88 F150 electrical issues

I'm all of a sudden having issues with my 88 F150 (4.9, 5 sp., 2wd). I had been running it for 1/2 a day stopping here & there on Friday, and when i was at my in-laws house, when i went to leave the battery was dead. (less than a year old too) after putting in a new battery (everything clean, bright & tight), I drove to the farm, and then home for the night.

Yesterday morining I again took out my truck to run a few errands, and when I came out of the bank, I got nothing again. It didn't take a jump the day before, so Dad and I just towed it back hto the farm instead of messing around with it because we had other places to be. I put his charger on it(newer one that will test your batteries), but it said it was good and checked out with 12.6 volts. Left the charger on 2 amp charge overnight but still nothing. The dinger will sound with the key in when I open the door, but turn the key and it looses everything.

Anyone have this happen? Ideas? Probably gonna tow it to a shop tomorrow after work, but it'd be nice if there was something I could check out first. I need it to haul a load of hay and the garden tractor back to the farm by the end of the week.

Donovan from Wisconsin

sound like the ignition switch,located on the
colum under dash

Start looking at the starter and plan on replacing it. Rock auto is a cheap source. Don't be surprised if your starter just kicks in on it's own or don't cut off when you release the key.

But first, check that the ignition switch on the steering column is in the right position and tight (not slipped a little and leaving your key on).

I think your starter is starting to short out inside. Had the same problem on a 90 with 5.0 bosch starter.

Ford solenoid switches (on fender) can fail suddenly. Test by jumping large terminals to see if it will crank.

You say the door dinger sounds 'til you rey to start it. ASSUMING the battery is good the MOST likely problem is a poor connection at the battery, either between the cable ends and the posts or INTERNALLY in one of the battery cable ends.

The latter is COMMON on Fords in that era... the lead at the battery end of the cable (USUALLY +) becomes disconnected from the wires inside and a poor connection is made only through the lead oxide and acid 'til a load is thrown on it, then it "opens" without cranking the engine.

The test is to put a test light ACCROSS the 2 battery POSTS and see what happens when a helper tries to start it... if the test light remains BRIGHTLY lit, the battery is OK.

Then, move on and connect the test light between a good ground on the engine and the battery cable-side terminal on the starter SOLENOID located on the fender. Does the light light and remain lit while the helper tries to start the engine?

If NOT it's a battery cable problem and you need to do some more checking with the test light to see where the "open" is!

Post back with what you find!

BTW, I'd wear eye and face protection while working around that questionable battery and possible (sparking) poor connections near the battery.

Before you spend a bunch of money look for a fusible link. Some times they can burn into but carbon trace inside the insulation untill they are Frank

My 89 did the same thing on occasion. Took getting new 0 gauge cables to fix it. I also had the starter switch under the dash go and do the same thing.

Check where the ground cable hooks to the starter, a little crud there is very common.

put a new oxygen sensor in it , along with a fuel pump

had a 87f150,occasoinly the same problem. the ground
cable worked loose at the starter. fixed it
everytime.

I had this same problem on an 85. Wire seems to work loose easily.

Had a similar problem on my 91 F150, same engine and trans. Turned out to be a master control relay not disconnecting contacts when ignition was turned off. Kept power to the fuel pump, etc. when turned off. Relay is located in a bank of other relays, fuel pump relay etc. on fender well. Cost $8 and never had another problem.

Think I found it. I took the cables off and put them back on, and it started. I went to Bumper to Bumper (closest place open on Sunday) and they were useless. Weren't able to tell me how long the cables were supposed to be, and what they had for selection sucked, with most having really cheesy pressed steel clamps.

I then went to Autozone, and they happen to have several old timers there. They were able to look in the computer and tell me the lengths needed, and helped me out with pretty good service.

I only replaced the positive cable for now, being that the wind was kicking up really bad and I didn't want to crawl underneath to mess with the one on the starter. So far so good, and hopefully I found it. Now I gotta figure out where I can keep the other battery from my truck until one of the tractors need one.

Donovan from Wisconsin

Point to point troubleshooting. Just like Bob said. Start with starter circuit. Dave

Point to point troubleshooting. Just like Bob said. Start with starter circuit. Dave