Electical problems with random no start.

[JQ]

1970 hardtop westfalia with 1600cc motor. I had her sitting for about a year and a half while I replaced my transmission and did other work on her. I got her back on the road again recently and I'm having some tricky electrical problems that weren't there when I parked her. First off, sometimes (very rarely) as I try to start the motor the key turns all the way with no reaction from the starter. Battery is fairly new and good condition with a full charge. While she was parked I took apart the starter and solenoid, cleaned it, regreased, and reassembled. The majority of the time it starts and sounds just fine but when it doesn't I either wait a little bit and keep trying and then eventually it will turn over. I have also used a portable jumper pack to give it a little boost and surprisingly that works as well. Also after I start it once the problem goes away for a couple weeks and then come back randomly, as is first thing/cold start, or after I drive and park and try to restart. Is this an ignition switch problem starting to develop or a starter/solenoid issue.

Next, my oil pressure gauge worked fine before but now the warning lamp stays on and the gauge doesn't move. I know for sure I have oil pressure and shes been driving great so I doubt it's that. I bought a new replacement VDO sender because I thought my old one was bad but same thing. I even tried using the stock single pole sender and the light still didn't go off. Ideas?

Also, my turn signals seems to work whenver they feel like it and the light on the dash will flash a couple times and then stop or not at all. Is the relay in question here?
I did no work electrical work while she was parked and all these things worked fine before making me believe it might be a corrosion issue at some of the terminals and I have tried cleaning them up but it would be nice on where to look before I wire brush every connector.
Thank you,
JQ
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1967 Bug aka "Junior" (SOLD)
1970 Campmobile aka "Penelope the BEAST"

[timvw7476]

The first two issues, I'd check the ground strap, trans to body & the
ground surface for the negative battery cable, the turn signal issue,
check the fuse, actually clean all the fuses, they like to corrode at the
contact surfaces at the ends and stop current flow.
I doubt Vacaville gets too moist, but you list S.F. too, so...moisture
& change-of-seasons. Contact point cleaning time.

[Amskeptic]

[SGKent]

the most common starter no start failure is a sticky solenoid. That said, you want to be sure every connection is clean and solid like the last two posters suggested. A common quick test is to have someone turn the key for you and tap the solenoid with a wrench, hammer or screwdriver. Notice I said tap not hit. If that makes it kick over the grease inside it has hardened. I went thru this faithfully on a near new 1971 VW bus for 400,000 miles once every couple years while I owned it depending on miles driven and how long it sat.

As for oil pressure, I would insert a mechanical gauge and check again. The light and gauge are two separate circuits, and you have tried 3 senders. That would deeply concern me. Making matters worse, the light won't come on unless the engine block is grounded so if that had no ground the light would not work. You can pull the wire off the sender and see if the light goes out. If it does then don't drive it until you check for oil pressure with a mechanical gauge. Does it have oil in it? Are you sure?
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[JQ]

[SGKent]

pull the wire off the sender and see if the light goes out. If it does you either have a rash of bad senders or low oil pressure.

Have you checked the screen to be sure it is clean?
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[JQ]

[airschooled]

Check the oil level too. Once my engine consumed a quart in 250 miles. It never did it before, or after. Well, except that one time it blew the oil cooler seals… Then it dumped it all in 250 feet!
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One-on-one tech help for your Volkswagen:
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[airschooled]

[busdaddy]

[airschooled]

[telford dorr]

The only way to accurately diagnose a starter issue is with a voltmeter. You need that, and a pair of test probes which have clips on the ends.

- Connect the meter from the small starter wire from the ignition switch (still connected to the starter) to engine ground. Have someone try to start. Watch the meter. If it reads near battery voltage, then the solenoid is getting power but not doing anything with it. Repair / replace the solenoid.

- If the voltage is low, then move the meter ground to body ground, and try again. If the reading is normal, then it's the tranny ground strap.

- if it's still low, then move the meter ground to the battery '-' terminal and try again. If the reading is normal, it's the battery ground cable or its connections.

- If the reading is still low, move the meter to the ignition switch. Red probe to the red/white starter wire, black to body ground. If the reading is normal, then it's the wire to the starter or its connections.

- If still low, move the red meter wire to the red supply wire to the ignition switch. It should read 12 volts immediately. Try to start. If the reading stays steady, it's a bad switch. If it drops, keep tracing the red wire back to the fuse block, headlight switch, and eventually to the battery '+' terminal. Somewhere the voltage will stop dropping. The problem lies between that point and where the voltage drop is measurable. Inspect, find, and fix.

Note: it is typical to find and fix one problem only to find it then occurs somewhere else. Keep finding and fixing. The practice will do you good the next time the horn quits...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[SGKent]

[telford dorr]

Hence the long-winded tutorial...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[mikedjames]

Just to add to the solenoid story - I had this intermittent non-starting problem on my bus . And at the same time I also had a defective ignition switch.

Some times the starter did not engage even with 12v direct on the tags on the back
Other times not even 12v on the starter.

So the resolution was a new ignition switch (although stripping down the old switch, collecting springs and ball bearings in the dark with a big flashlight from the driveway, cleaning and reassembly worked for a while)

And because I could not be bothered, a reconditioned starter motor.
_________________
Ancient vehicles and vessels

1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[telford dorr]

A multiple failure like that doesn't surprise me. If the solenoid fails to pull in, it will, due to how it works, draw a huge amount of current. This huge current will slowly destroy the ignition switch.

Cascade failure...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)