Wiring Accessories

This post is for future reference when wiring accessories. The Vanagon fuse box gives you an easy way to connect accessories. Here is a diagram of the back side of the fuse box.

"G" Pins

In the diagram above you can see that there is a group of 10 spade connectors with a "G" to the right of them. They are numbered 1 through 10 like this:

G1 G2
G3 G4
G5 G6
G7 G8

G9 G10

These connectors allow you to tie into existing circuits in the wiring harness. You can trace down what they connect to by looking at the Bentley wiring diagram. Just scan horizontally along the connections to the fuse panel (lowest horizontal line at the top of the page). Below are some brief descriptions of each circuit for my 87. I've added some of the relevant current track numbers for quick reference.

G1 - "X Bus" Ignition "Run" Only (fused)
G1 (track 164) taps off of S12 (20A). S12 is fed by the X bus. This means it is hot only when the ignition switch is in the "Run" position. There are also several other fused circuits that are fed by the X bus. All circuits on the X bus are connected to the output of the Load Reduction Relay (track88). The circuit that is fed by S12 also includes the heater blower, rear wiper, cruise control, A/C, rear view mirror adjustments, and G3.

G2 - Ignition "Start" and "Run" (fused)
G2 taps off of A25 (track 135). A25 is fused by S18(10A), and comes directly from the ignition switch. It is hot when the switch is in the "Start" and "Run" positions. G2 is also connected to D7, and G5.

G3  - "X Bus" Ignition "Run" Only (fused)
Connected to G1.

G4 - Alternator Warning light (not fused)
G4 is connected to A16 which taps off of the alternator warning light (track 51). Warning light connects to D+ on alternator (track 6).

G5 - Ignition On (fused)
Connected to G2

G6 - No Function
Connects to D1 and A4 (couldn't find any other connections).

G7 - Headlights On (not fused)
G7 is connected to A9 (track 88) which taps off of headlight switch pin 56. G7 is hot only when the switch is in the "Headlights On" position, but not in the "Park" position. It is not fused because the headlight fuses are after the high-beam switch. Also Connects to M1.

G8 - Instrument Lighting (fused)
G8 is connected to A1. A1 taps off of the instrument lighting circuit. In my van an extra fuse (10A) is clipped onto the top of the fuse panel. All of the instrument lights and G8 are fed from this extra fuse. The fuse is fed by pin 58b on the light switch. So, G8 is dimmed just like all of the instruments.

G9 - Lights On (fused)
G9 is connected to E1 (track 97). E1 is fed by S20 (10A) which is fed by pin 58 on the light switch. G9 is hot when the light switch is in either the "Park" OR "Headlights On" positions. The license plate light is the only thing fused by S20.

G10 - Windshield Washer Pump (fused)
G10 taps off of A19 which is fed by the windshield wiper switch pin "L" (track 158). When the switch is in the "Wash" position, G10 is hot. Pin "L" is fed by Pin 53a which is fed by S11 (15A).

"P" Pins

There is another group of pins on the diagram above with a "P" next to them. These are all the same, and are connected directly to the battery. They are not protected by a fuse.

Note: I got this information from looking at the Bentley wiring diagram for the Water-cooled Digifant 1987 Vanagon. If you have a different model, check the Bentley for possible differences.

Gas Tank Replacement (first attempt)

If you don't have a Vanagon, you may not know about some of the maintenance issues on the gas tank. They have more connections than most gas tanks, and the rubber grommets that seal these connections get old and can leak with age.

After getting the Subaru engine in, and running, I found that the gas tank leaked when it was filled up. It ended up only being a disconnected breather line, but I decided to completely replace the tank and all of the breather lines and grommets.

Unfortunately when I tried to fill it up after installing the new tank, it still leaked just as much. See the post on my second attempt for the solution to that problem. This post may still have some pictures of interest since there are some things listed here that I won't cover on the second attempt.

I decided to remove the front wheels to give me better access to the vent lines and the top of the tank. I don't really think this was necessary. The best way to get visual access to the top of the tank was to remove the spare tire and holder. Then I could see all of the front vent lines.

Set the brake.

Got the van on jack stands.

Disconnected ground.

I pinched the outlet hose, and removed it at the pump. Then I drained the gas into several cans.

Here is the main problem that was causing the leak initially (viewed from front spare tire area with tank still in place). I probably could have fixed my problem by replacing the the cross over tube, but I really wanted everything on the tank to be new and good for years to come.

This was my first approach to lowering the tank. I later found that my large jack right in the center of the tank worked the best. It also worked good to duct tape a rag to the lift pad on the jack to avoid scratching the newly painted tank.

I cut the hoses to the expansion tanks.

Removing the trim ring made taking out the filler neck easier.

The filler neck came out easily by just pushing it into the tank slightly and turning it to the right.

The old tank.

I used some scotch bright and sand paper to prep the old tank for paint.

The paint fumes got pretty strong, so I got an inexpensive respirator.

I used these for the lines that go to the expansion tanks. They were a little too small though, and tough to get on.

Here is a comparison of the old cross over tube assembly, and the type sold by van-cafe.com I mistakenly thought that the cross over hose was a little too long as it came from VC, to I shortened it. I should have left it the length they had it.

Another comparison picture.

This shows me twisting the fuel sender in with a screw drive. It was the o-ring on the sender that ended up leaking on the new tank installation.

One of the expansion tank hoses.

I don't think it's required, but I put some of this stuff on the grommets before installing them.

Quite a bit of sealant squeezed out when I installed the grommets.

It looks better after the excess sealant is wiped away.

This is the filler neck grommet. I used sealant on it too.

Since the Van-Cafe cross over tube is a lot thicker than the stock plastic tube, I decided to use a different type of clamp to hold it up in the center. The stock one would have been too small. I used a standard padded cable clamp. This clamp was also a little too tight though. I removed the rubber padding, and replaced it with a large heat shrink tube. This allowed the cross over tube to move freely. This made installation much easier.

This is the clamp in place. You can see the emergency brake cable nearby. I think this is the main reason for the clamp. It keeps the cable from contacting the hose.

Lifting the tank back into place. I later found that a rag on the jack lift pad worked the best.

I replaced the bolts on the tank supports, but the first set I tried were a little too long and contacted the tank slightly.

I think the correct length is about 20mm.

Initially I just left these hoses long and then trimmed them to length after the tank was installed.

Drivers side. Connected expansion tank lines, filler neck, and filler neck breather hose.

Fuel outlet reconnected.

Return line reconnected.

Tank back in.

Gas Tank Replacement (2nd try)

After replacing the gas tank and all the related vent lines and grommets, I felt confident that everything was perfectly sealed. When I went to fill the tank though it leaked out on the ground as much as ever. It turned out that the o-ring on the fuel level sender was not sealing properly.

It was easy to see where the leak was because of the paint that the gas washed off.

The second attempt was successful though. Here are the steps I followed (see the first attempt here):

• Paint tank with whatever type of paint you prefer.
• Connect breather hoses to rear breather pipes with small hose clamps (leave long for now)
• Connect filler neck breather hose to tank fitting and leave long for now.
• Install filler neck breather grommet into tank (use fuel resistant sealant if you prefer)
• Insert breather hose fitting into grommet.
• Install filler neck grommet into tank (use fuel resistant sealant if you prefer)
• Install the 2 crossover grommets (use fuel resistant sealant if you prefer)
• Install fuel sender unit (easier said than done!)
• Assemble crossover tube with fittings and breather tubes (use hose clamps and leave breather tubes long for now)
• put crossover tube into van held in place by hose holder under van (best if hose can move in the holder).
• Jack vehicle up in front as high as possible.
• Remove front wheels if desired (I found that this didn't really help that much).
• Remove spare tire and tire carrier (I feel this is the key to good access to see what is going on)
• Place tank on Jack (I duct taped an old towel to the jack to avoid scratching the paint)
• Lift tank into place (tip front up first)
• Plug in sender unit plug (don't forget this or you will be lowering the tank back down)
• As you lift the tank, feed breather tubes up over the sides of the frame.
• When the tank is in place, install tank supports (one support will hold the tank if you need to remove the jack).
• Reach through wheel wells and push crossover fittings into their grommets (use some lubrication).
• Cut the 4 breather lines to length and attach them to the vapor tanks
• Lubricate the end of the filler neck and insert it into the filler neck grommet (twist the cap toward the wheel and then rotate to the final position).
• Connect filler neck to trim ring with screws (the filler neck may be easier to install with trim ring removed).
• Cut filler neck breather hose to length and attach with a hose clamp.
• Connect fuel outlet and return lines with hose clamps.

I thought I had taken more pictures of the fuel sender, but I can't find them now. Basically what happened is that the tabs around the edge of the opening in the tank cut into the plastic on the sending unit. There are "ramps" around the outside of the sender that are supposed to pull the unit down against the o-ring.

I think there are several things that contributed to this. One thing is that the metal tabs were too sharp on the bottom side. I sanded the underside of them on the 2nd try. I also smoothed out the leading edge with a file.

Another thing that could have been part of the problem is that the pressure on the tabs was not equal all around. When you tried to twist the sender to engage the tabs, it was tight on one side, but not as tight on the other. I made a very slight adjustment to the tabs with a small pair of vise-grips. This resulted in the tabs being very snug and exerting even pressure all the way around.

Here is the sender after being installed the right way. I was surprised that after my adjustments, the sender went in with less effort than the first time (when I was actually forcing the metal tabs to cut through plastic). I didn't have to use a tool to turn it. Although it was very difficult, I was able to turn it with my hand (just barely though).

I plugged all of the openings to do a pressure test. This is a rubber stopper from the hardware store plugging one of the cross over tube holes.

After installing all of the new components I tested to make sure that the tank would hold pressure. I plugged all of the openings, and attached a baloon to one of the expansion tank breather lines with a zip tie. Then I gently blew a small amount of compressed air into the tank. The balloon remained completely inflated for at least 15 min.

I attached an old towel to the top of the jack. This worked well to lift the tank without scratching the new paint and undercoating. I used duct tape to hold it in place.