Pulsing lights

[franklin2]

Thanks for this post. I have an '86 F-250 Supercab, 6.9, with some similar issues. Haven't ever noticed pulsing lights, but, then, I seldom, if ever, drive in the dark, either. Don't want to hijack the thread, so Mods feel free to kick this or open new thread.

I just replaced glow plugs, adding pushbutton for pre-heating. He still hates first-start, though. Once I've gotten him running first-time of the day, no problem. But, apparently, he's not a morning person. Lol. I'm not sure coffee into the intake will help, but not opposed to trying, I suppose.

My other issue is the one that drives me a little nuts. He has an after-market cluster installed just below the dash with charging, oil pressure, and temp gauges. Once started, charging gauge needle pegs to left side of the gauge, and only reads correctly after I turn on headlights. I suspect a ground problem, also, but it appears that my wiring behind the dash may have been done by the same guy as OP. In other words, it's a rat's nest. I've had the truck going on six years, and drive it with no electrical problems, other than the aforementioned gauge anamoly.

I'm admittedly not a gearhead, should have spent more time under the hood with my Dad, but any help Will be greatly appreciated.

Thanks. Be well.

On your cold natured engine, you need to get under the hood with a testlight, unplug the wires from the glowplugs, and then clip the alligator clip of the testlight to one of the + posts of one of the batteries, and then touch the sharp tip of the testlight to the tip of each glowplug. If the testlight lights up bright, the glowplug is good. If not, it's bad and needs to be replaced. If you find some bad ones and replace them, that will help your cold starting.

On your under dash gauges, do you have a volt gauge or a ammeter gauge? If you have a ammeter gauge, I would pull all that wiring out and just leave the ammeter guage in there to plug the hole. Or go buy a volt gauge and put it in the hole. You have to be very careful and use very heavy wire for ammeter guage, and the wiring has to be run very carefully, or a fire can be started very easily. So check what type of gauge you have.

 

[IDIBRONCO]

I hope Tony has a voltmeter under the dash. Even the 1G alternators put out enough amps that it's hard to use an ammeter with them. The factory gauge is an ammeter, but that's from the factory an not an owner add on. I also hope that Tony put Motorcraft/beru glow plugs in when he put in the new ones.