Rsistor Wire

Post your technical questions and information here.
GrantRees
Posts: 24
Joined: Wed Oct 07, 2015 12:11 pm
TOA Membership Number: 0
Years Owned: 1969 Toronado
Location: Vermont

Rsistor Wire

Postby GrantRees » Sun May 21, 2017 7:21 am

Hi All:

Still working on the '69 Toro. Floor pans patched, new carpet in. While the motor was (is) out I ditched the points for a pertronix hall effect trigger. Now I've gotta find and bypass the resistor wire to get 12 volts to the distributor / coil. I did this on my '69 F-250 and it was a minor PITA finding a power source inside the cab that didn't cut out when you hit the starter. Got it done and it's worked great for several years which is why I made the switch on the Toro.

This time I'd like to just bypass the resistor wire than find a new power source or run an independent switched circuit from the battery or what appear to be the first major relay (horn and seat I think). To that end does anyone know exactly where and what color the resistor wire is? I have the service manual and while it has a pretty clear schematic finding the wire in the real world can be a different matter. any insight or help would b greatly appreciated.

Getting closer to getting off the lift and on the road: motor needs to go back in (and start) - replaced lifters, rocker, push rods, oil pump, fuel pump, distributor and point as noted above. Bench seat needs to go back in - but I'd like to solve the resistor wire thing first while I can stretch out on my back while working under the dash.

So, there you have. thanks for any help.

Grant

Schurkey
Posts: 158
Joined: Fri Aug 14, 2009 8:28 am
TOA Membership Number: 67

Re: Rsistor Wire

Postby Schurkey » Sun May 21, 2017 5:46 pm

If you have the service manual, it should show the exact cavity in the bulkhead connector you need to deal with. Remove engine-compartment-side bulkhead connector. Pop the original resistor wire out, plug the new wire in. Reconnect bulkhead connector block.

There are companies selling the 12-gauge wire you need, complete with the Packard 56 connector at the bulkhead end, along with a molded-plastic connector on the other end intended for direct connection to an HEI distributor. You'd cut that end off and splice it to whatever wire the Pertronix uses. Sorry, I can't find a link at the moment.

GrantRees
Posts: 24
Joined: Wed Oct 07, 2015 12:11 pm
TOA Membership Number: 0
Years Owned: 1969 Toronado
Location: Vermont

Re: Rsistor Wire

Postby GrantRees » Mon May 22, 2017 3:40 am

thanks for the input. Got in to it yesterday. Peeled back the harness tape and was going to trace the wire back, replace the wire and re-tape. Before cutting anything, though, I hooked up the battery and took a reading at the positive coil terminal end of the wire. 12 volts. A bit surprising since the car had points before I replaced them. The wiring under the hood probably is not original to the car. It appears I don't need to replace. The wire running to the coil is white with black markings and cloth over the plastic. I assumed it was resistor wire given the cloth outer covering, but the mulitmeter say 12 at the pos. terminal of the coil which is what I want.. I think

Thoughts?

Cheers

Grant

bcroe
Posts: 305
Joined: Thu Nov 15, 2012 12:25 pm
TOA Membership Number: 378
Years Owned: 79 Toronado or Eldorado

Re: Rsistor Wire

Postby bcroe » Mon May 22, 2017 7:01 am

GrantRees wrote:Before cutting anything, though, I hooked up the battery and took
a reading at the positive coil terminal end of the wire. 12 volts. A bit surprising since
the car had points before I replaced them. Grant


It will read full battery if the points are open. Check that the other coil terminal
reads 0V (points closed) when making your test. Or just short that terminal to
ground for the test. If you actually had no resistor, it would burn out your points
a lot faster; maybe even be a hazard. Bruce Roe

GrantRees
Posts: 24
Joined: Wed Oct 07, 2015 12:11 pm
TOA Membership Number: 0
Years Owned: 1969 Toronado
Location: Vermont

Re: Resistor Wire

Postby GrantRees » Mon May 22, 2017 5:25 pm

I had not thought of that. The motor is out of the car so I just hooked up the battery, switched on the ignition and took a reading at the lead that hooks to the pos coil terminal. I'm not clear on why that would be but don't doubt the suggestion. I'll hook up the battery attach the pos. coil lead and ground the negative terminal and see what's what. I guess I don't fully understand the physics, for lack of a better terms and simply assumed that the resistor wire would show reduced voltage regardless of points position or, as in my case whether the distributor was even present.

I simply assumed (ass of you and me) that the PO cut it out in hopes of getting more punch out of the motor. I lost the ballast resistor in an old V-6 Jeep I had as a young man. I bypassed the ballast resistor to get it home, and it had a lot more punch than before failure, perhaps obviously, but more still than when I replaced the failed resistor with a new one. this is the same PO the simply cut the out (not removed and capped) a good portion of the AC system, ostensibly for more "go".

Anyway, I'll give that a go and see what happens. Any insight as to how long / what color the resistor wire is and will it be obviously different that the remainder of the wire. As I recall my F250 i could see the resistor segment in the wire, I think, memory can play tricks. I'm ot finding a picture or good description in the shop manual I have as to where exactly the resistor portion is located. I have noted, though that there is no wire matching the one leading to the coil among the wires coming off the steering column.

Thanks a lot for the insight. Probably saved me a lot of motor won't start frustration once I get it back in the car.

Cheers.

Grant

Schurkey
Posts: 158
Joined: Fri Aug 14, 2009 8:28 am
TOA Membership Number: 67

Re: Rsistor Wire

Postby Schurkey » Tue May 23, 2017 11:37 am

The resistor in a GM is the wire itself. There is no bigass ceramic block like a Chrysler or Ford.

A resistor primarily acts to reduce the current) (amperage) flow in a circuit. They only reduce voltage when current is flowing. If the points are open, no current flows, so voltage is not reduced. When the points close, current flows, and voltage downstream of the resistor drops.

GrantRees
Posts: 24
Joined: Wed Oct 07, 2015 12:11 pm
TOA Membership Number: 0
Years Owned: 1969 Toronado
Location: Vermont

Re: Rsistor Wire

Postby GrantRees » Mon May 29, 2017 6:45 am

Thanks for the help on this. Peeled back the the tape on the wiring some more and sure as shooting there's the junction between two red hot wires and the resistor wire. Put the ohm meter on it to verify and it was something like 1.6. Far more than zero in any case. I plan to leave the resistor wire there, splice in a length of 12 ga and run that to the coil and tape it all back up. That way if the pertronix fails or I don't like it I can switch back over to points by just switching back to the resistor wire and won't have to undo everything. I should have believed my initial impression the the white wire with little back marking was the resistor wire.

Thanks again on this. Had I not gone back and corrected this error I may well have wound up with a frustrating "no start" situation when I put the motor back in.
Attachments
IMG_0697.JPG
IMG_0697.JPG (1.3 MiB) Viewed 11735 times
IMG_0696.JPG
IMG_0696.JPG (1.27 MiB) Viewed 11735 times
IMG_0694.JPG
IMG_0694.JPG (1.87 MiB) Viewed 11735 times

NRGF
Posts: 42
Joined: Fri Oct 16, 2009 1:55 pm
TOA Membership Number: 40
Years Owned: 1969
Location: The netherlands

Re: Rsistor Wire

Postby NRGF » Mon May 29, 2017 12:34 pm

Changed my 69 Toro to the Pertronix system about 16 years ago, no cleaning or adjusting and hasn't missed a beat since.


Return to “Technical Talk”

Who is online

Users browsing this forum: No registered users and 20 guests