The turn signal module is unlikely to be an issue. If it has split flat-side tanks, the TSM/canceller is actually located under the dash, in-between the two halves of the gas tank.

The box you're looking at is the fuse box. The voltage regulator should be at the front of the bike, between the down tubes. I'm attaching a pic of the regulator for you:

As to fixing the rear turn signals... the taillight still works, right? Also, if you press the turn signals, if the rear isn't working but the front is, the front should flash at double speed. As stock, the rear turn signals (if there's a center tail light) are a single filament 1156 bulb. I double check the contacts with a volt meter with the turn signal set to flash and see if you see any changes.

The bike has the stock incandescent bulbs, right? Like it hasn't been converted to LED lighting?

 

Thanks much for the reply!

Yes, the bike has stock incandescent bulbs. I put new 1156 bulb in both rear turn signal sockets. Sockets and contacts are nice and clean.

Yes, the tail light works. Yes, the front turn signals are working, but I have no reference regarding speed until Tom gets home from work tonight. (I'm retired, so I was looking at the bike by myself earlier today.)

I did find out that the large black relay I took a picture of in the fuse box is the starter relay. (Still don't know what the module in front of the rear fender and behind the oil tank is.)

It does have split tanks, but I haven't looked in there yet. Likely not the turn signal module anyway per your post.

I'll take a VOM over there next time and check the turn signal sockets to see if I'm getting voltage with the turn signals set to flash.

Thanks again for your help.

 

I dunno what that module is either. The only thing stock that should be on that rear fender extension on a 1997 softail, is the 30 amp breaker for the starter, which is a small thing with two prongs on it, one copper or brass or whatever and the other silver. One side of that breaker has a wire that goes from there to the starter, and the other side should have a wire from the voltage regulator and another wire I think that goes to ground (not entirely sure, I don't feel like grabbing the manual). In the pic you posed, you can actually see it to the left of that box. Anyway, that breaker is about as big as the end of your thumb, it's not a big huge box like that. Though, a Heritage might have something else there on that fender extension, I dunno, but I don't remember seeing anything about it in the manual. Do you know where those wires go that's coming out from underneath it?

Anyway, I'm not saying the problem can't be the TSM/canceller, but it's unlikely. I also have a 1997 softail, so I know it a little, they're mostly all set up identically as far as electricals and most stuff is all in the same locations, a few minor differences here and there between softail models.

The TSM should be, when you take the dash off, right below the upper tank mount bolts. There's a procedure for testing it in the factory service manual, I don't know it off-hand though.

Another thing to check out if the wiring looks good, is the plug itself. When you take the seat off, you should see an 8-place multilock connector to the right of where the ignition control module would be.

 

Thanks so much again!

I couldn't really see where the wires from that unit on the fender go.

But, I actually think we found the issue. That connector you mentioned just behind the battery on the right side of the bike FAILED the wiggle test! We wiggle that connector and the wire harness it's on and the turn signals come and go!

So, it's inside that connector or a wire in that wiring harness really close to the connector. So, we found it. Yay!

Another question for you. There is another connector just like that one but on the LEFT side of the battery. It has nothing connected to it! Tom says as long as he's had the bike it has never had anything connected to it. Do you know what this unused connector is for. Here's a picture of it.

Thanks very much for your help. Gotta love forums!

 

The front and rear turn signals are on the same circuit (a circuit for each side).

If the front signals flash, the problem is not the TSM/TSSM.

The problem is there is an open somewhere in the circuit.

Check the connector for the rear harness that goes back to the tail light/turn signals, and also check the wires between the connector and the tail light/ turn signals.

 

The front and rear turn signals are on the same circuit (a circuit for each side).

If the front signals flash, the problem is not the TSM/TSSM.

The problem is there is an open somewhere in the circuit.

Check the connector for the rear harness that goes back to the tail light/turn signals, and also check the wires between the connector and the tail light/ turn signals.

Thanks Dan. We found the problem!

The connector you mentioned located just behind the battery on the right side of the bike under the seat FAILED the WIGGLE TEST! We wiggle that connector (and the wire harness it's on) and the turn signals come and go!

So, it's in that connector or the wires very close to it.

 

Go ahead and get some dielectric grease too and put it inside the connector before you guys put it back together. Will keep out water and prevent corrosion of the pins.

 

Spray faulty plug with CRC electrical cleaner dry and put dielectric on it, plug back together probably odds be working again. Old bikes anodized contacts.

 

Curious if that fixed it, I have a 98 and every electrical connector I get my hands on I do that process as preventative SOP, and those pin connectors on bikes, cars with age anodize creating electrical nightmares.

 

That black module in pic #2 looks to be a run, turn, brake module. Get it out of the circuit and put the wiring harness back to stock. Any blue 'Scotch Locks' on the wiring harness ? Diss those too !
That grey connector in post #5 pic looks to be the accy. power. With the ignition on check for B+ volts across the pins. If volts are present do they go zero with the ignition turned off? That would be a switched power supply, good to have.

 

I had that problem on my sportster finally tracked it down to the wiring inside the rear fender was broken on the little fixing clips

 

I have a similar proble with my 09 FXDC. In a nutshell my rear signals do not work or flash. My front one's do, only if I disconnect the wiring to the back one's. Additionally when i try the signals they make a buzzing noise as the flashers try to blink.

 

I have a 1999 FLSTC. Got TS issues also, gonna replace Signal Cancellation Mod "Another winter Project". The cancellation mod is located under dash between tanks infront of speedo.