TheSamba.com :: View topic - List Of All Electrical Ground Points In 88 Westy?

Mon Sep 20, 2010 7:04 pm

Hi guys. I am having a no-start problem with my 88 Westy. Cranks but no start. First clue is that voltage across the leads to the fuel pump is low and variable when starter is cranking (fluctuates from 0v to 9v) and even lower when key is "on" (0v to 5v). So I guess I need to check all my grounds.

Can anyone give me, or point me to, a comprehensive list of where all the grounds are? I know about the left side of the engine bay and the transmission nose.

Thank you.

I figure that, even if cleaning one ground solves the problem, I should methodically find and clean all of them. After all, they probably haven't been cleaned in 20+ years.

Mon Sep 20, 2010 7:41 pm

The Bently diagrams have a list, section 97.121 for the 88. The circle symbols appears in the diagrams so you know what circuits ground where. The fuel pump grounds in engine compartment left. Have you contacted Bostig?

Mon Sep 20, 2010 10:30 pm

Assuming you did not make my mistake and forgot to tighten the battery terminals (I set it on to try the starter and it worked fine until a bump in the road bounced the ground side off), you may need to look at the alternator and the starter connections. If this is on your Bostig conversion, call Jim tomorrow and he or Brady will get you pointed in the right direction.

Sat Sep 25, 2010 3:43 pm

Thanks.

I looked at the van today but didn't see any loose connections, specifically at alternator or starter. The starter cranks fine and the ground at the transmission nose is fine. The engine compartment ground (left side, under round coolant tank) looks fine.

I checked voltage at various places where I think I should see 12v (terminal inside distribution box, terminal inside ECU box) and did get 12v or pretty close (11.5-12.0v) - this is relative to the engine compartment ground.

I also tried connecting the fuel pump positive terminal directly to the battery positive terminal, then the fuel pump ran (at least it made "running" noise) but I still got the "crank but no start" result.

I put in a support ticket, I'm sure I'm overlooking something simple.

Sat Sep 25, 2010 3:59 pm

The wiring stud in the wiring distribution box needs to maintain near 12 volts DURING cranking so measure it while trying to start.

Mark

Quote:
I checked voltage at various places where I think I should see 12v (terminal inside distribution box, terminal inside ECU box) and did get 12v or pretty close (11.5-12.0v) - this is relative to the engine compartment ground.

I also tried connecting the fuel pump positive terminal directly to the battery positive terminal, then the fuel pump ran (at least it made "running" noise) but I still got the "crank but no start" result.
.

Sun Sep 26, 2010 12:09 pm

Well, Mark, that was interesting.

I measured the voltage on the positive terminal in the distribution box (relative to the engine ground) when the starter is cranking. It was 4v to 6v. Versus 12v when the key is "on".

What causes that?

I also removed, cleaned, and re-attached the ground at the transmission nose. Now resistance between the engine compartment ground and the engine block is 1 ohm.

Sun Sep 26, 2010 12:53 pm

There you go, that is a problem. The ECU gets it's power from the distribution wiring box stud. The ECU needs something like at least 10 volts to run. The wiring stud gets power from the starter motor main wiring stud, which is always connected directly to the battery by the large + battery cable. You probably need to clean and tighten the starter motor connection. Then verify that there is a red wire from the starter stud to the wiring box stud. Then check that wire for damage or bad connector crimps.

Mark

jyl wrote: Well, Mark, that was interesting.

I measured the voltage on the positive terminal in the distribution box (relative to the engine ground) when the starter is cranking. It was 4v to 6v. Versus 12v when the key is "on".

What causes that?
..............

Sun Sep 26, 2010 5:12 pm

crazyvwvanman wrote: ... distribution wiring box ...

is this the black box with the 2 relays in it?

Sun Sep 26, 2010 5:28 pm

No, it is the other black box forward left side in the compartment, with all the colored wires in it, used in 83+.

The one with 2 relays in it is part of the fuel injection wiring and often gets removed with engine conversions.

Mark

randywebb wrote: crazyvwvanman wrote: ... distribution wiring box ...

is this the black box with the 2 relays in it?

Tue Sep 28, 2010 10:15 pm

Van running again. Nut on starter stud had backed off , under the rubber boot. Battery cable was sort of making contact, other wire was not making much contact. Think, in retrospect, this has been getting worse over a few weeks, because the van has been slow to fire lately. Tightened nut with loctite and all is well. Thank you, all, and especially Mark.

Very timely, I've been riding the Vespa or the bus to work, but winter is coming . . .

Now, to get the 911 working right. That's the next project.