Trying to find the headlight ground splice on TC-35D

[HotBlack Deisato]

I've got 3 of the 4 headlights out on my 35D, and they all went out at once, so I suspect the ground splice. I just can't find the &(*@#)&-ing thing. Anyone know where it is? The wires to/from the headlamps are sleeved, and I don't want to cut it open just to go looking...

Thanks in advance!

Steve

 

[jinman]

Steve, welcome to TBN. Have you tried using a jumper to provide ground to each light to prove that ground is the problem? I would not cut anything until I knew that ground was bad. You could also "ring it out" with an ohmeter and check for 12 vdc with a voltmeter or test light. You may have done all these things. Anyhow, if one light is working, it's my guess that ground is not your problem. Perhaps your alternator is putting out too much voltage and burning out the lamps. Have you tested the lamps to make sure they are good/bad?

I don't want to 2nd guess your problems, but my electrical/electronic background really gets me going when I hear a problem like this. My schematic says the ground is a black wire from each light, and it goes to connector C6, pin 2. There is a tiepoint shown, but no indication of where it is located. My guess is that it would be close to the lights or there would be no purpose in having the tiepoint. If you have to cut, I'd feel for a bulge in the wire bundle near to the light end. Pin 2 connects to ground at the starter mounting bolt. Sorry I can't be more help.

EDIT: Just checked my Repair Manual. It's not much more help than the schematic in the Operator's Manual. The black ground wires coming from each light are 16 gage wires and after the splice it is one 14 gage wire, but you may already know that. Sorry if I'm just repeating the obvious.

 

[HotBlack Deisato]

Hi Jim,

Thanks for the welcome. I've been here (and posted) a lot under a different name - but I lost the account info and the e-mail attached to it no longer works!

Anyway, it was the ground splice (yes - I took the harness off and rang it out first), and it was located inside the spi-wrap that they put on the harness. The connector for the harness, in case anyone needs to find it, is behind the power steering fluid cannister. Anyway, snipped back some of the wrapping, fixed the splice, and then put if back with some heat-shrink tubing. All good now.

Now I just have to replace my leaking oil cooler (which I found when I opened the hood to diagnose the headlight problem).

 

[jinman]

Steve, the more I thought about the problem as you described it, the more I realized you knew what you were doing or you would not have described it as you did. It seems I was right. Glad you found the problem and thanks for letting us share in your troubleshooting/repair process. I'll try to file this away in my memory bank for future reference. It would be nice if NH marked the outside of harness wrap for the location of splices or gave some indication of how long a wire is by the wire number on the schematic. Perhaps also, these kinds of problems are so few that it would not make economic sense for them to do that.