No power at the ignition switch

[The Risleys]

I have a 1970 Winnebago with a 413 on an M-300 Dodge chasis. After a carb rebuild, gas tanks dipped and cleaned and the distributor upgraded to electronic, it was still running pretty rough. I had to jump it to get it started, so I tested the high RPM output and it was below 11 amps. I then replaced the altenator and bought a new battery. It ran for approx. 20 miles before we lost all power. No gauges, no lights, nothing! Realized I should have replaced the voltage regulator (alternator regulator), but even after doing so there is still no power. Can't really find any loose wires, jumped the starter and that works fine. Does anyone know where I can find the schematics for the starting system and charging system? Any help will be grately appreciated. Thanks! -DGR

[DaveVA78Chieftain]

A link to the Dodge chassis schematics is at top of the page, Members Area, Free Manuals. Under the chassis column of the Chassis & Coach Wiring section for 1970.

You can also puchase a 69-77 MH service/parts pdf manual from the store for $20.  They schematics are in the back of section 8.

Dave

[The Risleys]

Thanks Dave. I found the schematics. Replaced the starter relay, still doesn't work. Thinking about replacing the ignition switch. Any ideas on what else it could be? The beast broke down in the middle of vacation. I just want to get it home! I don't want to give up on it yet, but it's driving me crazy!

[DaveVA78Chieftain]

You either need a test light or a voltmeter to help isolate this rather than throwing parts at it.
For reference: Wire numbers on the schematic like S1(10RE) mean it is circuit S1 using a red 10 gauge wire.

Dodge Amp meters are a known weak link.
B+ tapped off at starter relay is feed directly to that meter via wire S2(10RE).  There is an inline connector on that wire (most likely on driverside floorboard area) that connects to wire S1(10RE) which connects to the  Amp meter in the dash.  If amp meter is dead no voltage will get past it.
Output of amp meter is feed to over wire A1(10BK) to a junction which feeds:
A) Ignition switch - A20B(10BK) to a connector for A20A(10BK)
B) Fuse block, Tail/Stop/Dome/Park, 20amp - F42A(10RE).  Output of that fuse [F47B(10PK)] goes to the headlight switch so, if no headlights then no juice from amp meter.
C) Fuse Block, 4 way flasher, 25amp fuse - F42B(12BK).  Output of that fuse goes to 4 way flasher so, if no 4 way flasher then, no juice from amp meter.

There is also a 2nd tap of the amp meter going to the headlamp switch relay [F42D(10RE)]

Those are all clues about which direction to go.  If all those are bad, then it's down to the amp meter or the cabeling leading back to the starter relay (driver side frame rail, inboard).  You use the test light or meter to determine if voltage is at the different points.

If you determine the amp meter is bad, then you can just short the S1/A1 leads together to get it running again.


Dave

[The Risleys]

Dave, Thank you for the suggestions and what to look out for.
I still have not found the problem.  i can't get power to the amp meter. I also have not found any fuseable links in any of the ares that they should be. with the key in the on position or the start there is no power running through the ford style solenoid in the battery compartment. nothing at the rely or at the starter.

[DaveVA78Chieftain]

The path I gave you above is how battery B+ gets to the ignition switch NOT after the switch is ON.   The Dodge drawing does not indicate there is a fusible link for 1970.  If one has been installed, it would be at the starter relay mounted on the frame rail.  It would be attached to the S2(10RE) lead I referenced .  The S2(10RE) lead will lead directly to the battery as it connects to same post on starter relay that the large B+ battery cable attaches to.  So, you essentially have a wire from the battery directly to the Amp meter.  If the wiring is good to the amp meter then the battery is dead.

Dave

[salplmb]

i hate to admit it but i had a problem like that. went through everything and could not figure it out. finally realized that the motor died while in gear. the thing wont start if its still in gear. no power at the key. duh! happens to the best of us. hope u have luck figuring it out.
sal

[The Risleys]

Thanks to all with the advice and comments.
Dave I ended up starting from the starter relay and following the lead to the dash and unravelling the loom. found a circuit breaker box that had really bad wires.I try to get a pic of this.i also had a dead coil to distributor wire and a dead ballast resistor. All i can say, is we have been lucky we haven't had a fire. So the relays and voltage reg, and a circuit box and ballast and an alt. and battery. Its funny how my gauges and lights and things are working a lot better too. In the morning i will test drive before making the last 150 miles of our trip home.

[DaveVA78Chieftain]

Good to hear you were able to work it out.  Sounds like some things were already on the last leg and you ended up pushing them over the edge.

Dave