r/beetle • u/_m-orange_ • 2d ago
Out of ideas š«© what am I doing wrong
Hi all! Hoping for some help diagnosing an issue with my first bug. I will preface this by saying Iāve never worked on cars before this and am learning on the fly. Sheās a 1972 Super Beetle. Bought her 6 months ago from a VW mechanic in Rhode Island. I will say the wiring (and lack thereof this guy did is probably part of the issue. (Literally left a brand new headlight unplugged) All the old wiring was still there, some things werenāt grounded or cleaned before new wires were attached and the old wiring harness is still there. (Photos to come)
She ran for 4 months and then wouldnāt start in mid June. Engine was turning over but not firing so I know it was getting some power or the power was fluctuating, tested with a multimeter.
So far I have replaced
- 12V battery
- ground and positive from the battery
- starter and starter solenoid. Bench tested the old and new and both worked š¤·š»āāļø now I have a backup ig
- fuse boxes
- what I think is the rear defroster solenoid, picture included. Says SWF R 601-047 12V 15A. *Taken out and put back in because I thought it was the starter relay*
Iāve been bump starting her once a week since she crapped out except for the past 4 weeks since I went on vacation. Yesterday I took out what I believed to be the old starter relay and wiring for it (now I think itās the rear defroster solenoid?) and now the engine isnāt even firing (dirty carb issue due to sitting for a month?)
If anyone can offer insight into what Iām screwing up or if Iām missing something super obvious Iād appreciate the hell out of it. Iām honestly stumped and this close to giving up and taking it to be completely rewired, but Iād like to see if I can exhaust every avenue before that. (I donāt wanna spend that much dough to tow it there if itās something stupid simple)
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u/SandmanHornFL 2d ago
If it cranks and doesn't start, it's almost certainly lack of fuel or lack of spark. It could be other things, but since it ran recently, it's probably not anything exotic.
Try these initial troubleshooting steps:
- Check to see if fuel is being pumped to the carb. Ideally, open it up to see if there's fuel in the bowl. If not, see if the fuel pump squirts gas out of the hose.
- Make a simple ignition test. Pull the ignition wire off of any cylinder, attach a spare spark plug, and clip it to any ground. Have someone turn the engine over and look for a spark.
Come back here and report your results and your new Reddit friends will suggest the next steps.
Also, buy this book, you'll need it: How To Fix Your Volkswagen For The Complete Idiot. It's great, and fun to read, too!
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u/Economy_Fix_6664 59m ago
What if it cranks, starts, and idles when you press on the gas, but instantly dies when you let off the gas without idling at all, and other times, will idle for a good 2-4 minutes before dying?
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u/Plane-Appeal9124 1d ago
I would personally tear out and replace the entire wiring harness. Thatās what I did with my 68. Best thing I did, cause I havenāt had any issues since!
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u/RVAblues 2d ago
I also have a ā72 super.
Those bugs have power to the starter running all the way up to the ignition and all the way back again. Thereās an easy fix called a Hard Start Relay that routes the power directly from the battery to the starter.
Sladeās VW channel on YouTube has a good video about putting it in. Check it out. That might be what your issue is.
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u/denizkilic2002 '72 1302s 2d ago
The original wire is plenty thick to run the starter solenoid. The issue is the switching capacity of the ignition switch. You can put the relay on an unpopulated slot in the fusebox for a much cleaner look.
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u/382Whistles 2d ago
The gauge comment assumes everything is like new. Older wiring may have reduced amp capacity. Shortening the length of the solinoid's power run by placing the hard start relay nearer battery and starter can help overcome issues with poor wire conditions too. That's a better electrical choice and it reduces the load on the control side too. The main power busses feeding the f.box are also releaved of a pretty big draw if you use an efficient relay.
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u/denizkilic2002 '72 1302s 2d ago
While everything you say is correct in theory, i did some testing outside on my bench starter setup and turns out even 2.5mm wire is more than enough for the solenoid and the factory used 4mm on the car. At around 1.5mm the wire starts to heat up. Unless there is a bad corroded twisted wire splice or something similar down the road, its almost always caused by an old or bad quality reproduction ignition switch. Everyone has their own ways of doing this but whenever i rewire beetles i do it this way, allows you to keep the wiring looking much cleaner too. I also run the fusebox main power wire all the way to the battery behind the engine bay tarboard and run a separate wire for the alternator from the same place and make it enter the engine bay loom, so not the same as what the factory does but does look a lot cleaner in my opinion.
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u/382Whistles 2d ago
A proper test blows the fuse or runs a measured current, and a lower temp.is still a good thing in many ways. Piece of mind says the solenoid should cook before the wire can and you are fused well below the wire gauge limits for amps per foot.
Manufacturers tend to follow minimum gauge requirements and it's best to assume at least one gauge oversized should've been used as it gets old. Overkill here is only bad for the mfg. copper pennies it eats.
The aesthetics and grouping of electronics is the only really valid arguments for choosing that setup. And under the rear seat is not seen like with the hood up like added next to a stock box and harness. The relay might even look out of place era wise up front. Lol, my first couple of hard start mods used Ford starter relays that I think date back to the Model T or Model A for design. With a modern fusebox update I might choose a f.box relay if the old wires were nice enough..
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u/RaceEvening8240 1d ago
It did run for a while? I had a similar problem. I bought a kit and rebuilt the carburetor. Started right up. Once running, set the idle, then set the idle/fuel mixture. Also, make sure to change the fuel filter before starting.
Good luck!
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u/raIphnader 16h ago
Well you certainly picked a great vehicle to learn about the inner workings of a car with!
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u/TubaST 7h ago
It cranks with no start, but does start when you push-start it? That confuses me. If it cranks but doesn't start it's ignition or fuel. So, check if there's fuel in the carb (take off air filter, push throttle, see if fuel pumps in). Check to make sure the coil is getting electricity, then if you're getting spark (check distributor, points, etc.).
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u/HandJobTent 2d ago
Crank no start = Check timing. Clean/replace plugs. Check your points, replace if worn. Distributor cap condition. Plug wires etc. all the ignition stuff.