1980 Rabbit Electrical Woes

[josh.d]

Hello again and before I start I want to thank you all once more for your input on my 'mystery bolt' that ended up being an intake manifold bolt. I'm getting further in to the car and have solved (some with a mechanics help) a number of issues. I have replaced the timing belt, had the valves adjusted and the IP re-sealed. Now that I am driving the car I am noticing a strange electrical issue that happens only when the car is running. I have replaced the grounds in the engine bay with new runs of heavy gauge cable from a scrapped set of jumper cables. The problem I am having is that when the car is running sometimes the glow plug light will flicker or stay on. The glow plug light also flashes with the blinkers when they are engaged and when the brake pedal is depressed. I also installed a tape deck and it shuts off when any of the other things are engaged, like the blinker or the brake pedal. When the key is on the 'glow' position some times the load reduction relay or 'x relay' will buzz or make strange sounds and the glow plugs and relay wont kick on. The other thing that concerns me is that one of the previous owners have a wire jumped off of the bottom pin of the load reduction relay. This makes me wonder what the jumper is going to, but haven't gotten into it that far yet. My question is should I just replace the load reduction relay? I would have just done that in the first place but the only place I can find one locally wants $16 for the part. I am going to pull the fuse/relay panel and double check the grounds behind it tomorrow. Any advice or comments are appreciated.

Thanks,
Josh D.


EDIT: The glowplug light flicker and blinking was going on before I installed the tape deck, and is disconnected while I'm chasing grimlins.

[bscutt]

it could be the fuse box contacts where the relays plug in. pull both the x relay and the glow plug relay and check for corrosion on the leads and in the fuse box contacts. Reseating the relays a few times could also help. Mine on my 80 Rabbit was so bad I had to replace the fuze box - the contacts were corroded badly and the plastic was melted around them

[josh.d]

it could be the fuse box contacts where the relays plug in. pull both the x relay and the glow plug relay and check for corrosion on the leads and in the fuse box contacts. Reseating the relays a few times could also help. Mine on my 80 Rabbit was so bad I had to replace the fuze box - the contacts were corroded badly and the plastic was melted around them

Thanks for the reply. I have re-seated the relays and I am going to get in there with some electrical contact cleaner today after work. All of the relays and connection points look good, no corrosion etc. I replaced the ground leads under the hood yesterday after work and was working in the dark by the time I got to checking the relay/fuse panel. I'd like to avoid buying a $16 relay that can be had online for a lot less money. I just don't like waiting for auto parts in the mail, but maybe that's just me requiring instant gratification

[bscutt]

Yeah I understand the on line ordering thing but I have a couple of cars so I usually order on line since the dealer is really pricey and I just don't have much time to get to real auto parts stores these days.

It does sound like a circuit is partially open like a bad ground or high resistance connection somewhere. You may have to just mess with it until you find a problem. If you get the schematic and a cheapy multimeter (Harbor Freight ones are 5 or 6 bucks on sale and are perfect for troubleshooting) you may be able to track it down.

[Fatmobile]

Great to hear you got those things done.
That's a great place to start.

ohhh the '80 fusebox
I spent much of last winter swapping a later wiring harness into an early Rabbit.
Pins on the back of the box don't fit tightly into the plugs anymore.
See if Blue(plug) 19 is melted, that's the heater fan. You'll need to relay that on high. Fuse11?? melted?

1-4 fuses are for headlights, ha. If one goes don't change the headlight,.. spin the fuse first, to improve contact.
Get everything you can away from that fuse box, headlight relays, rad fan relay powered right from the battery.

But for now, this sounds like a ground issue, lots of them.
You changed the battery cables, did you keep the frame ground?
Only times I've had the glow plug relay buzz was once when the wire on the battery, the one dedicated to the glow plug circuit, had a loose lug.

Or more common; the ground connection behind the fuse box is loose.
This is on the '81 and newer Rabbits but might be in the same place on earlier ones.

More off topic drivel:
I suggest a negative battery cable that goes all the way to the top starter mounting point.
That trany point is weak.
Could you hit return occasionally? Or it starts to look like a block of words to these old eyes.

[josh.d]

Thanks for the replies.
Today I drove the car all day and it only acted up one time. This was before I used some contact cleaner on the relay panel and relays.
Hopefully it doesn't start up again, if it does I'm going to take the panel out and see whats really going on. I've already replaced all of the grounds in the engine bay so hopefully along with the contacts being cleaned it will behave.

Thanks again.
Josh D.

[supersisu]

Oh the fusebox! I've pinched the female plug ends (inside the plastic connector) with a very skinny jewelers flathead screwdriver to make the plug fit on the post a little tighter. The female end is rolled metal so you can collapse it a little. Then I stuck short lengths of copper wire strands around the outside of the female wire end so it wouldn't bend back. Seems to work so far. The one that gave me the most trouble was the fuel pump solenoid, C15.

[damac]

A jumper from the fusebox sounds like trouble, most of the cars I come across are hacked up when somebody tries to get an accessory to work or to install a radio. If it was me I suggest you pull the dash and trace every darn circuit and make sure everything works. These cars rattle like hell, one loose end bouncing onto car metal can cause a fire!

Your cluster can have frayed leads bouncing around.

Also more than one of the cars I have brought home with tempermental issues ended up being simple things like grounds and also relays that would freak out when powered. Working kind of but doing other wierd things.

Like my last example the flasher relay. Turn to left worked, to the right sometimes. Always flashing fast. Faint green lit up in dash when not flashing. Another relay from the shelf and bam all these problems went away.

You have all sorts of wierd issues going on. My 79 rabbit cluster worked fine for almost a year of daily driving. All hell broke loose I could not believe it, but the battery light wasn't coming on. Didn't pick up on it until I almost ran out of juice. Some other goofy things were happening and I pulled the cluster out and to my horror tons of leads were now exposed from the film in 2 leads going to all those idiot lights. I had this cluster out initially and saw no problems, things worked so I left them alone, installed my radio and drove all the time until this happened. Dash was never even out again so no clue why it decided to let loose. It actually started smoking and starting a fire without blowing a fuse!

[Caerbannog]

Just thought I'd mention that because of the leaky windshields, not only do the fuseboxes get wet and corrode, but the relays themsleves fill up with water. There is really no path for the relays to "drain", though I thought of drilling holes in the covers.

So, you might consider (after noting the orientation of the cover to the guts) gently prying the covers off the relay with a small screwdriver/awl. You might be shocked to find a dripping corroded mess inside. Or hopefully not .

[josh.d]

I got around to removing the knee bar to get a better look at the fuse panel. It has been rainy here lately and there is definitely a leak.
I ran some water on the windshield and the seal is holding the water out and looks to be in really good shape.
Also, I ran some water in the rain tray and watched for leaks in side. I saw some drips coming from the bottom of the rain tray thru the seam up above the fuse box.
Cleaned up the rain tray and the seam inside with hot water and soap. I plan on sealing it up with silicone before any more electrical work is done.
I also noticed when a large amount of water was dumped in the rain tray that the heater was dripping water on the carpet.
What is the best way to seal around the blower motor in the rain tray? I suspect where that is where the water is getting in to the heater.

Thanks for your suggestions and replies.

[Fatmobile]

I think they used a foam seal between the heater box and the body. You must have a non-AC car.
Make sure the rain tray drains are clear, I pull the rubber things out and leave them out. I think they are to keep mice out of the rain tray.
The antenna cable is another source of water. If the body seal is bad water will run right down the cable and drip on the fuse box

[josh.d]

Well I got everything sealed up with silicone and it seems to be holding the water out. I've soaked the car a few times and no more drips above the fuse panel.

I bought an old fuse panel that appears to be in really good shape, no corrosion what so ever on it. So I am going to put the new panel in and see if my issues go away.

One more question for you guys, where are the grounds for the panel grounded to? I looked thru my Bentley manual and it says there should be a ground on the steering column support but I saw nothing there before I pulled the old fuse panel and there is nothing there now. Will the glow plug relay have a direct ground connection to the steering column? Having the fuse panel un-mounted and everything exposed I am not seeing any direct ground connections anywhere.

Thanks again for all the help and replies, this forum is really a great resource for us VW diesel owners.

Cheers,
Josh D.

[josh.d]

I think they used a foam seal between the heater box and the body. You must have a non-AC car.
Make sure the rain tray drains are clear, I pull the rubber things out and leave them out. I think they are to keep mice out of the rain tray.

Fat, the car has A/C, but it looks like it was a dealer installed option, not factory. I have cleaned the drain plugs really well as they were full of muck when this adventure in rabbit electronics started.

The antenna cable is another source of water. If the body seal is bad water will run right down the cable and drip on the fuse box

Initially I thought this must be where the water was getting in because there is a lot of corrosion around the antenna base on the out side of the car. I have checked and double checked the grommet and everything seems to be intact and holding out water.


Thanks for the reply.

Josh D.

[82vdub]

While this doesn't help find the issue, I've been frustrated with Ole 82 and water. It can pour like there's no tomorrow out, and the passenger floor will be dry as a bone. Then, we can have a slight mist, almost like a heavy dew, and there's water on the passenger floor. No coorelation as to where or how the water gets into the cab.

[josh.d]

Just an update:

I replaced the old fuse panel with one I found on eBay. When I got the old one out you could tell it had seen a lot of water, so much that some of the thick red wires that hooked to the spade terminals on the top of the panel were rusted on pretty tight.

I have been driving it and haven't had any issues with the glow plug light blinking with the blinkers and haven't had the glow plug relay act up or make any strange noises. I'm hoping that none of these issues arise again in the future.

Thanks again for all of the input and suggestions, this forum is a great place for a newbie like me to come and learn the ways of the mysterious Rabbit.

Cheers,

Josh D.


EDIT: I might add that I thoroughly cleaned the glow plug relay terminal connections and that I acquired a new glow plug relay. The car came with several different brand relays, all of unknown condition. I figured I better start out with one I know the condition of.