Timing Light Power Connector

[RRoller123]

So I got sick of always fenagling around getting the timing light powered. It is a real pain on cars with the battery in the trunk. And putting the clip directly on the Alternator is out of the question. So I rigged up a power connector over on the passenger side, using an inexpensive 2-pin trailer connector, from Advance Auto parts, etc. Tucks away behind the coolant bottle when not in use. The positive side is the insulated half of the connector.

The power comes from a wire tapped into over at the Alternator (a direct wire from the Alternator stud) and runs through the loom over to just above the coolant overflow bottle. The other side grounds there too. to the inside fender wall. Then I cut off the Timing Light clips and soldered on the other half of the 2-pin connector, and also added a great length of shrink wrap to keep all the wires in place and untangled.

Overall, much safer, easy as pie, and works great. (too much free time, I know)

[dinghyguy]

I did almost exactly the same thing except I just unplugged one of the headlight power plugs and used it ('79 has exactly the plug you bought). I didn't want to cut up the timing light so I just put the + in a ziplock bag to ensure it did not short to ground. I guess I either had less time or more likely was too cheap and lazy. But you do have to have the lights on to use it, but no big deal cause the car is running when timing.

nice pictures though

dinghyguy

[RRoller123]

Whatever makes it easier and safer!

[bobplyler]

My timing light works if I attach one lead to the distributor, and the other to ground.
Sounds wierd but it works for me.

EDIT I meant coil.

[RRoller123]

Where on the distributor do you attach it? That is odd. Maybe it is the xenon bulbs that require a 12 VDC battery connection?

[Odoyle]

Attach the red lead to a stud on the alternator, and the black lead to anywhere on the chassis.

[zachmac]

And putting the clip directly on the Alternator is out of the question.

Why is this "out of the question" when you are doing the same thing remotely? Is it just that you were worried about the clip moving and shorting to the alternator casing?

BTW, I also just use the + terminal on the distributor. Looks like you are running an EDIS which of course rules that out but there should be a +12 v feed there as well.

[RRoller123]

Because it leaves a loose wire very close to the moving belt and pulley. Maybe 6" away. Dangerous. You then have to drape the wire/s back up over the engine, across to where you can aim the light. This exposes the wire/s to touching the exhaust, which will burn the insulation, or getting caught in the cams or timing belt. The large alligator type clip could also move on the alternator stud and short out to a ground, like the alternator case, etc. None of which is any good.

Having a power connector for the timing light up by the coolant overflow bottle keeps all the wires out of the engine bay, draped over the fender, as you aim the gun back inside towards the crank pulley. Especially neat if you have the coil packs from the Compu-Tronics up on the sidewall just in front of the coolant bottle.

[spider2081]

I agree connecting a timing light to the alternator output post can be difficult and unsafe. Some of the protective boots that cover the alternator output post have become very stiff over time and can easily be damaged. Others push the timing light clips off the post while engine is running.
The alternator output post is hot all the time so this connection should be properly insulated at all times. I see lots of Spiders at car shows with the protective boot missing. This is not safe. Shorting the output post with a wrench could damage the alternator/regulator and cause an injury.
Adding the trailer connector shown in this post also provides a great connection for a battery tender when the car is not in use.

[wideopenplains]

I'm curious here, as I've just been using a jumper cable from positive on the battery, and clip the other end to my timing light. I make sure it's on an insulated surface so it won't ground, but is there any other danger to doing it this way?

[RRoller123]

I did it that way myself until now, using a light AWG wire, like 14 or 16, with a small alligator clip on the battery (+) terminal. I figured if it shorted, the wire would melt pretty quickly. So your approach is sort of ok, any danger would arise from all the exposed metal on the clips at the other end if it contacted a good ground. I used to cover the connection with the timing light with electrical tape, which is kind of a pita. But an Automotive Jumper Cable, attached to the (+) side of your trunk battery, can carry a LOT of amperage, and there would be quite a fireworks show if that happened. Possibly the clip could weld itself to whatever ground it contacted. I suppose it is even possible that a sudden enormous discharge of that sort could explode a battery, but that is pure conjecture on my part.

The problem with timing lights is that we move them around during use, pick them up, set them down, change their position as we aim them, etc; so wires draped across a running engine can move and are very much inadvisable. That's why I put the connector up near the coolant bottle; none of the three wires are even in the engine compartment now.

[kilrwail]

Great minds etc, etc.

I did something similar years ago, when I permanently terminated three wires under the black box you see here in front of the left end of the radiator. One each for the starter motor, positive battery from the alternator and the tachometer lead from the coil. I use those during tune-ups to advance the engine with the starter using a remote switch; to connect a timing light; and to connect a dwell meter to adjust the points. Every person who saw the engine bay at FFO pointed to the black box and asked what it was

[Odoyle]

I think you guys are overthinking this one, you can clamp the red lead on to any stud on the back of the alternator, not just the stud with the insulated boot. As far as routing the wires away from the rad fan... no big deal, and if you really concerned with alligator clamp coming off, cut the clamp and install the proper size ring terminal and bolt to an alt stud.

[RRoller123]

Great minds etc, etc.

I did something similar years ago, when I permanently terminated three wires under the black box you see here in front of the left end of the radiator. One each for the starter motor, positive battery from the alternator and the tachometer lead from the coil. I use those during tune-ups to advance the engine with the starter using a remote switch; to connect a timing light; and to connect a dwell meter to adjust the points. Every person who saw the engine bay at FFO pointed to the black box and asked what it was

That is a really clever approach! Excellent!

[spider2081]

you can clamp the red lead on to any stud on the back of the alternator

Not sure of all the alternators used by Fiat but the Bosch alternators have one output terminal with battery voltage available. It would have had a boot on it when it left the factory.