No headlights suddenly

[dgi]

72 510.

 

Having a sudden electrical problem. No headlights. Emergency flashers don't work either, but not sure that is a new problem.

 

Have marker lights, turn signals, tail and brake lights.

 

Also the windshield wipers aren't working.

 

Fuses all good.

 

Any ideas?

[Cuts metal like mad]

fuses may "look" good, but are not always good. Also the fuse box could be the problem. Had a 510 that I'd have to smack the fusebox everytime I drove it in order for the headlights to work, but only had to smack it once. Check everything in the fuse box as well as the fuses and wiring for continuity and it checked out perfectly... oh well one of those quirks.

[DanielC]

I believe your 510 has the ground switched relay system.

Check to see if you have battery power to the headlights, with a test light. If no power, check back at the fuse for power.

If you have power at the headlights, the relay is not able to ground the power from the headlights. The contacts in the relay could be bad, or the wire from the relay to the ground has lost its ground connection.

[banzai510(hainz)]

there is a ground wire by the volt reg ck that also. I have no idea if it will affect it but Daniel C is correct. using a test light power will be at ALL the headlamp plugs. in the OFF position. then when you pull the light switch out a ground will be sent to pass thru the relay and complete the circut. On highs its the same put the turnsignal arm will supply a ground to the relay to trip to supply a DOUBLE ground and route a ground to the HIGHS also.

 

so when a ground is routed your test light be be OFF, cause your test light one side will be grounded. the other side will LIGHT showing your passing 12volts.

 

most relay LOWS work but then go to HIGHS the lights all turn OFF. Most lightly realy needs to be cleaned.

[datzenmike]

You have power to the parking lights so power is there. Check the contacts on the headlight switch. Turn the lights on/off/on/off to shine up the contacts.

[banzai510(hainz)]

Mike

If I remember correctly the parking lights are seperate circut on a 510.

 

this happened to me using a different fuse box then putting the orginal back in as there are different fuse boxes that have the copper thick BUS all connected and some sepaerate in other models tha use a wire that come out which I found out if I hooked to the batter the headlamps worked.

 

if there is power to the headlamps the fuse is good. if bad, trace back ,look under fuse box(maybe broken wire) but most likely its the ground in the realy as that is the mostly like connection that is used. beside the inside light switch.

 

 

sometime just reconnecting the plug and wiggling it around is enough to fix it.

[Cuts metal like mad]

Sorry hainz... but the test light will not show 12v! You know that. It can still light up with 3v or 2v.

[MicroMachinery]

I had a similar problem in my 521, only it'd happen when I switched to brights from dims. Gets pretty exciting when you're on the highway goin' 70 in the dark and your lights go bye-bye.

Anyhow, what I ended up doing was removing the fuse block and cleaning all the connections. You can check underneath it too, and you should be able to see if there's any corrosion(green or white) near any of the contacts, or breaks in the wires. It also wouldn't hurt to remove all the fuses and with a brass wire brush(you can get em at napa for like, $.70) give all the fuse holders a good cleaning, as well as the fuses if none are burned out. Any connections you can reasonably get to without breaking anything, give em the ol' scrub down. Die-electric grease is always a good idea, just to prevent future corrosion, too.

 

It sounds to me light it's your headlight fuse, or something to do with that electrical circuit. I'd start looking there before I began diagnosing a bunch of other systems. Find the point that your headlights and windshield wipers have in common, and work your way back. Keep it simple.:thumbup:

[hang_510]

Anyhow, what I ended up doing was removing the fuse block and cleaning all the connections.

DOUCHE THE BOX

 

 

as well as the fuses if none are burned out.

 

when the fuses get hot the solder connections inside the caps melts and creates more heat.

REPLACE them if they are old!

[yellowdatsun]

Just had a similar problem on my 510. All the fuses were good, but there was just enough corrosion on the fuse block terminals to cause problems. Pull one of the battery cables off, and then clean the fuse block terminals. Would bet this is the problem.

[banzai510(hainz)]

Zuum

but the test light will not show 12v! You know that. It can still light up with 3v or 2v. yes depending on bulb.

 

well depending on the Test Light. I have some that are briter than others. some that planly suck. I have a favorite light now and give the others away.

 

 

sometimes it like testing a battery. Put a meter or light across it it looks good but not enought current to drive it. (load test)

[dgi]

Fuse is good. Checked with test light, have power at the lights. But then it started raining on me, so stopped for the evening.

 

There are two relays on the strut tower facing the fuse box. One has a 6 connector plastic plug. The other has 3 wires coming to it with spade type connectors.

 

Which one controls the head lights?

[dgi]

Resolved the head light issue.... bad relay. Replaced it and I've got lights again.

 

Thanks for the pointers everyone! :)

[Z-train]

No headlights suddenly ?

 

You have been visited by the ghost of "Lucas".:eek::lol: