars.

Wow, I checked my manual before reading your post and was absolutely dumbfounded to find the exact same thing. Who would design it that way? So when it's -5* outside I have to put my hands *where* to warm them up? Yeah I'm being overly dramatic

I think the first thing I'm going to do is figure out how redirect the foot vents solely into the main vents since I need the air out of there well before the foot area. However finding that out made me feel good about my repair and glad I don't have to tear the dash apart.

Tomorrow I'm going to mess with the car some more and apply more rust proofing and sealant, then fab up some screen over the entire rain tray to keep debris out when finished. I looked in the owners book and it's odd that the car was purchased in this county originally yet I bought it from an hour away. I guess I'm bringing it back home

Owners manual was filled out with stickers over the gas towing instructions which tells me it's a factory diesel for sure and not a swap. It was lightly driven apparently, purchase date was September 16th, 1980. It has the entire service booklet filled out with authentic VW dealer stamps all the way up to 1985 where it only had 55,000 miles (84,000 right now). In the last 30 years it only gained less than 30,000 miles which is impressive and received authentic dealer maintenance the first 5 years.

I also have a repair bill for 2 shocks and struts which were done in 1985 and then a stapled copy over it where they warrantied the same two shocks again in 1991 for only the cost of labor. Very interesting and fun going through the paper trail of effects I found in the glovebox.

[acidtonic]

(dupe post, I'll edit with some photos here soon)

[TylerDurden]

One of the first things I did to my first rabbit was to fix the seals on the outer vents, lol.

That was after a drive between NYC & Detroit got so damn cold, I stuffed spare socks from my luggage into those mothers so we didn't freeze.

[acidtonic]

My center two vents aren't blowing any air at all. I'm seeing guides for fixing the side vent open/close lever but what about the centers? Apparently those put out hot air which is enough to warm the hands so I want to get those working.

[acidtonic]

I forgot to mention this got sold awhile ago, but today I bought a new gem! Picked up a 1983 Rabbit 4 door with blue paint and a 1.6 diesel engine. 4 speed manual. Drove it an hour home very solid ride. Very little rust on the bottom and both floors original and completely spotless underneath. Time for more work and I'll start a new thread.

http://imgur.com/a/eS26L