Topic: '72 350F Wiring Problem - SOLVED (Kind of...)

[Dr. Frankenstein]

I'm using the OEM wiring harness in this 1972 350F I'm working on, and while I had the main harness off the bike I cleaned and tested all the connectors and plugs for continuity and they all tested good. Put the harness on the bike with a 13.10 volt (fully charged) battery, turn the switch on and got nothing anywhere. No lights, no dash lights, turn signals, etc.

I Jumped the solenoid and she cranks fine, so I'm suspecting a bad solenoid, even though this one was new out of the box but it's been a while since I received it. It's just been sitting around but it's not rusty or anything, it looks brand new, which it is...I have continuity through everything in the harness up to the headlight bucket so I know everything is getting a signal, even the R/Y wire and B/W wire - but a bad NEW solenoid?? I know it's possible, but am I missing something else??

I have a battery ground from the Negative post to one of the big bolts on the frame, a Positive wire from the Battery Positive to one of the solenoid posts, and even that little two-prong plug off the Positive solenoid post attached to it, and another wire from the other solenoid post to the starter....so what do you think...? Bad solenoid??

[scottly]

The solenoid is only for the electric starter, not the lights etc. Is there a red wire from the harness attached to the solenoid post that's connected to the battery +?

[Dr. Frankenstein]

Yes, it's in a two-pronged plastic connector that houses a red wire and a red/white wire that connects to the Positive post; I also put my VM on the starter bolt and touched the other probe to both solenoid posts and got continuity...I have a wiring diagram I'm working from too, but obviously I'm missing something b/c I have no lights, signals, Nothing.

Possible clue: the four wires coming off the key switch have all been 'repaired' by the PO with those long ugly blue plastic crimp-style connectors - the key switch itself is new, and the wires do match up - but I took off the key switch connector and tested the repaired wires with the matching wires in the bucket and got continuity there, too...

[scottly]

Don't bother with continuity tests, check for voltage, with one meter lead on the battery - terminal. You should have 12v on the red and red/white at the solenoid post, then on both sides of the main fuse, and then at the red wire at the key switch. The key can be off for this part.

[Dr. Frankenstein]

With the lead on the Positive terminal, or Negative? (I suck at diagnosing electricity...)

[scottly]

Place one meter lead on the battery neg, and probe the different points with the other meter lead. BTW, there should be a solid green wire from the harness with an eyelet that gets grounded to the frame somewhere.

[bryanj]

Neg lead of meter to neg of battery.
Engine end of ground lead needs to go to an engine mount bolt where the frame paint is removed so the wire connects direct to frame and engine.
There should also be a small ground wire, on 500 its by the coils, that also needs to go direct to frame not paint

[Dr. Frankenstein]

Yeah, that green wire gets grounded through one of the eyelets on the filter box...at least that's where I found it; I'll double check, but I'm pretty sure I have everything grounded to bare metal. I'll check for that little ground by the coils too.

UPDATE: The good news is I did have 12Volts at all those points you mentioned and then turned the bike back on and (with apologies to Viktor Frankenstein) "Alive...ALIVE...It's ALIVE!!"
She cranks and I have spark too! 

Well, she's 'waking up', anyway. All the lights work, Hi and Lo beams are good, and all the turn signals work EXCEPT the right front! It 'works', but it's not blinking, it comes on steady. All the other signals are blinking when I hit the turn signal switch, but the RF comes on and stays on, and the Right Rear signal works/blinks as well. I tried cleaning the RF turn signal contacts and ground, switching the RF wires with some of the other green wires around in the bucket, especially where the left signal wire goes into, but it doesn't want to cooperate. I do have a wiring diagram and was following that, too, but no cigar.

I'm thinking it's a ground somewhere in the RF blinker, but I don't know where; the bulb is good, and the (new 12 volt) flasher works as evidenced by the other signals flashing, but the RF stays on...and I suck at electricity, so...what could it be??

FURTHER UPDATE (Because I'm an idiot):  I went back in and was puzzling over why my RF blinker wasn't blinking, staring at the black wire coming off it with the nifty little light blue collar on it plugged into a black wire lead, and Common Sense came up and whapped me in the head...it wasn't blinking because it needed to go into a LIGHT BLUE connector. I changed it out and the angels sang.  To be fair, the light blue connector had another female connector going to it, and that one was buried behind the one that I could see and thought it was only a single connector. (Insert Homer Simpson's 'DOH"! here... )

BUT...! I now have everything plugged in and working, but now the turn signals are running slow...wtf??

I'm about as sharp as a pound of wet leather when it comes to electricity...

[Bodi]

Signal speed with a stock flasher is relative to lamp load. More load amps = faster flash. I don't recall what the OEM bulbs were, but USA standard car bulbs are not an exact replacement. Or replace the flasher it may be tired. Usually 1156 single and 1157 dual filament bulbs do pretty well. LED bulbs, even on one end, won't work well if at all with the original flasher.
Best is a 3 terminal electronic flasher, beware that there are several types and some are just fuse testers if tried in our bikes. Sorry I can't find the part number that works. Look for one with a terminal numbered 30 or 31 for ground. Some (many) have a second power (87?) out terminal that - when plugged to your green wire, just blows a fuse.
Two terminal electronic flashers all "start" with the bulbs off, and after a half second or so turn on and start flashing. Three terminal ones start "ON" then begin flashing. I do not like that half second delay. (electromechanical flashers like the OEM one all start "ON")

[scottly]

BUT...! I now have everything plugged in and working, but now the turn signals are running slow...wtf??

I'm about as sharp as a pound of wet leather when it comes to electricity...

Is the battery run down from all the testing? What's it's voltage with the key on and the signals working?

[Ozzybud]

These work great on all my bikes and are relatively inexpensive.  Under $9.00
Plus they clip on to the factory bracket.

[Ozzybud]

Link

https://ebay.us/m/CdkANU