i have a 1989 f150 with a 300 I6 5 speed and the other day i killed the battery. i have a set of boster cabels that are backwards at one end (for our old tractors with positive ground) i know that they are backwards but my buddy was hooking up the cabels and he hooked them up like they are supost to be. i went to crank it over and all my gauges went all weird then i heard this POP! under the dash. so i realised what made all the gauges do that but now i charged the battery and it will crank over but the fule pump is not kicking in so it wont start. my uncle was saying there will be a main fuse or something like a fuseable link that will cause that to happen but i dont understand how it will still crank if the main fuse is poped or evan where to look for it on the truck.

so if someone could help me out with finding out where the fuse is or what could be going on that would be great.

thanks kyle.m

 

Your electric fuel pump will have a fuse/relay/fusible link, get under your dash and start looking. It will crank, because they are separate circuits.

 

My guess is the pop came from the EEC Computer and it will need to be replaced.
You will also need to check the fuse links coming off the battery side of the starter solenoid.

 

ya im pritty sure its my computer because i went out today and checked all the fuseable links and they were all good. the pop noice being the computer would make sence cause it came frome that area of the truck.

i forget to mention when i turn my key to the run position it sais engine then when i turn the key off it put a light on that sais check engine witch i would imagin the computer being screwed up would do that.

 

check engine light is supposed to come on when you turn the key to run without the engine running. If it where me I would get a manual and check everything before I shelled out $100+ for a new computer. Sometimes you can't just look at fusible links and tell they are bad. You need to use a DVOM and check for power on both ends or Ohm them out.

 

This is what my 1990 Service Manual says: The fuse link used on the Bronco, E-150--E-350, Club Wagons and F-150--F350 and F-Super Duty trucks, is a short lenght of insulated wire integral with the engine compartment wiring harness. It is several wire gauges smaller thatn the circuit that it protects and is the color of the circuit being supplied by the fues link. Service suse links are green or black depending on usage. Al fuse links have a flag moulded on the wire or on the terminal insulator. Color identification of the flag or connector is Red-18 guage, Orange--16 gauge wire, or Green 14 gauge wire

The fues link is designed to burn out, thus protecting the alternator and wiring when heavy reverse current flows, such as when a booster battery is connected incorrrectly, or a short to ground occurs in the wiring harness.

A burned out link may have bare wire ends protruding from the insulation, or expended or bubbled insulation with illegible identification. if it is hard to determine if the link is burned out, perform a continuity test.

Yeah, those tricky electrical parts, when the smoke leaks out you gotta replace the part.

 

i checked all the fuseable links coming out of the starter solinoid with my multimeter checking for continuity and they all had continuity going trew them so unless there is some some where else im thinking it is the computer but im guna look into it a bit more before i buty a new computer

 

Agreed with computer. If you pull the computer out and open the casing on it (a few torx bolts) you might be able to see where it 'popped' at. I blew the ignition part of my computer once so it cranked but never started.

 

were you abel to fix it or just see where is "popped"

 

I replaced it. It could have been sent out (I think there is a good place in Canada) but I tracked down a new one (which was hard to find cause they had every serial number but the one I needed) and put it in. Fired right up.

But, it could be repaired. Im just not very good with little electric circuits and soldering...

 

i found a truck the same body style as mine with a 300/ 4.9 in it the only thing difrent is it is a auto not a standerd....will it still work in my truck?

 

What year was the truck it came out of and what transmission did it have?

 

is this the computer or ecc in my truck? (clickable thumbnail)



i thought it was but i put another one on and its doing the same thing as before and i opened up the old one and it sais rear anti lock on the electrical bord

 

The computer should be a metal box (silver, gray?) in the driver side kick panel. Take off the interior trim under the driver side dash on the left side and it should be bolted up in there. Its probably like 6 inches or something by 4. I dont know, buts its bigger.

 

does not look like the computer to me.