Then explain why i can go out to my 980 cranking amp optima, no fuse, and hook a dash light up to it....and nothing will blow. Sorry, that just doesn't make sense to me. You can wire it in that circuit if you feel, throw a 5a fuse into that circuit and you will have no issue. Current flow through a circuit is based off the resistance of the loads and the voltage applied to them. Ohms law,
Here are three lights hooked up to a 980amp 'circuit', however due to the resistance in that circuit, only 21amps goes through it.
I'll be more than willing to demonstrate, I'll gladly run three dash lights off my alternator output wire with the alt fully loaded with accessories (90a alt).
I think I know about Ohm's law...I'm an electrical engineer. Been working on safety sensitive railroad signal systems and traction power systems for 25+ years.
Do you know what a short circuit is? What is the resistance of a short circuit? Let me tell you, it's ZERO ohms. What is the current when flowing thru zero ohms? It's the maximum capacity of the source (theoreticaly it's infinite current). So if a lamp socket shorts out (as i pointed out in my first post), and you wire the dash lamps (which use #18 wire) to the headlamp ckt you are asking for a problem. Tha capacity of #18 wire is around 5 amps. The headlamp ckt's is set up to supply at least 30 amps. If thats not a potential problem to you, then you dont know any better. The wire will become the fuse and melt, thats what a fuse does, it melts when it blows. I'd like to see your little experiment with a battery and #18 wire and a short ckt....you would not be smiling when it was over if you held that #18 wire in your hand.
When people modify these car's electrical circuits and dont know what they are doing, that's what causes dash fires and other problems. The post i responded to did not say an inline fuse would be utilized. I'm just trying to help someone from doing something to their car that might set up a potential disaster.
As said by someone else in this thread, I've seen plenty of hack jobs on electrical systems on these cars thru the years.
By the way, if you are going to modify the inst lamp ckt feed, better to run it off of the tail lamp ckt or parking lite ckt with a 3 amp fuse inline or tap it off of the fused side of the ckt. The headlamp ckt is hot only when the headlites are on....if you have just the parking lites on, you will have no instrument lamps. The best solution is to replace the instrument dimmer and repair the ckt if there are any other problems, 2nd best is to jump it out. Fix things the right way, anything else is just a bandaid.