Itinerant Air-Cooled

Does anyone know where does the Vanagon fuel pump ground? My pump is starting to cut in and out. It's not running hot, but it feels like its on its last breath.

Thank you,

The book says its at fuse relay panel. Does that mean that the ground is fused on the fuse panel?

Just behind and next to the fuse panel are two circular multi-prong grounding connectors screwed into the body. My guess would be that is the terminal in question. You can see these connectors if you loosen and drop the fuse panel, or if you remove the instrument cluster and look down.

Dropping the fuse panel is probably the easiest option, but disconnect your battery positive terminal first. There are some live terminals on that fuse block with nice big fat wires attached to them, and they will create some pretty exciting sparks if they happen to brush against any grounded part of the car.

Thank you. My fuel pump has been cutting in and out a bit, like its hanging up or seizing. It is an old pump... probably original. I will be replacing it, just in case, and will also be running a new ground right to the body under the fuel pump.

This is for non-stock installation.

luftvagon wrote:Thank you. My fuel pump has been cutting in and out a bit, like its hanging up or seizing. It is an old pump... probably original. I will be replacing it, just in case, and will also be running a new ground right to the body under the fuel pump.

When my pump died, it just stopped. No warning, no cutting in and out. One second I was merrily cruising along, the next I was dead by the side of the road.

I'll suggest you check out everything external to the pump before blindly replacing it. If you can get a voltmeter across the pump terminals and observe the voltage as it does it's cutting in and out, that might help. Use an analog VOM if you have one: a DVM may not be fast enough to catch momentary voltage drop-outs.

It's probably a worthwhile exercise to drop the fuse panel and clean up your grounds behind there anyways. A lot of grounds get terminated there, so if you suspect a problem with one ground, then there are likely to be problems with other ones.

And if you're going to go to the trouble of running a new ground for the pump, why not just run it directly to the battery negative post? It's in the same vicinity as the pump.

SlowLane wrote:

luftvagon wrote:Thank you. My fuel pump has been cutting in and out a bit, like its hanging up or seizing. It is an old pump... probably original. I will be replacing it, just in case, and will also be running a new ground right to the body under the fuel pump.

When my pump died, it just stopped. No warning, no cutting in and out. One second I was merrily cruising along, the next I was dead by the side of the road.

I'll suggest you check out everything external to the pump before blindly replacing it. If you can get a voltmeter across the pump terminals and observe the voltage as it does it's cutting in and out, that might help. Use an analog VOM if you have one: a DVM may not be fast enough to catch momentary voltage drop-outs.

It's probably a worthwhile exercise to drop the fuse panel and clean up your grounds behind there anyways. A lot of grounds get terminated there, so if you suspect a problem with one ground, then there are likely to be problems with other ones.

And if you're going to go to the trouble of running a new ground for the pump, why not just run it directly to the battery negative post? It's in the same vicinity as the pump.

Good idea. I checked everything on the back-end side (power-sofware-relay-power-fuse-fuel-pump), and the only thing that I could not track was the ground.

Its the AMPS you want to check. If it is above spec, then it is at the end of its life. I think 5-6 Amps is about right...higher than that is a problem. (assuming no blockage in line or filter)

SlowLane wrote: new ground for the pump, why not just run it directly to the battery negative post?

I recommend that you keep the battery negative terminal/post free and clear. There is no reason the metal of the car cannot handle all electron delivery needs for a fuel pump. The negative terminal is one of those things that if you need to yank it off NOW, let it be unencumbered.
Colin

Amskeptic wrote:

SlowLane wrote: new ground for the pump, why not just run it directly to the battery negative post?

I recommend that you keep the battery negative terminal/post free and clear. There is no reason the metal of the car cannot handle all electron delivery needs for a fuel pump.

Yeah, I was just thinking out loud and stirring up s**t.
Frankly, I figure that if VW went to the trouble of running that extra copper to the grounding block behind the fuse panel instead of just running a short jumper to the frame, they must've had a good reason (google "star-ground" and "ground-loop", ferinstance). And to reiterate, if there is a suspected ground problem at the block, I maintain it ought to be fixed there, rather than bypassing it, because who knows what other gremlins might be lurking elsewhere due to that flaky ground connection.

SlowLane wrote:

Amskeptic wrote:

SlowLane wrote: new ground for the pump, why not just run it directly to the battery negative post?

I recommend that you keep the battery negative terminal/post free and clear. There is no reason the metal of the car cannot handle all electron delivery needs for a fuel pump.

Yeah, I was just thinking out loud and stirring up s**t.
Frankly, I figure that if VW went to the trouble of running that extra copper to the grounding block behind the fuse panel instead of just running a short jumper to the frame, they must've had a good reason (google "star-ground" and "ground-loop", ferinstance). And to reiterate, if there is a suspected ground problem at the block, I maintain it ought to be fixed there, rather than bypassing it, because who knows what other gremlins might be lurking elsewhere due to that flaky ground connection.

I *believe* that VW ran the fuel pump grounds to where you could diagnose the (+) and (-) in proximity to each other. That is why they went through all that ground wire junk to the double relay on the earlier buses, I *believe*.
ColinItsAboutFaithBasedDiagnostics

Update : Just when you think you nailed it...

I run a ground jumper. In the mean time, the power spade terminal breaks off.. No problem. That could have been my problem all along. Crimp another spade.
Problem feels solved.. but then BAM. Another event... Fuel pump is bucking.

Problem is back -- so it wasn't the ground, it wasn't the spade terminal at the fuel pump.

Go back and move the fuel pump power source so it is not computer/software switched.... BAM. Problem reproduced.

We are left with two possible culprits red/blue power cable to the fuel pump, or the fuel pump itself.

Has anyone experience such a fuel pump failure?

luftvagon wrote:Update : Just when you think you nailed it...

I run a ground jumper. In the mean time, the power spade terminal breaks off.. No problem. That could have been my problem all along. Crimp another spade.
Problem feels solved.. but then BAM. Another event... Fuel pump is bucking.

Problem is back -- so it wasn't the ground, it wasn't the spade terminal at the fuel pump.

Go back and move the fuel pump power source so it is not computer/software switched.... BAM. Problem reproduced.

We are left with two possible culprits red/blue power cable to the fuel pump, or the fuel pump itself.

Has anyone experience such a fuel pump failure?

Classic internal electrical impending death that strikes fuel pump motors, wiper motors, starter motors, defroster motors. Many times they get intermittent as they warm up (electrically). You are the person in the position to bypass the factory red/blue wire to see if the pump now runs consistently.

Got a spare pump?
Colin

How many Amps ?????

dingo, I believe it's 4.5amps. I'll get an update with pictures. Everything fit perfectly. I'm even running a nice pre-filter which is common from any parts store without having to special order. Update coming tonight with pictures!