Hooking Up Headlights and Backlight

[8N_John]

I am planning on hooking up headlights (standard replacement) and a backlight (50watt/4amp) to my 8N this weekend (see pic of headlight and backlight). Have some questions on installation.

How do I hook to my 12V battery? Each headlight has one wire coming out of it and the backlight has 2 wires (see pics). Do I use both wires on the backlight?? I believe the positive battery cable has a small wire coming out of it near the terminal connection- do I hook into this?

What type (amp) toggle switch should I buy and how do I connect (I"d like all lights to be connected to one switch). Where is the best place to put the toggle switch?

Is there a recommended place to hook up the backlight where it"s least likely to get damaged?

Any other tricks in hooking up the lights to a 12V system?...I"m not good with wiring so any tips will help.

 

[stevenf]

John I'm no electrician but you probably should either open up the light with 2 wires or use a testor on it because I'll lay you odds that one of those leads is riveted or connected to ground inside that light. Just touch one lead of the meter to a lead and the other to the mount if you get a continuity reading thats your ground (take the bulb out first before checking). Another easy way if no meter is take a good d flashlight battery into a dark closet and touch one end of the light lead to the bottom and the other to the top if you see a faint glow you'll know positively that the wires coming out are 1 positive and 1 negative. You probably should still crack that light open though to see which is which the light stands a good chance of being grounded to the case and to one wire.
I'm sure with all the electrical engineers on this site someone will chime in and give you a more technical, correct way to hook it up and check it but for sure don't try it until your certain because if your circuit is fused heavy enough you'll blow a big hole in your brand new light or worse start a little electrical campfire on your tractor.
Steve

 

[DmansPadge]

The light with one wire should just need a battery source and will ground itself to the tractor (ofcourse it needs to be mounted to a metal surface. The two wire light will probably need a battery source and ground (unless maybe it's a dual bulb light?). If you wire direct to the battery make sure you get an inline fuse and put it in between your battery and switch. I would imagine just about any toggle switch at the local parts store will get the job done. You may also be able to find a power source at the fuse block and you could simply tap into the dead side of the fuse (the side that doesn't have constant power).

Thats a quick rundown. I'm sure others will post as well, but if not and you need more detailed help, send me a PM.

 

[JD3130]

On the 8N, the light switchs are mounted up under the dash out of the weather on the left side. Brackets may be missing. You can get the push/pull switchs from NAPA with the fuses build in. The wiring ran along the transaxle, most have a little hole in rim of trans that the wire goes through (suggest you put a connector there, in case you ever have to split the tractor). along the axle up the outside the fender inside the brace out the hole to the lights. Trailer wiring works nice for this. Some 8Ns had a light that was a worklight/taillight.(reddot) when you pulled the switch out one position the red lite, pull it again the second light came on. Needed two wires for that light.
JD

 

[varmint]

The wiring advice is right on, but also be aware that having all your lights on at one time can run down the battery- on my B8200, the little altenator can't crank out enough amps to run the original headlights and the two extra work lights at the same time- well, they can all be one at once, but a glance at my voltmeter tells me that it isn't a good thing, long term. Too bad, 'cause we need all the light we can get sometimes.

 

[DirtHauler]

You may want to add a couple of relays to that light system, use "in-line" fuses on your main hot leads if no room on the main fuse block. If the back light has a plastic housing then one lead is a ground and if the bulb is a "bayonet" type (not push 'n' twist) base then either wire can be grounded. /forums/images/graemlins/cool.gif

 

[Soundguy]

Don't trust your 50 year old rusty sheetmetal as a ground for the 1 wire lamps.. run a seperate ground and terminate it with a ring terminal under the lamp base mounts.

Get a switch rated for the total load.. fuse it.. and have fun.

Soundguy

 

[JD3130]

John,
Varmint, may have a point about the load, but I notice you have a 12v system, so I guessing you have a Alt and not a gen. right? If you don't plan on restoring it to show. the best investment you can make is the single wire, continuous charging Delco Alternators from NAPA, PEPBOYS, or your Ford Tractor dealer. Here they are $65.00-70.00 with core. Does away with all that troublesome problems 8N have. Dealer will install it for about 75.00, but you can do it. Making the new Alt bracket is the hardest thing you have to do. I've had them on both mine for over ten years with a no problems.
JD

 

[Soundguy]

</font><font color="blue" class="small">( the best investment you can make is the single wire, continuous charging Delco Alternators )</font>

I disagree. While a single wire alt is deceptively 'easy' to electrically install.. it introduces other issues. For instance.. the delco 10-si 1 wire job in it's most common vr configuration makes you throttle up to about 1800 rpm to self excite. Optionally you can change out the vr for a lower 900 rpm self excite.. this bumps the money up over other possibilities. Also.. pulley change outs can help the rpm issue.

The 'better' option IMHO is a 3 wire job. Just a few buck more.. however most autozones.. etc.. carry the 3 wire 10-si in the 30-40 dollar range. That and a uni-bracket kit a toggle switch and a bit of bracket ingenuity and you are good to go.

On the 3 wire jobs, P1 goes to excite.. and can be run to a toggle switch with a power feed. Can be momentary or not. Could even use a correctly oriented and sized diode for 'auto-magic' starts and field isolation. p2 is voltage sense. on an automobile you would install it hooked to the battery terminal to make up for lost voltage inthe long wire harness. On a tractor with about 3' of wire harness it is quite acceptable to drop the ps right down to the charge stud. These puppies charge at 14.4 to 14.7 anyway. Start the tractor and at just about any speed above 450 rpm, and you energize p1 and you are good to go. Most of these variants are 30+ amps.

</font><font color="blue" class="small">( Does away with all that troublesome problems 8N have )</font>

Ford N charging systems don't have problems by design. Non maintenance by owners, and hack and slash refit jobs by well meaning shade tree mechanics cause most of the wireing/charging problems I've seen on any flavor of tractor.

I have restored 4 fords.. a 2n with a delco 3 wire alt.. a 8n with stock 6v a-circuit genny.. a NAA with 3 wire alt, and a 660 with stock 6v b-circuit genny.

The 6v jobs work fine. The 8n genny was rebrushed and has a new vr.. the 660 is stock anbd has a stock 50 year old vr. Both charge past 20a fine if you full field them. Keeping electrical connections clean bright and tight is the key.. not repowering. Also.. most repower jobs I see are to bandaid a weak starter.. or tired engine lacking sufficient compression to start on a 'slow' 6v starter. Throw in a 12v charger, and that old tired 6v starter and engine whizz over and start. deffinately an engine bandaid.. not a charging system fault.

About the only reason I see to repower to 12v is if you need more lamps than the genny can pull, or need 12v implement applications. In any event.. I'd rather have a 12v genny re-wire than an alternator.. Gennies are much more forgiving of bad wireing and bad maintenance. 1 second on flopped polarity can waste an alternator. whereas a geny will simply smoke some wireing.. possible weld the contacts in the cutout.. etc. Besides.. gennies are polarity agile...that's a tall order for an alternator. At 25a capacity on a rebuilt 12v genny.. that should cover most casual tractor users needs. If ya need more.. then that is a 'good' reason to hit an alternator..

Soundguy

 

[JD3130]

I still stand by what I say. Maybe it has to do the your warm weather. I too restore tractors. I have 4 tractors, a backhoe, two welders, two forklifts, and cement mixer all using those alt's and haven't had any problems. I have intalled them in a number of customers tractors and only had one come back, and that was for a bad battery (new battery, had a weak cell). I only put a 6v in one of my 8Ns and the was one I rebuild for show. I put a whole new wire harness in it, which was $70.00, then the voltage reg, rebuit gen, etc. it ran over 250. and that was years ago. Cheaper to just go to the Alt, if you do it yourself.
One of my forklifts must have had 400 ft of wire in it's electrical system. If the temp dropped below 40 or if it rained it wouldn't start. took all that old wire out replaced it with the required alt. Hasn't failed to start in 3 yrs.
So to each his own!
JD