dead van diagnostic tools, wiring bypass

[tjet]

I just bought a nice Fluke recently to keep onboard.

https://www.fluke.com/en-in/product/electrical-testing/clamp-meters/fluke-362

Ive been looking for a good clamp meter to help troubleshoot draw issues.


Link

[reevesme]

Your device helped me to fix my vanagon today. Thank you, thank you, thank you!!!!

83.5 with a 2.1L engine (replacement) and digijet ignition system. Was having a hot start issue that could have cancelled our trip to Moab.

Coil wasn't get enough current. DIsconnected the fuel pump jumpers first, then the coil feed. Then it would not start again. Reconnected the coil feed; boom fired like a champ.

Thank you, thank you, thank you!!!!

[DanHoug]

[Busfixer]

Dan I was going to wrap the diodes with electric tape but thought the reason they were bare in previous photos was that they get hot. How about a popsicle stick and electrical tape?
Busfixer

[DanHoug]

those diodes can break pretty easily so cut a section of chopstick longer than the leads and wrap electrical tape around the whole mess to bind them to the chopstick support.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[do.dah]

If you have it,, you won't need it!!
The inverse; If you don't have it, you're gonna need it, REALLY REALLY BAD!!

[Busfixer]

Follow-up: I finally received the correct diodes from digi-jet and built the diagnostic wiring harness. I added an optional short lead in case I wanted to power the harness from the alternator stud instead of the positive battery post.

I originally built the harness to diagnose a hard shutdown problem at highway speeds. While I was waiting on DigiJet diodes, I replaced the original ignition switch, changed coil power tap on fuse panel from D15 to D23, and cleaned several relay, coil and distributor connections on 2 yr old parts. The problem disappeared.

But I now feel a lot better having the diagnostic harness in my 88 Bus wherever I go.

Another issue will pop up at some point in the future and the harness is ready!

Thanks, Busfixer

[Backtotheeightiesagain]

There is an emergency bolt on box that fires random sparks into the distributor.
Not seen another one and there is nothing on the Internet about it. Just connect to 12v and King lead. In cap.
Useful diagnostic tool bypass the distributor.
Unfortunately no one makes it now

[DanHoug]

DigiKey is 80 miles from my house... a company of over 5,000 employees in a town of 8,800!! 3 million sq ft. i've been ordering from them for 40 years and have never had a wrong order but mistakes happen.

frustratingly, before Amazon and DeJoy ruined the USPS, i could order parts in the afternoon and have them in my mailbox by 10am next day for $2.99 USPS 1st Class shipping. now it takes a week to get here and has pretty much circumnavigated the state of Minnesota before arrival.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Busfixer]

Thanks Dan, jlr and TJet - I believe Dan is right and these electrical components are capacitors. Dan, when I put them in series as described previously, they would show 6V, 3V, 1V then 0V, allin about 1-1/2 seconds. 0V steady after that. So your recognition of them being a capacitor combined with the quick voltage falloff to0V sounds like you are correct. I will call DigiKey tomorrow. JLR, attached below is a pic of my fine Harbor Freight multimeter in the Diode test position and it reads “1”. Apparently this means no flow. Confirms capacitor idea. Thanks for teaching me that function. TJet, if I don’t get satisfaction from DigiKey, then I may go your route. Thanks for the links.
Thanks again to all - I love the Samba! Busfixer

[tjet]

I made the tool with a Posi-Lock fuse holder, and a diode that fits in like a fuse...

https://www.amazon.com/Littelfuse-02400104P-Diode-...&psc=1

https://www.common-motor.com/posi-lock-blade-fuse-...lkQAvD_BwE

Posi lock brand connector info

https://youtu.be/Yiimgl-Rdmw?si=zVx31hbxa2M2ECPF

[jlrftype7]

[DanHoug]

Digikey RARELY makes a mistake but those are NOT diodes!!! those are capacitors. here's what that part number should look like:

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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Busfixer]

Help! I almost have the wiring bypass built but ran into a snag. When testing the diodes pictured below (50V, 10A), I cannot get voltage to flow through either diode regardless of orientation. 12.8V flows through my test leads hooked in series to my volt/ohm meter, but it quickly drops to 0V when I insert either diode in series. Am I doing something wrong or are these diodes bad? I must admit that I am a rank amateur in the electrical category.
Puzzled, Busfixer

[xflyer]

wherbusche, Best to know what year the Vanagons are as there are different relay wiring(s) and relays on some of them.
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1989 Campmobile, 1984 7 passenger beater Vanagon
Both with cool A/C

[wehrbüchse]

They seem to be correctly oriented unless I'm missing something. Which I suppose would actually be bad news in the grander scheme of things

EDIT well I tested the diodes and they are indeed working as as a one-way voltage path, in the correct orientation. then I discovered the fuel pump gets power from merely jumpering the two female position 87 slots together. it would be nice if the other van worked so I could check to see if that’s normal

[wehrbüchse]

[crazyvwvanman]

The purpose of the diodes is to prevent the power from backfeeding from the coil connection to the relay sockets.
If you leave out the diodes or install them backwards the 1 coil connection wire can also power the 2 relay wires and that is a bad thing.
Also if the diodes are installed backwards then the coil connection is invalid from the battery connection and that is a primary test function of the tool.


Mark

[wehrbüchse]

I just fabbed up one of these for use on two no-start 2.1 waterboxers. Maybe you guys can point me in the right direction about my results.

(1) 1st van is being weird. Fuel pump gets no power without the tool installed.

With the tool installed the fuel pump buzzes really loudly. With the inline fuse removed the fuel pump buzzes less loudly, but still louder than one hears in a normal van for a few seconds when turning the key to the on position. To reiterate: even when i disconnect the tool from the batter, leaving it connected to the 87 ports where the relays were, the fuel pump still buzzes loudly.

It's also getting only 7V at the starter.

(2) 2nd van belongs to my kid & has been the bane of my existence for 1.5 years. I spend a month on it last summer, a couple weeks this past spring, then finally surrendered & took it to a well reputed VW mechanic who conducted all the same tests I had already tried last summer before he too gave up and charged me 1k to hand backs keys to a non-running van.

I was very hopeful the tool would help me figure this out. Still won't start. Van gets spark and has 32psi on the fuel tee. It just turns over & over but will not start. Maybe someone can help me remember what possibilities this leaves.

[shizam]

Doh, "the empty", I swear I read that sentence several times but totally missed that. Thanks, RIH!
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`91 Syncro Camper