Electrical needle in a haystack - fixed but why

start
electrical-wiring
intermittent
golf
volkswagen

#1

First let me say after extensive testing and replacement of the starter/solenoid, a relay, and recharging the battery, the car is running today; however, I’m not sure why.



1) The problem started when I was driving. One second I’m driving and the next there is no power at ignition switch (ON or START); like a light switch going to off. And after I got it home, the car acted like this: when the ignition switch was turned to the ON position, the instrument cluster had power. When it was turned to START position, the cluster went dead. It started once, got five feet and powered off again.



2) I have the Robert Bently Service Manual. I used this to test the various components and decided the starter and solenoid needed to be replaced. Yet, after I replaced the unit the problem persisted.



3) Then I started a through examination of the electrical system. I tested all the Fuses. I tested the Starter Switch. I tested continuity of the Wires from the Starter Switch to the Fuse/Relay panel. Finally I replaced one of the two relays in the circuit; One is called the Starter Interlock, and the other is called the Seat Belt Warning System. I replaced the first because it is only 12$ and avoided the second because it is 80$. However, these seemed unlikely causes because there was no power. According to the current flow diagram the Ignition Switch gets its power directly (without a fuse or relay in between) from the Fuse/Relay Panel to terminal 15 of the Ignition Switch.



Thats the low down. Operational= T+2



My question, does this behaviour sound typical of any components in an electrical system?


#2

They sure made the Golf for a lot of years


#3

Unfortunately…yes. A few electrical components that act intermittently are neutral safety switches, relays, turn signal flashers and starter solenoids. They can go for days, weeks or months without trouble then suddenly stop functioning. A tap or two and they may work again for days, weeks and months. Sometimes time instead of taps will get them working again which is even more frustrating. Any electrical component with contacts can fail and then start working again on the next try. Sometimes it’s a very small needle in a very large haystack.


#4

Check the ground wire from engine block to the frame/fender/body. The body end may have to be removed and cleaned. It’s just one possible cause but it can make a lot of parts go part time.


#5

If the other comments don’t help the i have something you can check. I call it the silent slip. I have an old honda and it did the same thing you described. It turned out the my alternator belt was bad but it didn’t make a sound when the belt was slipping. Therefore as the battery ran low the instrument panel would shut off which only took 5 or 10 seconds from the time the belt began to slip. Following the instrument panel shut off the car will die but the problem is disguised by another strange glitch, as the car died the belt catches just long enough to give the battery a small charge allowing the car to start again only to repeat the same way over and over. I changed the belt and checked the tension and the problem was gone. The belt will not always slip because of many factors such as temp, moisture, or discrepancy in idling and revving.


#6

Why didn’t you suspect the ignition SWITCH? Notice the word SWITCH in the name of this component. As missleman said, any component which has contacts, can be intermittent; and the ignition switch certainly has contacts.


#7

I was hoping to find a specific answer would suggest a typical problem with the divided operation of the switch. I’m not finding that answer and it suggests a more through examination of the components. There is a fault in the seatbelt warning system at the seatbelt (contact that confirms the seat belt is connected); however, this is only an issue when the car is started, not after it is running. I was thinking of jumping the wires to take the seatbelt switch out.


#8

This trouble has nothing to do with the starter system, as you found out. The trouble you are having could very well be due to a problem with the ignition switch so checking the power into and out of the switch while the trouble is happening would verify if it is at fault or not. Most vehicles supply power to the ignition switch from a wire tied to the battery that supplies power first to a fuse panel under the hood. Fused circuits from that panel then supply power to the ignition switch and also to other accessory circuits. There could be a fusible link involved for the power to the ignition switch. This trouble could also be with the wire that supplies power from the battery to the panel under the hood. The battery could also be at fault due to a intermittent connection inside it. Tapping on suspected trouble areas may show the problem up.


#9

I think you already fixed the problem when you replaced the relay. Yes, the ignition switch gets its power directly from the fuse block, but it then activates that relay to start the car. If the relay had some bad contacts it could easily cause a no start condition. Now, the total loss of power might also have been the relay. It depends on how the power to the instruments is routed. Many cars have a relay that the ignition switch energizes to turn on lots of other things. I don’t know about your car specifically, though.

Also, as others have said, you might still have a bad ignition switch.