Turn Signal Relay

[bt7tricarb]

Okay, I think I diagnosed this one correctly, but tell me if I missed something...

Last night I went out for a spin and since it was dark, I noticed my turn signal indicator was not glowing. I checked all the signals and they were working, so I assumed that the bulb under the dash was bad, so I pulled it today and ordered five from Moss.

The more I looked at the bulb, though, the more it looked like the filament was in tact. Now my eyes ain't quite what they used to be so I even looked under a magnifying glass and then even tested it with an ohms meter. After seeing no resistance, I did the ultimate test and pulled the bulb from the combo gauge and replaced it with the bulb in question. Touching it back to ground, it began to glow. So I put the bulb from the combo gauge, that I had also verified as working prior to pulling it, into the turn signal indicator, activated the switch and... nothing.

So then I switched the meter from Ohm to Volt (DC) and stuck the leads on the bulb receptacle and ground (steering column mount), activated the turn signal switch, and... nothing.

So then went under the bonnet, located the turn signal relay, activated the turn signal (left), located the L terminal on the relay and put the volt meter leads to it and ground. The meter kept reading 0, 10, 0, 10, etc. So then I located the lead that went to the indicator light on the dash, put my leads to it and ground and... nothing.

I also checked the fuse box (all wires still connected) and the fuse (still good). So, it's the turn signal relay, right? I'll call Moss in the morning and see if it can still be added to my current shipment due to go out in the morning. Anything else I should consider immediately?

 

[Ed_K]

Recap... All 4 signals working, just the dash indicator bulb(s) not working ?
Sounds like a bad flasher ( the little round thing, not the big relay on the inside of the fender on a BJ8 ).

 

[TimK]

Not necessarily; the flasher unit powers the light on the dash, not the relay. I'd check the flasher to see if it is putting out current to the bulb. Check the P not the L or the B. If you don't have P L & B connections, look for the light green wire that goes to the light from the flasher unit. Flashers are a lot cheaper than replacing the relay.

Ed K & I posted nearly at the same time... we agree, check the flasher

 

[GregW]

Hi Devin,
I"m thinking you have a loose connection on the light green/ purple wire under the dash. At the flasher can that Ed mentioned, check for voltage between the light green/ purple terminal and ground with the turn signal on. It should do the 10-0-10 thing like you've already seen. If not, it probably is bad. Under the dash the light green/purple wire branches at a butt connector, I'll bet this is where your problem lies.

 

[bt7tricarb]

Turn signal relay = flasher ("that little round thing" as described by Ed K.)

That's what I'm talking about. If I'm not mistaken, the original shop manual calls it a turn signal relay (they call the large fender mounted unit a Flasher Relay), so that's the term I was using. Sounds like we're all pretty much in agreement.

I've already checked for loose connections (see above, but I think the wire is solid light green, not with the purple stripe... the one with the purple came off the fuse box to the L relay - left signal - if I remember correctly). And, again, everything except the flash indicator on the dash is working and I was getting a voltage reading from the lucar terminals on both terminals that went to the signal lights, but not from the one that went to the dash light.

I ordered the part first thing this morning from Moss (along with something else I wanted - one of those really cool temperature "guns" with a laser pointer!), so I should be back in business tomorrow.

I'll scream for help if it doesn't work.

Edited to add:

Oh - and thanks, guys!!!

 

[GregW]

the one with the purple came off the <span style="font-weight: bold">fuse box</span>

Well that has been changed at some point. There should only be one color of green wires going to the fuse block and they shouldn't have tracers.

And, again, everything except the flash indicator on the dash is working

So if the flasher is working, why are you replacing it?

and I was getting a voltage reading from the lucar terminals on <span style="font-weight: bold">both</span> terminals that went to the signal lights, but not from the <span style="font-weight: bold">one</span> that went to the dash light.

Does your flasher have more than three terminals?

 

[bt7tricarb]

the one with the purple came off the <span style="font-weight: bold">fuse box</span>

Well that has been changed at some point. There should only be one color of green wires going to the fuse block and they shouldn't have tracers.

<span style="color: #3333FF">I'll have to verify, but I thought the wires for the signals were coming out of the fuse box... Again, not sure as my car is in my garage at home. I know the wiring is all correct. It was done by the restoration shop, not me, and they've done hundreds of these. It's also been viewed by enough people that know these cars that someone would have said something to me... No worries there. The wiring is right.</span>

And, again, everything except the flash indicator on the dash is working

So if the flasher is working, why are you replacing it?

<span style="color: #3333FF">The signals ARE working, but the flasher indicator light on the dash is NOT working. As the bulb is good and the tests seem to indicate the the flasher is the cause, I'm repalcing it... As I've said, two work (the ones going to the signals), one does not (the one going to the dash indicator light). I want them ALL to work. That's why I'm replacing it.</span>

and I was getting a voltage reading from the lucar terminals on <span style="font-weight: bold">both</span> terminals that went to the signal lights, but not from the <span style="font-weight: bold">one</span> that went to the dash light.

Does your flasher have more than three terminals?

<span style="color: #3333FF">Hmmmmm.... Two terminals that go to the lights. One that goes to the dash... Yep, it has three.</span>

Edited to add:

I just re-read this and want to clarify... If you detect sarcasm, it's self-directed and NOT directed towards you. It's me saying to myself that I don't know the answers. To reiterate my original post - I think that I've got it figured out (I'll know for sure when the new flasher unit arrives tomorrow), but wanted to see if there was something obvious that I may have overlooked.

I appreciate everyone's help.

 

[TimK]

Devin, I'll bet you have it figured out. Please let us know the outcome.

 

[GregW]

So then went under the bonnet, located the turn signal relay, activated the turn signal (left), located the L terminal on the relay and put the volt meter leads to it and ground. The meter kept reading 0, 10, 0, 10, etc. So then <span style="font-weight: bold">I located the lead that went to the indicator light on the dash, put my leads to it and ground and... nothing.</span>

Looks like I missed that paragraph first time around. So yes, if you checked the "P" terminal that the light green /purple wire attaches to and there was no voltage, bad flasher.

Oh thanks for explaining about the sarcasm, I hadn't noticed though. :laugh:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Hmmmmm.... Two terminals that go to the lights. One that goes to the dash... Yep, it has three.[/QUOTE]
The reason I asked was on a three connector flasher, one lead goes to the relay (all turn lights on body), one goes to the dash. The third wire is hot input from the fuse box. Of the three mentioned, none was the power line.

 

[bt7tricarb]

The reason I asked was on a three connector flasher, one lead goes to the relay (all turn lights on body), one goes to the dash. The third wire is hot input from the fuse box. Of the three mentioned, none was the power line.

Hey... that makes sense! Thanks, and I'll let everyone know. If it's not it, I'll be back begging for help!!

 

[bt7tricarb]

First of all, thanks to all who helped! It was the relay (that little round thing). All lights, including the dash light, are working again.

- Devin

 

[TimK]

Glad to hear you got it fixed, but to avoid confusing the rest of us, please call the little round thing the flasher.