John Jordan

I recently acquired my dad's 75, I noticed that my front passenger blinker isn't working. I changed the bulb and flasher and still nothing. The weird thing is it lights up fine when the headlights are on. Could it be a ground? Any suggestions would be great. Thanks in advance

MelWff

you used the correct replacement bulb and paid attention to the alignment of the pins on the bulb with respect to the socket?
have you tested the socket with a voltmeter or test light?

John Jordan

Bulb was correct and I believe it went in as intended. I might switch bulbs with the drivers side just to be certain. I haven't tested with volt meter yet.

bj1k

Any time you have a weird electrical problem it is most likely a bad ground , especially with a fiberglass car. Find someplace where you can get a good ground with a jumper wire even if you have to go straight from the battery and run the jumper wire directly to the socket housing . If it flashes find out why it is not grounding. It might just be corrosion.

John Jordan

Swapped out the bulbs and still nothing. Testes with volt meter and it had no voltage when it was on. Ground is probably right. Where do I ground it to in the socket?

bj1k

There will be enough room along side the bulb to reach in with a small jumper wire with an alligator clip on the end to touch the socket side . If it wont fit put a small piece of metal in the end of the alligator clip and just touch the bulb socket housing. If you have power to the center contacts and you know that you have a good bulb then the only thing left is the ground and this test will tell you. You say that you have no voltage when it is on . Are you grounding the voltmeter negative on a good ground ? You might have power and your tester is not accurate because of bad ground.

Rescue Rogers

Same problem in the rear for me, it was a bad ground, the painter painted the housing and didnt scrape the paint off when putting the ground wire on the housing, run a jumper from one of the other marker light that work, look for a ground wire on the opposite side of the car that does work and compare what you have.

If your ground is good the turn signal has a seperate power supply than the running lights, the wire on my 68 is blue, light for one side and dark for the other, yours maybe a different color. Check a wiring diagram and check that wire at the engine compartment fuse block with it flashing, it will flash on your meter or test light, then check again at your connector. You will need a good ground as well

John Jordan

I tested with a new ground and still nothing. It has to be the power supply for the blinker. Can anybody with a 75 confirm what color wire I'm looking for?

John Jordan

I did a little more testing with my volt meter and now I'm getting faint voltage that pulses with the blinker, but it is no where as high as the working drivers side.

Rescue Rogers

turn on your lights and do the same reading. Then turn off the lights and the signal and see if you get a short to ground on the positive side. you could have a bare wire some where that is grounding out (Not likely because it should blow the fuse) or you could be dealing with a bad ground still. Is your reading with the bulb in or out, did you try at the wire block on the fire wall? can you use a jumper to test the bad power side to the good ground on the other side of the car? Have you looked a the rear of the car to make sure your tali lights on that side are blinking too? Does your indicator on the dash work as well. Is it brighter than the other side and is it the same speed or faster?

John Jordan

That was with the bulb out. The rear is working and I haven't tested at the block. My dash light blinks on the side that works and doesn't do anything for the bad side.

Rescue Rogers

With the bulb in you should get the dash light to flash. Try it with the hazard lights, see if the bulb will go into the socket 180* out, Don't force it. The power should be the same if your getting any so that is weird. It would be lower on the meter if the meter wasn't grounded. Usually if you have a bulb out, the flasher on that side hyper flashes. I don't know if you have a printed circuit behind your dash but that could be an issue if you do. You need to trace your power back to where it is normal 12ish volts. I would disconnect the harness at the firewall and check your wiring for a short from the block to the plug to eliminate the wiring up front. If its fine then you may have to check behind your dash. In my car there is 2 flashers, one signal and one hazard. So if something is bad in the wiring, both would be bad, you may have a switch problem in your column as well. If both indicators don't flash with the hazrd light s you might ahve a bad indicator bulb

Just dont get overwhelmed, go slow and check back towards the console. Both sides use the same power so if you get a wiring diagram and map out where it comes into the harness and where it seperates left and right you should be able to find the area to check. you say the rear works, is it asa bright as the other side and flashing at the same rate? what happens with the hazards.?

John Jordan

Tried it with the bulb in and ran an extra ground to the working side, still nothing. Emergency flashers didn't change anything and my dash indicator didn't come on with the bulb in and emergency flashers on.

SwampeastMike

Doesn't sound like a ground problem to me.

While this assumes that the dash indicator bulb is good two possibilities are:

1) Dirty or not fully seated "harmonica" connector. The harmonica connector is on the underside of the steering column. I don't know what (if anything) you have to remove to access it in a '75. The name comes from the shape so it's very easy to identify. I'd suggest disconnecting, cleaning and reconnecting.

2) A faulty turn signal switch.

Rescue Rogers

its sounding more like a problem inside your switch, can you get at the wiring for your turn signal switch on your steering column, check the power there. Use your wiring diagram to check what wires go where. There are free ones available here on the forum, do a search, they are black and white so you'll need markers to colorcode them if youre like me

SwampeastMike

Another thing--can't believe I forgot to mention this as it just happened to me.

Trace the wires going back from the bulb to see if they go to a connector close to the harness. If so, disconnect and clean-clean-clean with a wire brush. This will probably entail removing the terminals (particularly the males) from the connectors. Do a search for how to release Packard 56 terminals. If you can't remove the female terminals, you can run sandpaper between their contacts to clean.

Despite their location these are not weather resistant connectors. I undid mine as part of other work and only did a cursory cleaning. When reconnected they would not conduct enough electricity to operate properly.

BUT, the dash indicator would still be flashing (or more likely on steady) if the lamp is good.

John Jordan

I was able to wedge myself under the dash and I used my test light on both ends of the harmonica connector. The good news is it lite up on both sides ofnthe connector, so the issue has to be between the harmonica and the bulb

Rescue Rogers

it should have 1 place for each light. did you check it against a wiring diagram, it should be flashing after the flasher as well

John Jordan

I was playing around with the connection at the firewall and boom the blinker started going. I'm so happy to see that little light going. I'm going to keep cleaning. Thanks for all the help.

Peterbuilt

With the key ON and the turn signal lever UP (as to make a right turn) see if you have 12 volts at "J".
!2 volts go up the steering column and moving the turn signal lever sends power the bulbs.



75 schematic.
https://docs.google.com/viewer?a=v&p...WRiNTdjNjdkNTQ