Bad Ford resistor

butch27 · September 14, 2009, 11:13:10 PM

P.S. It IS wired as above pic from Wayne.

wayne petty · September 15, 2009, 12:01:59 AM

take your test light...

hook it to ground... touch the I terminal with the wire to it disconnected..

hook it to power... touch the I terminal with the wire to it disconnected...

it should not have any continuity at all .. to either side... unless the solenoid is powered up... with the wire to the I terminal wire removed..

then ... hook the test light to ground again.. probe the I terminal.. have somebody turn the key to crank the motor... when the solenoid is powered.. there should be battery voltage on the I terminal with the wire disconnected..

the only thing i can thing of that will burn the ignition resistor ..

when the I terminal does its trick and welds its self to the contact disc... this keeps it connected to the starter input wire.. so there is a HUGE DRAW going down the bypass as it is trying to power the starter..

did you ever find a part number for the starter relay.. there are several versions... some of them are wired different internally...

38HAULR · September 15, 2009, 01:25:36 AM

Assuming all wiring is correct ,my bet is that the solenoid is crook in that there is a winding fault or ground leakage via the "I' terminal.
If there is a fault with not running properly with the terminal connected,this would account for resistor burn out also .
In normal run mode this terminal will see the coil +ve voltage by its connection to that terminal as it is now floating.
Being the source of 12v in normal run mode due to an internal problem should not burn the ballast ,all that will happen is that the coil is running on over voltage and will run hotter,remember it is an 8v coil.
I would say a ground path via the solenoid causing the prob.
With a 12v test lamp, or multimeter on amps, with the wire disconnected at the "I" terminal ,place one lead of the lamp on bat POSITIVE with engine running or ign "on" and the other lamp wire on the bare "I" terminal, the lamp will light or current indicated if there is a short.......Frank.

GPster · September 15, 2009, 08:37:31 AM

Quote from: "butch27"O.K. This is weird. I put on a new solenoid and it still wouldn't start. Then I disconnected the "I" wire completely and the darn thing runs great. But I'm afraid I'll burn the points up??Ideas??

New or different? I come up with the same conclusion that wayne and Frank and Frank come up with but it seems unlikely that two solenoids would fail the same way. You shouldn't have needed too many wires to run an engine with points in a "T". Keep us posted. GPster

butch27 · September 15, 2009, 09:23:52 AM

NEW-- and I'll test the way they said today. Thanks Everyone.

38HAULR · September 15, 2009, 05:21:06 PM

butch, was this ever running before ok and developed a fault,or is it a new build vehicle?........Frank.

38HAULR · September 15, 2009, 05:26:47 PM

Quote from: "enjenjo"
Quote from: "38HAULR"The ign feed to the coil via ballast is still present on cranking . ....Frank.

Not always. Many GM cars are wired with ignition power on a seperate circuit when cranking.

.
Any logic to this enjenjo?.
I am familiar with the lack of a bypass cct in electronic ignition setups that do not use a ballast because they are running at full12v
Frank

butch27 · September 15, 2009, 05:53:55 PM

Yes it was running great for 3 test runs. And it started on the first try each time from outside the car.

enjenjo · September 15, 2009, 07:01:12 PM

Quote from: "38HAULR"
Quote from: "enjenjo"
Quote from: "38HAULR"The ign feed to the coil via ballast is still present on cranking . ....Frank.

Not always. Many GM cars are wired with ignition power on a seperate circuit when cranking.
.
Any logic to this enjenjo?.
I am familiar with the lack of a bypass cct in electronic ignition setups that do not use a ballast because they are running at full12v
Frank

No idea why Frank, but I have run into this on several GM columns from the early 80s.

38HAULR · September 15, 2009, 08:15:01 PM

Ok Butch. One more "experiment" to isolate things. Disconnect the wire from the "I" terminal of the solenoid at the solenoid.
Disconnect the wire that goes to the "I' terminal of the solenoid from the coil +ve .
This now leaves you with the coil +ve only going to the ballast only and you have your running vehicle which is already established as previously described.
Can you now grab a spare piece of hook up wire you may have lying around and connect this between the "I" terminal, and the coil positive, and then see what happens ,start/run .Reason for this exercise is to isolate any "funnys" that may involve your vehicle loom.........Frank.

butch27 · September 16, 2009, 11:07:24 PM

Guys: I did all of the checks and everything checked fine. Made a new wire from "I" to coil and move the "I" wire from where it was connected to coil(right at the coil Pos and moved it to come in at the resistor first . I worked!! Don't see how it made any difference - the both end up at the same place

Thanks Everybody.

38HAULR · September 16, 2009, 11:51:04 PM

Butch to work correctly the "I" wire should go to the coil +ve ,it,s purpose is to deliver full available volts during cranking, by passing the ballast......Frank.

enjenjo · September 17, 2009, 01:11:31 AM

Is this an original wiring harness, or a rewire? you are aware that most Fords in the 60s had a resistor built into the wire to the ignition, and dis not use a ballast resistor.

38HAULR · September 17, 2009, 05:20:18 AM

I was under the impression that the resistor that was "smoking and burning up" as described in the initial post, is the old external wire wound on the ceramic former item.......Frank

butch27 · September 17, 2009, 08:50:04 AM

Yes I knew that Ford used a wire resistor. I don't like those so I used the external style and my coil says you must use an external resistor.(I used the universal Chrysler) I tried the wire going right to the coil and the resistor wire hooked to the same POS terminal but thecar wouldn't start. Switch ed the wire to the resistor with a jumper to POS ont the coil and it runs now. What have I got here? LOL