Blinkers - Fuse Blown

[steenh]

I need some electrical guidance. Search didn't help with this problem.

1967 stock wiring.

Problem: Blinker fuse blows when I turn the key. Engine starts (not wired through the fuse) and all other electrical functions work as they should.

I also have two gauges that work off that fuse, Tach and Temp (stock wiring except for that). If I detach the blinkers from the fuse box, and keep the gauges attached, no blown fuse, and the gauges work. If I detach the gauges and attach the blinkers, fuse blows.

What I've done: cleaned up the fuse box. Replaced the flasher. Checked all grounds. (don't think that's the issue since fuse blows). Tried to remove the flasher (grasping at straws). The symptoms haven't changed at all... blown fuse.

What I need: Just a direction to look. I have a tester, but not sure how to use it if I have no current due to blown fuse (but I'm not an electrician and could be missing something on that). Am I really down to tracing all the wires and looking for a short?

Thanks much for any guidance you can give me!

 

[Pin_Head]

What I need: Just a direction to look. I have a tester, but not sure how to use it if I have no current due to blown fuse (but I'm not an electrician and could be missing something on that). Am I really down to tracing all the wires and looking for a short?

Thanks much for any guidance you can give me!

The direction to look is downstream (toward the lights and ground) from the fuse that blows.

The first step is to look at the schematic diagram for the turn signal circuit. there is one in tech links for a 71 that will be close enough. Note the color code of the wires and that the power goes from the fuse to the flasher, to the center pole of the signal switch, then to the L and R sides.

I believe that you already know an important clue: It blows without the turn signal being activated either L or R. If so, the short is before it branches L and R at the switch.

Remove the flasher first and see if the fuse blows. You can use your light bulb circuit tester in place of the fuse if you get tired of buying fuses. Connect the alligator clip to one side of the fuse holder and touch the probe to the other clip. If the buolb lights, you still have a short. If the fuse no longer blows after removing the fuse, the short is after the flasher. This points to the switch itself, which is the most likely problem since it is subject to wear.

 

[WES1977]

I had a problem the other day somewhat like that I guess. I was cruising around no problems and a cop pulls up behind me and turns on he's blue lights. So I put my right turn signal on and my cruiser died and backfired and was running ruff. So the cop tells me how I don't know the law about Antique tages and such and tells me i'm not supposed to be joy ridding my cruiser. So I agree with him and he let's me off the hook. But he is keeping an eye out on me.

Ok my cruiser cranked right up and ran great. It was about dusk so I turned on my lights. It was running bad again, I barely had enough power to get out of the intersection I was making a left turn at. I pulled in a parking lot and could not find anything wrong. Cranked it back up and ran great until I turned on the lights. So I drove home with no lights on and It would run bad with the turn signals on also. Got home disconnected the Front turn signals one at a time and found it to be my right front turn signal bogging it down. Reconnected it and insulated it and now good to go.

I guess the meaning on the story is to isolate it down one item at a time.

Oh yeah the Cop is wrong. I can take my antique out for "occasional pleasure rides". So now I have a copy of the law from the police site in my glove box.

 

[steenh]

Thanks!

I have a cupfull of blown fuses now!

I have tried pulling the flasher and the fuse still blows. If I understand correctly then, the short is BEFORE the flasher then and points to the problem between the fuse box and the flasher itself? If that's the case, this may not be that difficult to hunt down.

Is that a correct assumption?

Thanks again!

 

[Volunteer]

It funny I'm going through the same thing on my 67, but not for the same reasons. I just replaced the turn-signal switch and turn-signals because the PO put on some aftermarket turn-signals not of Land Cruiser origin and they did not work. So I changed the turn-signal switch and put on OEM turn-signals. Well after cleaning up some of the PO wiring patches I got them to come on just fine but hey don't blink. I traced wires over to the flasher and found another hack job going to the flasher. Going to pick up a new flasher and clean up that wiring tonight. If you need color codes or location of wires let me know I may be of help. I think you have scared wire somewhere in the dash shorting you out. I didn't print the wiring schematic but it was so simply laid out compared with the cars now. I just laughed and went on dancing around with my test light. I had some scared wires also as I was cutting out wire the PO had in there, I taped it up and put it in loom. On mine the wires are tight against the top of the clutch and brake pedal bracket under the dash the harness was rubbing on that bracket scaring the wires. On the fuse panel its the last fuse on teh bottom, but should only be hot with the ignition is on. If its hot with the key off, someone might have taped into that wire causing your short. Good luck, if I can help with pics let me know.

Larry

 

[Pin_Head]

I have tried pulling the flasher and the fuse still blows. If I understand correctly then, the short is BEFORE the flasher then and points to the problem between the fuse box and the flasher itself? If that's the case, this may not be that difficult to hunt down.

Is that a correct assumption?

Thanks again!

Sounds reasonable. Shorts can occur at the fuse block itself, so if it isn't the wire, you may have to remove it and see if anything is grounding to the chassis.

I got them to come on just fine but hey don't blink. Going to pick up a new flasher and clean up that wiring tonight.

The reason they don't blink is that the circuit doesn't sink enough power to heat the bimetal switch in the flasher. This is usually an indication that there is a bad connection somewhere or bad ground. It could also be due to running a low power bulb, like LEDs. An electronic flasher will force them to blink but it may be a band aid for a bad connection.

 

[steenh]

Update.

Over lunch I went home and tested. Took off the line that ran to the flasher, ran a separate line and sure enough, no short. Put in a fuse and blinkers worked. Thought that was the end of it until I realized that there were two wires coming from that connection at the fuse box. Unhooked the flasher line and tested again with just the other line attached. Shorted out. Looked at the wiring diagram and turns out that the blinker line was fine. It's the wire to the alternator regulator that is shot somewhere. Short line to run so all's good.

Easy change tonight and I'm back in business.

Pinhead, Volunteer, thanks a lot... doubtless saved me hours of time. In fact, took me about 15 minutes to figure it out.

Love this board!

 

[steenh]

More help please

Thought I had it figured out but not quite.

I rewired from the fuse box to the generator regulator... the line that I know is causing the short since wiring just the blinkers worked. As soon as I plugged in the new line, the short reappeared.

Is it possible that the regulator itself is shot causing the short... or does that just tell me it's downstream? From the regulator, there is a line to the alternator. I unplugged that and rechecked the short... still there. I can't tell from the wiring diagram where the wires from the regulator go other than the alternator.

Any ideas? And a noob question... what does the regulator do (besides regulate)

Thanks!

 

[Pin_Head]

Is it possible that the regulator itself is shot causing the short... or does that just tell me it's downstream? From the regulator, there is a line to the alternator. I unplugged that and rechecked the short... still there.

Yes, this indicates that the short is upstream of the alternator. Unplug the white wire with red stripe at the regulator. If it doesn't blow, then the regulator is the likely culprit. If it does blow, then the short is in the white/red wire. Start following it back to the fuse block and check every place is crosses the chassis metal.

 

[steenh]

OK. I rewired to the regulator... unplug it and no short... plug it in and it shorts so it's the regulator then. Is that a part I can get at autozone, or special order?

Thanks,