Cruise Control issue - F-100/SC

jclars

Registered User
Been awhile since I have posted, as my SC transplant into the F-100 has been well behaved. Lots of trouble free miles! I lost my CC awhile back and am just now digging into it. I know, who needs CC on a rat rod pick-up, right. But I miss it!

I first checked the brake switch, using a MiniVac and it was functioning fine. Checked the vacuum hoses and added clamps, although leak testing there didn't reveal anything.

Lastly, I tested resistance at Connector C182 behind the steering wheel. All was nicely in range except "Resume" did not register anything. (sb 2090-2310 ohms).

My EVTM refers me to Section 37 of the "Shop Manual". Does anyone have a link to this section? Or experience with this fault?

Thanks for past and present help!

John
 
When section 37 (34 pages) goes to testing, it refers to codes (among other things...the testing section alone consumes 22 pgs.) - have you run them yet?

Otherwise, and in lieu of anything actionable, I'd start by resocketing any participating connectors, being sure to dab in small amounts of connector grease and taking care to confirm they are fully plunged, etc. Add tie-wraps to any that need help coming together, while removing any corrosion you can spot and reach. Replace any connectors that won't cooperate and/or look to be hiding damage/corrosion. Don't forget to do the same with any grounds you can reach in the process.

Frequently just fondling a connector can help to at least temporarily restore functionality - ask me how I know ;) Hint: cooling fan

Ken
 
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Hi Ken - I remember leaning on you quite a bit during my build! Glad you are still around!

I did poke a screwdriver at the terminals to seat them and finally got a reading in range for the "Resume" switch.

I have a mess of wires up under my dash, some still in original wrapped pigtails. However, I kept routing the same as for the SC. Do you know which direction it heads from the steering column? (The one lead appears to go to the main computer, thats the Lt Blue/Blk wire.) Or does it go to the servo and then back? Trying to trace the whole line.

Much more accessible than under the T-bird dash I must say...

John
 
Trying to trace the whole line.

EVTM is your friend ;)


Do you still use the multi-wire/function ignition switch* down on the side of the steering column? It can be root cause for many electrical issues....I'd focus on it.

No codes?

EVTM 31-1 Speed Control

Switches (steering wheel)
...EEC --|-- Speed Control Servo Motor/Pedals/Start~Ignition
................Power Dist Box (under hood)
.........Pedals as applies
........................Anti-lock control module
...............Primary Junction Block
..................Start Ignition
........................Stop Lamp Switch
...........................Primary Junction Block
..................*Multi-Function Switch
 
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EVTM is your friend ;)


Do you still use the multi-wire/function ignition switch* down on the side of the steering column? It can be root cause for many electrical issues....I'd focus on it.

No codes?

EVTM 31-1 Speed Control

EVTM page 70 simply shows two wires heading to ECA terminals 39 and 28. Can't tell if it is a direct path, but it looks like the wires for the ECA all head toward the RH front side of the truck. While C182 connector is on the LH side.

That was more the question I had - where do these come/go without unwrapping the wire looms to find them?

Thanks!
 
My '90 EVTM has sections...there is no '70 - it jumps from VMM 68-4, to 71-1 Instrument Illumination.

Speed Control is 31-1; it's main components reside inside the driver's side fender; harness connects at the firewall (C103) then goes along the inside of the fender, then splits generally behind the left headlight at connector C502, in front of the battery, I think in front of the header, where it makes a tight turn and snake in and out of the header and fender, where it connects to the servo (LH Front of Engine Compartment, behind fender), outboard the battery's location.

Component locator 151-2 D-9

Locator PDF here (1989): http://www.sccoa.com/forums/showthread.php?61769-Component-Locator&highlight=component+locator

I show C182 LH side of I/P, near steering column.

My EVTM shows these #s for speed control at the EEC:
3 (DG/W), 5 (LG), 28 (LB/BK), 51 (GY/BK), 35 (W/PK), 11 (O/Y), 6 (BK/W ~ GND)

C509 LH front of engine compartment W/PK wire; C109 RH front of engine compartment W/PK wire (looks like it's near the IRCM, snaked in the header).
 
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Thanks Ken

I will give it a go. Cant think too much changed in one model year. My CC worked fine for several years. The only thing I can think back on is I pruned a bunch of wires at some point behind the glove box door.

You may identify a few familiar SC pieces inside the cab of this old truck! I located all SC components in the same location on the truck as in the SC, including servo and battery. So tracing based on your descriptions should help find the missing link, if there is one.

20180601_165524.jpg
 
Sorry I can’t really help with the CC issue as I’m not to hip on these systems but as an F100 and an SC owner I love the swap
 
You may identify a few familiar SC pieces inside the cab of this old truck!

Yes, John, a couple ;)

Tell you what, drop the truck off at my place in Salem and I'll sort it out for you while I wait on fresh heads for my '90...

Ken
 
I am headed down that way next Friday, staying in Medford the first night. Going to pick up a Model A basket case in CA. This one will be a bit more traditional and get a Flathead V8 however.
 
I am headed down that way next Friday, staying in Medford the first night. Going to pick up a Model A basket case in CA. This one will be a bit more traditional and get a Flathead V8 however.

Slap some Ardun heads on it and put a "Yes, it's got a Hemi!" sticker on the bumper. :D:D

RwP
 
I don't know if you guys are familiar with the HAMB forum (Hokey ~~~ Message Board), but I left it when I did the F-100-SC build. Never did a complete build thread there, as I was told I had strayed too far from a traditional hot rod. I did my build thread on this forum as it was enthusiastically encouraged! Good job everyone!

With this Model A, I am gleaning all sorts of information off that site, but unlike here (SCCoA) I am reluctant to return, or do a build thread, because of how some members want to keep it a closed club. I get it, sort of. A goat club would not necessarily allow a thoroughbred horse to join. Even if they could maybe learn something from it (like how to run faster).

Heading out to track down some wires...
 
This one will be a bit more traditional and get a Flathead V8 however.

Last time I did a Flathead V8 swap was to a '49 F-1 that left the factory with a 6 cyl. Took about an hour all in. I miss that truck...

Good luck w/the A.
 
Marginal success. I found a cut W/LB wire in the area I had done some wire pruning. But unable to locate connector C120 to which it may have connected. Ken, do you have any source that shows what else is combined at C120?

Do colors change (ie, at C182 from BK to W/LB) between connectors? What about the gold fleck marks on the wires. Is this just a way of creating a new ID color? Not a duplicate, right?

I am going to fish in my box of saved connectors to see if I unwittingly pruned it completely out.

I traced everything from to/from servo without pulling harnesses apart. Seated connectors, etc.
 
Now that I relook at it, I see terminal 39 at ECA is a ground. At C182 it comes from the Speed Control switch as black, but turns into W/LB on the other side of the connector.

If I bypass connectors and go directly to terminal 39 and 28 at the ECA, would that isolate all I need (other than the servo conductors)?
 
C120 LB/BK - looks like one wire that sits between the EEC and the speed control switch in the steering wheel.

>Do colors change (ie, at C182 from BK to W/LB) between connectors?

Goes thru C182, same color.

EEC #28------ LB/BK--C120--LB/BK--C182--LB/BK--speed control switch assembly/slip ring


Original location pass. side dash at the firewall 'behind right hand cowl panel' - shows it coming out of a bundle that runs far right, above, then along down along the outside of the glove box opening, then forward, down , then the bundle forks out to C120 that is tagged ' to body.

No idea on gold flakes, sorry.

No idea about bypass. I'd not get creative with any wire that is directly connected to the EEC...

Do both the horn and the original cigar lighter work? They're at C182 P/O which feeds into another slip ring at the steering wheel.

C182 W/LB is on yet another slip ring.

Remind me, are you missing all cc functions, or just some? Coast/Set Accel vs. Resume vs. Off/On....? I see three resistors in there.
 
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All CC functions non-operable. Except resume. It resumes doing nothing when I push it.

Horn works fine.


No idea about bypass. I'd not get creative with any wire that is directly connected to the EEC...

Now Ken, Do I look like the sort that would take risks in this regard...

On the other hand, is there some way to detect EEC output at those terminals?

John
 
>It resumes doing nothing when I push it.

heheh

>Do I look like the sort that would take risks in this regard.

Do I seem like someone that would suggest caution casually? ;) It's not about you, it's about the ugly smelling smoke that gets turned loose when an eec fries...haven't found a way to put it back in the box yet.

>is there some way to detect EEC output at those terminals?

It's at this point things get sticky. The number of pages I referenced above lean heavily on using a breakout box. My concept of getting creative in this example is trying to t'shoot without one. Your problem is that the cc doesn't work below a certain speed (23mph?), so...without a breakout box, you might not be able to tell if a certain circuit is dead by design, or just dead.

Have you pulled the steering wheel and sanity checked the controls, wipers inside? I can list the ohms for each of the three circuits, but if you've lost them all, I doubt they're a factor.

How's the tension on the cc cable at the TB? See http://www.sccoa.com/forums/showthr...control&highlight=cruise+control+cable+adjust
 
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I have a couple of British Lucas specimens in my garage, so electrical fires have happened on my watch! One vehicle was cured by putting in a Miata engine with, yup, an ECC. No cruise control however...

I haven't given up on the idea of finding a loose wire somewhere. Too many times playing under that dash makes it a high probability.

The ohms listed for the various CC switch functions were all in range. How could I go the other direction and (safely) test each circuit for continuity?

Thanks,
John
 
By the book... (skipping visual inspection, IP testing, code reads, and quick tests)

Symptom: Speed control does not work - Code 11 ▶ Go To G

G:
Circuit - Vehicle Speed Sensor Coil Winding
Test Pin 3 & Test Pin 6
  • G1 Speed Sensor Resistance Check (involves breakout box)
  • G2 Check for Short in Sensor Input Circuit
  • G3 Check for Open in Sensor Input Circuit
G3 (skipping G1 & G2)
  • Key off
  • Disconnect harness connector from vehicle speed sensor
  • DVOM on 2000 ohm scale
  • Measure resistance between the two connector pins
DVOM reading greater than 240 ohms ▶ REPLACE speed sensor - Repeat Quick Tests
DVOM reading between 180 and 240 ohms ▶ REPAIR open in wire harness between sensor and EEC-IV pins 3 and 6 - Repeat Quick Tests
 
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