1978 F-150 odd starter issue

Asked by Dec 04, 2017 at 11:50 AM about the 1978 Ford F-150

Question type: Maintenance & Repair

I am rehabilitating a 1978 F-150 (300ci straight 6, 4WD) and I am having the oddest starting problem. The engine will start and run only as long as it is being cranked. When the key goes back to the run position, no ignition and engine shuts down.

Things I have done:
1) Replaced starter (it was seized up)
2) Replaced solenoid (just because)
3) Replaced the big fuse that is screwed to the body next to the solenoid
4) Yanked out the ignition switch and checked its function
5) Traced wiring continuity to and from the starter switch

I'm sure that the problem has a simple solution, but I am at wits end trying to figure out what is going on. It seems like there is no juice coming out of the "I" terminal on the solenoid. If I short the S and I terminals when someone is cranking it, it starts up and stays running, but the starter keeps going so I obviously can't leave it like that except for test purposes.

2 Answers


I think your ignition switch is faulty.

I ran a continuity tester over the contacts in all positions and they match what they are supposed to according to the guide I found. Next on my list is to manually connect terminals in the ignition switch socket with jumpers and see if that makes any difference.

Your Answer:

Ford F-150 Experts

  • #1
  • #2
  • #3
View All

Related Models For Sale

Used Ford Mustang
45 Great Deals out of 1,559 listings starting at $2,400
Used Ford F-250
6 listings

Used Cars for Sale

2019 Ford F-150 For Sale
102 listings starting at $50,924
2018 Ford F-150 For Sale
14 Great Deals out of 8,310 listings starting at $12,550
2017 Ford F-150 For Sale
10 Great Deals out of 394 listings starting at $27,955
2016 Ford F-150 For Sale
17 Great Deals out of 985 listings starting at $18,997
2015 Ford F-150 For Sale
15 Great Deals out of 495 listings starting at $17,998

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.