Ok, this is more for those who have a 66 since the Custom Cab sweep dash will have the amp gauge with the dedicated harness for it.

Now I have seen previous schematics here for connecting it but it seems the schematic leaves out one important connection. In a 65 you have the engine gauge harness coming out of the firewall which makes its way to the starter relay. On the battery side you connect the black with yellow tracer wire with the red/blue tracer going to "S" and the black to "B". The alternator harness makes its way across the radiator support with the a black wire and yellow wire attaching to the battery side of the starter relay.

Alright with an amp gauge you have that harness supplying a black/yellow heavy gauge wire to a junction block on the inner apron. The heavy gauge black wire goes to the battery side of the starter relay. The black and yellow wires of the alternator harness now go to the junction block with the heavy gauge black/yellow. All diagrams show this however they do not show where the engine harness with the black/yellow wire goes. Does it stay at the battery side of the starter relay or does it to move over to the junction? Your truck definitely doesn't start unless it is somewhere. I just want to be sure which position it should be before I turn the ignition to start and cause something I might not like...?

 

Mike, not sure if any help? Took me couple years to connect the alt guage, even with advise from number of member, I just could not figure out the circuit. Some time later a member emailed a diag., at least to me, it made since. Did not have a harness so purchased the wire. Did not want excess amp going to instrument cluster without circuit being fused. Happened to have a 50 amp fuse block that I found dangling on the end of a heavy gage wire in the back of 66 Ford pickup and have no idea what it's used for. Posting pic of diag. member emailed, may be of some help. 2nd pic is of the fuse block I mounted on passenger side inner fender. Not an authority on auto electrical circuits so not sure if the way I ran the alt. gauge is correct, or simular to Wiring Manual. Seen too many burnt out classic Ford pickups in salvage yard so important you feel comfortable in how you run the alt circuit. Finally got around to installing the alt gauge about 3 yrs. ago it works great and never had any problems.

http://i300.photobucket.com/albums/n...os/Scan1-1.jpg

http://i300.photobucket.com/albums/n...IMG_0002-4.jpg

 

Mike, On my 66 it had a alt.light, It never came on. I had voltage all the time to both sides of the wires to the alt.light. I look at the elec. manual, and it was for a amp.gauge. not a light. I think you tryed to help me out. I didn't want to hook something up and watch everything go up in smoke...The battery was charging ok, So I went to autozone bought a amp.gauge and hooked it up and it works fine. When I fig. it out, I'll hook it up next time around.I Know it doesn't help you, but I as yet found a good wiring schematic for my truck.


Jeff

 

Found changing the connections for the 'alt' guage did not influence the idiot light, both work fine.

With power to both leads to the idiot light, could it have been bulb or socket? Had a heck of a time locating an electrical gremlin in the instrument cluster and found the bulb socket was defective. As noted, not an authority on auto electrical, fortunately it has been some time since had to get under the dash; having said that, don't recall if the idiot light circuit had the 8-10 gage wire and/or junction blocks as does the 'alt' gauge circuit. Wonder if the idiot light circuit could be compared to the voltmeter guage wiring. Although, Jeff, you mentioned replaced the idiot light with an alt gauge and it's working fine. Wish I could understand this electical struff.

 

Dave, The way I understood it that both wires to the amp.light had power,and that made the light not work. When the engine was started the alt. charged and a relay, I think in the voltage reg.,turns off the power to one side of the wire and the light go's off. As to the amp.gauge, I mounted it under the dash. It just hooked into the power (made sure the power was off to the gauge when the key was turned off) and made sure it had a good ground. Cost about 23.00.


Jeff

 

Ok, Dave, your second link was better. I already had the first diagram and it is missing the wire I am talking about. I want to see the wires at the starter relay and the block. The second photo shows the block with the alternator harness black wire and the amp gauge harness black/yellow wire. However, the yellow wire that travels with the alternator black wire I see is missing.

Now at the starter relay I can see 3 wires unlike the drawings 2 wires only. If you look behind one can see the black/yellow wire of the engine harness behind the red battery cable. This was the wire I was referring to and now see where it is.

Of course you now confused things as you have a white wire sharing the bundle with the large black wire at the block. Exactly where does that white wire end up going to? Two, where did you get those blue heater hoses?

 

Sorry, the red and white are the wire's for the Duraspark ll electronic ign. Appears you have it figured out, just to clarify, mounted the fuse block on inner fender then removed the blk/yellow wire that was originally connected to the batt. side of start relay and moved it to 1 side of the fuse, or junction block. I then ran another wire from the other side of the fuse, or junction block, and ran it to the alt gauge. I then ran a separate wire from the other side of the alt guage to the start relay which is the heavy gage wire seen in pic. Exactly as it appears in diag. Again, may be unorthodox but it works for me. For lack of anything else to do, posting pic of alt. harness. Purchased the hose from local auto parts store, Winchester Auto Parts, they are located in Bay area, understand they do ship but the hose is expensive enough as it is.


url]http://i300.photobucket.com/albums/nn25/goatfarmer_photos/MrMustangincwireharness.jpg[/url]

Jeff, thanks for the info, wow $23, definately have to keep it in mind in event mine starts acting up.

 

Sorry, the red and white are the wire's for the Duraspark ll electronic ign. Appears you have it figured out, just to clarify, mounted the fuse block on inner fender then removed the blk/yellow wire that was originally connected to the batt. side of start relay and moved it to 1 side of the fuse, or junction block. I then ran another wire from the other side of the fuse, or junction block, and ran it to the alt gauge. I then ran a separate wire from the other side of the alt guage to the start relay which is the heavy gage wire seen in pic. Exactly as it appears in diag. Again, may be unorthodox but it works for me. For lack of anything else to do, posting pic of alt. harness. Purchased the hose from local auto parts store, Winchester Auto Parts, they are located in Bay area, understand they do ship but the hose is expensive enough as it is.


http://i300.photobucket.com/albums/n...ireharness.jpg

Jeff, thanks for the info, wow $23, definately have to keep it in mind in event mine starts acting up.

 

Wait a second. That black/yellow wire is still connected to the battery side of the starter relay in that photo link

I assume you are referring to the "amp" gauge when you say alt gauge?


In this picture you can see the heavier black wire joined with the smaller yellow wire. That is always at the battery side of the starter relay except when amp gauge is used. I do not see that in your first pic of your set up. So where did you put it as there are really only two places and I don't see it on either one?

Last, tell me when you have the truck off and blow the horn does your amp gauge register a discharge?

 

If I were to peel the tape off of the wire going to the fuse block it will be solid blk and solid yellow joined at the connector.



The black wire currently connected to the batt. side of start relay is going back to the 'ALT' gauge. On my 65 the lettering on the gauge states 'ALT', assume stands for alternator; whereas, yours may say 'AMP', in either case I would assume they are one in the same.

 

I'm resurrecting this old thread because you guys have done this and I would like your opinion on this wiring before I start soldering ends on it. I know that Chinese circuit breaker might not be the thing to use but it was free. This is wired up exactly like it was in the f250 I removed it from with the exception of adding the breaker in the Black wire. All the Blk/Yel wires are together with only the Black one on the start relay. I know the one going from the relay to the breaker has a red stripe but that was the only #8 wire I had.

 

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