troubleshooting headlight relay?
 

I installed the headlight relay I bought from Pelican on my '81 SC, and now I have no headlights -- low or high beam. Headlights worked before installation.

Where do I start to trouble shoot? I will re-check my electrical connections, since that seems the most likely culprit.

Does anyone have "Troubleshooting headlight relays for dummies"-type advice? I have a multi-meter, but not much electrical troubleshooting experience.

thanks
John
1981 911sc Targa

Post a photo of what you did at the fuse panel.

Here’s the fuse panel and relay installed

With photohttp://forums.pelicanparts.com/uploa...1585875509.jpg

Maybe list what the instructions said to do, and how you did it. Really hard to see the wire colors and where they go in the photo.
All changes were made to the wires going into the top of the fuses on 5/6 and 7/8 correct?
Power to the relays to a constant power supply?
Good solid ground?

So,

I keep this 'ammended version' in my car to show how the wiring should end up - see image below.

I assume you removed white wire (fuse7) and the yellow (fuse6) for the right & left headlights and had to connect them to the same coloured wires from the relay set.
(in my drawing it says cut, but it's actually remove them from the top of the fuse and cut the crimped connector off)

The Yellow gets replaced by Green on top of fuse6, white by blue wire on top of fuse7.

The red (thick) wire from the relay set goes DIRECTLY to the + pole on the battery, the brown one needs to be connected to the G106 ground point witch is in the front of the car near the battery (I had to get my large battery out to get there).

In the end, check if all fuses are seated properly and have not moved.

http://forums.pelicanparts.com/uploa...1585894246.jpg


If you want to check it with the multimeter (on Volts) :
pin 30 (red wire) of both relays should always have +12V - be careful - UNFUSED, ALWAYS HOT
Pins 87 (blue, green wires) should be 12V with the lights switched on, you can also measure this at the top of the fuse.
Bottom of the fuse should also have 12V with the lights switched on.

If you remove the relay and put the lights on, you should see 12V over terminal 85 (yellow or white wire) and 86 (brown) of each socket.

Meter on ohms/continuity :
the brown wire, pins 86 of each relay holder should have continuity to ground (measure at any ground point)
Pins85 (yellow & white wire) should have NO continuity to ground when the lights are switched off

Check your butt splices. (I hate those plastic crappy things) likely bad....
Check for power on the red wires from the battery (is there an in line fuse to check? I hope so)
And do all of the stuff listed in the post above...

You may have a look at this webpage translated from french:

https://translate.googleusercontent.com/translate_c?depth=1&hl=fr&nv=1&rurl=translate.goog le.fr&sl=fr&sp=nmt4&tl=en&u=https://www.type911.org/blog/%3Fidblog%3D11001&usg=ALkJrhheNKy1MSNVQxDL1ej5PJHT SXdnxQ

I new I had a better version somewhere, here it is.http://forums.pelicanparts.com/uploa...1585926088.jpg

“The brown one needs to be connected to the G106 ground point witch is in the front of the car near the battery (I had to get my large battery out to get there).”

I connected the ground to the ground point behind the fuse panel, I will check for continuity and see if that may be the problem. I followed all other instructions exactly.

I suspect it may be my splices .

Thanks for this comment. Helped me understand my Foglight troubleshooting on another thread. I always though that pin 85 is ground and power should come to pin 86 when the foglight switch is pulled. Mine works as per your direction above, although it makes no sense to me at the moment. I need to sit down and try and understand the logic.