coilz

Im trying to help my brother out with his old 89 f150 300 straight 6. Its been sitting for the past 6 months and he went to throw a new battery in it and hooked it up backwards! I towed it over to my place and have gone through all the fuses under the dash and have hooked up the battery correctly. all the dash lights come on and i can hear the fuel pump prime but it wont turn over.

Is it possible the ecu is fried? or would it be as simple as a starter relay or solenoid?

Thanks Greg

dewman

When you say it won't turn over, do you mean it does not even crank? Or does the engine turn over without firing up and running? If the engine does not turn over at all, then the solenoid/starter relay (same thing) could be bad. It is the thing on the fender, inside the hood, and it only costs a few dollars to replace. If it is turning over without firing, then I am not sure what the problem is. We have some great mechanics here and I am sure one of them will eventually find your post and give you some advice.

Good luck and welcome!

coilz

Yes the motor will not even crank. does nothing when the key is turned

dewman

Do you have lights? Dash, interior, headlights, tailights, etc?

I would think to try replacing the solenoid/starter relay. If it is not closing, you won't get any juice to the starter to turn the truck over. If that does not work then you will may need to wait until someone else here, with more experience than I, can respond with some suggestions.

Good luck!

coilz

Thanks for the quick replies dewman..the truck has working headlights and tail lights and everything else in the truck works. Im going to try jumping the terminals to see if it'll start

Thanks Greg

dewman

yw!

coilz

Ended up relacing the starter solenoid and the alternator and shes as good as new.