74 Super Beetle Won't Start

[MichaelRecycle]

I have a ’74 Super Beetle which runs great but has a quirk— sometimes it doesn’t start. I put in the key, turn it, and the oil lights turn on and the seatbelt buzzer buzzes. Nothing else. No other sounds. It seems completely random. Lasts for a few days, then all is normal for weeks until it happens again.

It reliably starts with a push-start when this happens. I thought it had to do with humidity and the old wiring, but that theory’s been disproven. It’s not the battery or the starter or the ignition switch— here are some things I’ve verified or checked:

- New Starter
- New ignition switch
- New battery
- Solenoid is good
- Seatbelt warning system has been disconnected.

Voltage looks good everywhere on the meter. Through trial and error I’m convinced there’s a loose connection somewhere. But where?

I’m a newbie, and this is my first Beetle. I’m learning as I go, but this one has me stumped. I’m hoping someone here has some advice. Here are some photos of my underseat compartment— what am I missing? Am I looking in the wrong place?

Thanks in advance!

[bomberbob]

Voltage regulator looks OK visually, its not your starting problem anyway.
- Those red larger gauge wires jammed together - they need insulated, and I can't really tell how they are mated. That should be the wire going from your ignition switch, to your starter solenoid.
- That wire with the short section of brown wire should go somewhere, unless its for your seatbelt warning.
You might be a good candidate for a hard start relay.
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1968 Beetle (storage)
1990 Jetta GLI megasquirted, burning E85 (currently in heavy maintenance)
2004 Jetta turbo GLI
Marion, Iowa

[laststarfighter]

I had the same problem. Last month my local VW mechanic fixed it by putting in a hard-start relay kit. Just type that in Goggle and many sources such as Appletree, J bugs. I think mechanic said also at local parts house. Totally fixed the issue. Located the relay under the back seat.

[MichaelRecycle]

Thanks, all.

A hot start relay was put in last fall, but the issue persists. I'm stumped. The unplugged wires in the photo are for the back defogger, which is disconnected. I've now cleaned and insulated all my terminals, but of course the issue stopped before I did it!

I guess only time will tell...

[cricketseed]

I had the same problem for years with my '74 Super thirty-something years ago in high school. I wish I could tell you how I eventually fixed it, but the sad truth is that I never did. (No internet back in those days, mind you, and neither my stepfather, my stepbrother, nor the local VW shop could figure it out.) I did get pretty handy at crawling up under it to short out the starter with a screwdriver. That worked every time, but it didn't exactly make me or my car any more attractive to the opposite sex. Now that I think of it, that car had a laundry list of problems that likely could have been fixed in a weekend if YouTube had been a thing back then. Good luck.
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'66 Beetle

[VW_Jimbo]

Sounds like a cracked ignition switch. Common issue. And the bitch is that the aftermarket switches are horrible!

Good luck!

Oh, there are 2 parts to the ignition switch. There is the lock cylinder where the key enters and resides in, beyond that, on the front side of the assembly. (Front of the car, you are looking at the rear of the switch when sitting in the car) The electrical portion sits in the front spot. It all has to be disassembled to gain access, no short cuts!

Back side of the electrical section.

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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[OTTO 1303]

Don’t want to get you to chase your tail, but if the problem is intermittent, and all of your connections in the circuit are clean and fit snuggly, take another look at the ignition switch, both electrically and mechanically.

Good Luck
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74 Super Sun Bug - OTTO
74 Super - DANZIG
74 Super - HERZOG

[olorin67]

My 74 love bug has similar issue, about one start in 25. I’ve tried jiggling ignition switch but that doesn’t have any affect. Several times I’ve gone in the house to get my wiring diagrams to have it start right up when I get back to the car. I’m thinking sticking relay maybe. Or maybe whatever was done to bypass the 74 seatbelt interlock isn’t making good contact. I’m going to put in a remote start button to help troubleshoot. And apply deoxit to every connection. Doesn’t seem to be sticking starter. And when it happens I don t get any relay clicks. For now I’m just careful where I park in case I need to push start it.

[olorin67]

It looks like your electrical connections are fairly oxidized, might want to clean those up. Deoxit works well.

[runscx]

I'm not saying this will solve your problem but I noticed if I limp wrist it when I turn the key it might not turn the crank for the engine to start and it will just make a hissy click sound.

If I turn it like I stole it that bad boy starts every time

[EXJAY]

Working the same issue right now on my 74 SB. I'm only getting 6ish volts to the starter when attempting to crank. Traced the red w/black tracer wire back under the dash through a connector then goes to behind the fuse block to a relay. When I turn the key still get 6v under the dash and I know the wire from the dash to under rear seat is good. Removed the relay from behind the fuse block, saw signs of rust on a few pins. Opened relay and found components appear ok but the circuit board they are all attached to is heavly corroded. I'm assuming this is my issue at this point and the ignition switch seems to test ok. Will attempt to clean up the board and test. Anyone have a source for replacement if needed?

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EXJAY

'74 Superbeetle (Family owned since new)
'73 181 Thing (sold)

[VW_Jimbo]

That looks like the Seat Belt Interlock Key Buzzer Relay. eBay has several for sale.
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[EXJAY]

[EXJAY]

Installed a relay from Advance Auto as pictured in the hard start relay wiring diagram and the fixed my no start issue. Bypassed/eliminated the seatbelt starter buzzer/relay under the dash. Thanks for the input.
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EXJAY

'74 Superbeetle (Family owned since new)
'73 181 Thing (sold)

[ashman40]

In '74 and some early '75 model year Beetles the Seat Belt Interlock relay interrupts the #50 starter solenoid circuit until all occupied seat belts are fastened. When the relay fails the circuit between the ignition switch and started solenoid can be left open so the starter no longer functions.

Remove the solenoid and test the "C" terminal on the relay bridge (not on the relay) for 12v while the key is in the START position. Test it 10x and make sure there is 12v each time. If this works fine, add a jumper wire between the C and 50 jacks on the relay bridge. This bypasses the Interlock relay and directly powers the starter solenoid (or hard start relay) from the ignition switch.
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AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}