BY passing charging gauge 70 challenger

[wantonebadebody]

Is it wise to by pass the charging gauge and if so
can some maybe explain:
I understand the hot wire goes from the relay on drivers fender to the gauge if by passed can you run a wire from the relay straight to the Alternator?
Instead of going threw the firewall into the car? or does the headlight switch meet the relay under the dash?
Can i run the headlight switch straight to the relay? if so what do i do with the black wire?
thanks in advance

 

[Chryco Psycho]

You can simply run a 10 ga wire from the alt to the start terminal on the relay , this will bypass the bulkhead plugs & the ammeter .
I run relay for the low & high beams under hood this will take power from the start relay terminal directly to the headlights & uses the headlight switch to shunt the relays which is minimal power .

 

[wantonebadebody]

You can simply run a 10 ga wire from the alt to the start terminal on the relay , this will bypass the bulkhead plugs & the ammeter .
I run relay for the low & high beams under hood this will take power from the start relay terminal directly to the headlights & uses the headlight switch to shunt the relays which is minimal power .

ok, so i disconnect the black wire at alternator run straight to relay and disconnect red from relay that heads in firewall.
and then i run my headlights separate with an added relay to the headlights, where do i catch the head light lead? is that under the dash originally?
thanks for the info.

 

[Chryco Psycho]

No leave the factory feed at the alt & add the second one to the relay the electricity will take the shortest path , I would also add a fusable link between the alt & relay .

 

[wantonebadebody]

No leave the factory feed at the alt & add the second one to the relay the electricity will take the shortest path , I would also add a fusable link between the alt & relay .

sry, do you leave the connections on the dash gauge hooked up too?
first time by passing want to get it correct.

 

[Challenger RTA]

Follow the dots.understand how it's wired first. Blue charge circuit,yellow battery supply,red ACC circuit. Headlight sw is feed from splice one under dash.

One word explains the wiring and connections. Inadequate! Read Description and follow the dots. The wiring is not heavy enough and the connection were not designed to carry that much amperage 1:RED wire 16 Battery power yellow dot to splice one feeds fuse block, 2:charge wire 18 black wire blue dots to splice one through amp meter to red wire blue dot 16 to battery, 3:ACC feed from splice 1 Red wire Q3_12R yellow dot to steering column. Black wire 12BK red dot to ACC side of fuse box.ch load. The round back alt has an output of 37 to 45 amps max and the wiring is designed for that.
When everything is in good shape.

 

[bc3j]

FWIW I like using the ammeter and used Chrysler’s fleet bypass. I ran a 10 ga wire from alternator through the clutch plug (auto trans) to the ammeter, then a 10 ga wire from ammeter back through the clutch plug to the starter relay with a flusible link bypassing the bulkhead connector. Also use headlight relays powered at the Bat terminal on the alternator.

 

[wantonebadebody]

jeez im confused!!!
got this car running did a lot of mechanical work but I am stumped on the wiring I just can't wrap my head around it.
In about 10 seconds I'm gonna put this car up for sale which I already put it on craigslist but I'm going to post it in the for sale session any minute.
My relay is heating up someone bypassed the fuse panel with the hot wire from the relay to the amp meter red side the black side go straight to the alternator now I found a bunch of wires soldered together I think that's the factory connection I believe the headlight switch wire went to that not sure or can I run it to the hot on the amp meter?
Otherwise if anybody wants a matching numbers 383 pistol grip four-speed 70 challenger R/T that does move under its own power and has wiring issues let me know 25K takes it here's a picture

 

[Avalanche]

What exactly is wrong with the wiring? What problems are you having?
If you want to take the load off the ammeter, just run a wire from alt to relay, like cryco said. Nothing else changes and no other wiring needs to be done. Ammeter will no longer read properly, but everything will work fine.

 

[wantonebadebody]

What exactly is wrong with the wiring? What problems are you having?
If you want to take the load off the ammeter, just run a wire from alt to relay, like cryco said. Nothing else changes and no other wiring needs to be done. Ammeter will no longer read properly, but everything will work fine.

Well I did that with a 10 gauge wire and I'm about to try it again the relay is heating up also someone rewired the amp made it through the firewall outside the fuse box there's a wire going from the alternator to the black on the amp meter and then there's the red wire goes straight to the relay then there is that factory soldered mess under there and I'm not sure where to put the headlight switch everybody says to run that switch separate but why can't I just put that right on the hot side of the amp meter?

 

[wantonebadebody]

So that's the black and the red from the amp meter and the hot lead from the headlight switch beyond that is the main hot that goes to the accessory on the fuse box and also goes to the ignition switch if that makes any sense I put a nut and bolt on there because I don't have my gauges in right now

 

[MoparCarGuy]

No leave the factory feed at the alt & add the second one to the relay the electricity will take the shortest path , I would also add a fusable link between the alt & relay .

I agree with Chryco Psycho. Essentially, you are adding a second path from the Alternator stud to the starter relay. This becomes the path of least resistance for current flow. Current will also flow through your ammeter but with far less amperage. The extra fusible link is precautionary and highly advisable.

What exactly is wrong with the wiring? What problems are you having?
If you want to take the load off the ammeter, just run a wire from alt to relay, like cryco said. Nothing else changes and no other wiring needs to be done. Ammeter will no longer read properly, but everything will work fine.

I am with Avalanche. What problems are you trying to cure? Our old E-Bodies typically suffer from corrosion at the bulkhead connector which causes all manner of intermittent problems. Tell us what your symptoms are.

 

[wantonebadebody]

I agree with Chryco Psycho. Essentially, you are adding a second path from the Alternator stud to the starter relay. This becomes the path of least resistance for current flow. Current will also flow through your ammeter but with far less amperage. The extra fusible link is precautionary and highly advisable.

I am with Avalanche. What problems are you trying to cure? Our old E-Bodies typically suffer from corrosion at the bulkhead connector which causes all manner of intermittent problems. Tell us what your symptoms are.

Hey guys I appreciate any help and I do take it seriously someone ran the hot wire outside the fuse box I mentioned it before so it runs through the firewall with a grommet along with the wire from the alternator both of those must've burnt before someone used to way long of a wire I shortened it it seems a lot better and I did do the bypass from the alternator to the positive cable I didn't do it to the relay because I feel it's the same thing maybe not you guys tell me. The relay was getting warm now it's not I put a bigger wire from The relay to the battery and that's not getting hot no more but the alternator wire is still getting warm I'm pretty good now.
I'm gonna get a bigger wire to run to the alternator that's just a temporary to see if it worked

 

[72RoadRunnerGTX]

Wires running straight to the ammeter around the fuse box/bulkhead connector? You are describing a bulkhead charging system by-pass, by far the weakest link in the original design was routing the charging current through un-sealed, under current rated, Packard terminals. As mentioned, also referred to the fleet by-pass as the factory did this same by-pass on their fleet production (Taxis & Police) with larger alternators. Nothing wrong with this by-pass, do it on all my builds.

If the ammeter and insulators are in good shape and with proper connections, with the bulkhead bypass in place, no need for the engine compartment charge by-pass being suggested here. Especially running stock sized alternator and loads.

The headlamp switch is feed from two deferent places, B1 (headlamps) is spliced to Splice 1 as is the black lead to the ammeter, as are all other factory loads. B2 is fused at the fuse box and powers the running lights and dash illumination.

If you are wanting to reduce the load at the headlamp switch add the head light relays suggested above. However, connect the power feed to the headlight relays to the alternator stud, not the starter relay as pictured if running the ammeter correctly wired. No added loads at the battery/starter relay if running an ammeter. All loads need to be on the alternator side of the ammeter.

What relay is getting hot? Starter relay? What exactly is the issue you are trying to address

 

[wantonebadebody]

Wires running straight to the ammeter around the fuse box/bulkhead connector? You are describing a bulkhead charging system by-pass, by far the weakest link in the original design was routing the charging current through un-sealed, under current rated, Packard terminals. As mentioned, also referred to the fleet by-pass as the factory did this same by-pass on their fleet production (Taxis & Police) with larger alternators. Nothing wrong with this by-pass, do it on all my builds.

If the ammeter and insulators are in good shape and with proper connections, with the bulkhead bypass in place, no need for the engine compartment charge by-pass being suggested here. Especially running stock sized alternator and loads.

The headlamp switch is feed from two deferent places, B1 (headlamps) is spliced to Splice 1 as is the black lead to the ammeter, as are all other factory loads. B2 is fused at the fuse box and powers the running lights and dash illumination.

If you are wanting to reduce the load at the headlamp switch add the head light relays suggested above. However, connect the power feed to the headlight relays to the alternator stud, not the starter relay as pictured if running the ammeter correctly wired. No added loads at the battery/starter relay if running an ammeter. All loads need to be on the alternator side of the ammeter.

What relay is getting hot? Starter relay? What exactly is the issue you are trying to address

Ok ,so running the wire from the red pos side to the relay is wrong to run it from the Alt stud? 1) please confirm this is ok
I noticed the battery pos & starter relay was getting warm when i had the dash gauges out and put the ammeter wires together for test and run purposes to move the car around.
I thought that is how to by-pass the gauge. put red & black together "both hots"
Since putting the gauges & ammeter back in, they seem not to be getting warm now.
I did run the headlight switch Wire to the red side of the ammeter. your saying no good? to run it to the black Alt "load side"? I will try to explain. here we go!

When i bought the car the by-pass outside the fuse box was already done.
They had a Red pos wire running from the starter relay straight to the red side of the ammeter gauge and is still like this. please confirm this is ok?
A black wire comes from ALT stud "load side" to that soldered block in the Harness above the steering column and the black side of ammeter is this a factory soldered taped connection?
It also looks like it runs and connects to a red wire that runs to the fuse box acc & batt terminals and it looks like it runs to the ignition switch?
So it looks like i might need to move the head light switch wire to the load black side of the ammeter gauge and to run the relay to the Alt stud instead of the pos side of the battery?
Honestly i thought they were all hots and could be put together.
Starting to understand how it works from what your telling me.
So again, the red side of ammeter gauge should be ran Alone straight from battery and the load side is the black side which goes to head light switch and fuse box accessories?

 

[72RoadRunnerGTX]

“Ok ,so running the wire from the red pos side to the relay is wrong to run it from the Alt stud? 1) please confirm this is ok”

What I’m saying is it is unnecessary for a stock sized alternator, stock loads, bulkhead by-pass, and good ammeter connections. Seams to be pushed as an alternative to correcting the real issues, defeats the purpose of the ammeter.



“I noticed the battery pos & starter relay was getting warm when i had the dash gauges out and put the ammeter wires together for test and run purposes to move the car around.
I thought that is how to by-pass the gauge. put red & black together "both hots"
Since putting the gauges & ammeter back in, they seem not to be getting warm now.”

Yes, that is how you can operate the vehicle with the cluster removed


“I did run the headlight switch Wire to the red side of the ammeter. your saying no good? to run it to the black Alt "load side"?”

Running an ammeter? All loads need to be on the alternator side of the ammeter, as is the factory B1 headlight switch power source.

“When i bought the car the by-pass outside the fuse box was already done.
They had a Red pos wire running from the starter relay straight to the red side of the ammeter gauge and is still like this. please confirm this is ok?”

Perfectly OK


“A black wire comes from ALT stud "load side" to that soldered block in the Harness above the steering column and the black side of ammeter is this a factory soldered taped connection?”

Technically, the factory used a “wire weld” process, not soldered, for the harness splices.


“So it looks like i might need to move the head light switch wire to the load black side of the ammeter gauge and to run the relay to the Alt stud instead of the pos side of the battery?”

Headlight relay if you are planning that modification, and any other aftermarket loads, not the starter relay.


“So again, the red side of ammeter gauge should be ran Alone straight from battery and the load side is the black side which goes to head light switch and fuse box accessories?”

If you want to retain the correct functionality of the ammeter, only the battery should be on the battery side of the ammeter, all loads and the alternator should be on the alternator side of the ammeter. The ammeter is designed to monitor the battery charge/discharge rate only. On a heathy system, should be little to no current flow registered while in operation, centered. Any loads placed on the battery side will register as false charging current.

 

[i_taz]

Not sure if I'm jumping but I tried this when upgraded to a 100A alt. since the battery feed side of the bulkhead was starting to burn. Theory was that more amps would charge faster lessening heat issues with a slow charge. The opposite has happened. Takes longer to charge and when I turn the headlights on the thing starts charging like crazy and that's with the headlight bypass relays...???

I'm ready to undo it and run straight to the starter relay but would like to keep the ammeter
functioning...

 

[72RoadRunnerGTX]

Not sure if I'm jumping but I tried this when upgraded to a 100A alt. since the battery feed side of the bulkhead was starting to burn. Theory was that more amps would charge faster lessening heat issues with a slow charge. The opposite has happened. Takes longer to charge and when I turn the headlights on the thing starts charging like crazy and that's with the headlight bypass relays...???

I'm ready to undo it and run straight to the starter relay but would like to keep the ammeter
functioning...

A higher capacity alternator is not going “charge faster”, the battery charge rate is determined by the current battery state of charge. If the alternator can’t keep up with the vehicle loads and whatever the battery wants, then the charge rate will be reduced. The battery charging rate is not what causes heat, current and resistance causes heat. Bypassing the bulkhead, as somewhat correctly diagramed, removes the resistance of the Packard terminals in the bulkhead, the weakest link in this charging system by far, has been since these cars were new. The primary benefit from running a higher capacity alternator is more available current at idle over stock rated alternators.

Headlight relay modification? Ammeter shows additional charging with the lights on? Sounds like you have the power to the relay secondaries connected directly to the battery/starter relay (as incorrectly diagramed above for a vehicle running an ammeter). This will cause a false charging indication on the ammeter as the headlamp current is drawn through the ammeter from the alternator while in operation. The battery charge rate is not changing. Connect the relay power to the alternator stud or another location on the “alternator side of the ammeter” as are all other factory loads.
Again, "if you want to retain the correct functionality of the ammeter, only the battery should be on the battery side of the ammeter, all loads and the alternator should be on the alternator side of the ammeter. The ammeter is designed to monitor the battery charge/discharge rate only. On a heathy system, should be little to no current flow registered while in operation, centered. Any loads placed on the battery side will register as false charging current."

 

[Old Mopar]

I see bare wires, poor/dangerous electrical connections and workmanship that needs refinement. It appears no one is an electronics technician or engineer. I see a car fire coming soon at this point

The alternator bypass 12 or 10 gauge wire should have heat soldered wrapped terminals and connections for the fusible link at the stater relay end. Using the bypass cuts the current flow thru the ammeter in 1/2. The ammeter is an indicator gauge as it does not show the current in amps so it is still reading correctly. Do not use quick disconnect connectors unless it is designed to carry a current load. Terminal strips come in many forms as do power posts
The large black and red wires that feed thru the bulkhead connector need to be removed from both side of the bulkhead and hard wired together properly thru the firewall.

good wiring parts
more good wiring parts

 

[72RoadRunnerGTX]

The wiring diagram included in post #17 appears to be one of Nacho’s, from the B-body/Charger forums. I see where it could be easy to do but consider it a band-aid fix to leave the original run in place. I agree, a quick disconnect there is unnecessary and only introduces another potential point of failure if the disconnect is under current rated, as most are. On my builds, I only run 8ga straight from the fusible link to the ammeter and replace the original 12ga run with an 8ga direct run from the alternator to the ammeter, via firewall gromet. Leaving in place, at the ammeter, the original dash harness black ammeter lead, to feed the factory loads.

The diagram also indicates a parallel by-pass of the original alternator to, bulkhead to ammeter. This reduces the current through the bulkhead connector only, will not alter the ammeter accuracy. The straight alternator to battery/starter relay by-pass some suggests does affect the ammeter accuracy, may or may not be by one half. In Parallel circuits, each leg of the circuit would have to have the exact same voltage drop for it to be one half, not likely to achieve this with different sized wiring and crusty bulkhead connectors left on one leg. The ammeter would be rendered effectively useless. Yes, the E-body ammeters is not scaled in amps, however the movement used in this ammeter is the same movement used on other Chrysler platforms of the time, some are scaled to 40amps one way or the other. Some Police applications used the same movement with an internal shunt and are scaled to 80amps each way.

Most electrical professionals will advise not using parallel runs in these types of circuits, difficult to predict current loads on each run and are difficult to troubleshoot later.

The pictured vise-grip clamped to the ammeter leads screw & nut, appearing to touch the steering column support bolt head startled me a bit, assuming the battery was/is not connected.