won`t start

[madman7]

I need help! I left my lights on on my explorer. Got a boost, wouldn`t start. jumped the relay truck started. Drove home shut off truck wouldn`t start. So I changed the battery, the starter, and the relay still won`t start. If I jump the relay truck starts. Also there are no warning lights on dash.
One thing I find a little curious is when truck is off the four-way flashers come on and my alarm system warning light flashes rapidly. Since I bought the truck with the alarm I`m not sure if it has a starter interrupt. Does anyone have any ideas what might be going on.

 

[jgilbs]

why dont you just replace the starter solenoid?
also, check the condition of the wires leading to the starter for corrosion, loose/dirty terminals, etc.

 

[madman7]

Idid replace starter and solenoid. If it was the wires the truck should not start when i jump the relay.

 

[jgilbs]

well if the wires to the solenoid from the batt are corroded it could cause this. it is a very common problem on 1st gens. does it even click when you turn the key? if not, its possible you have a bad ignition cylinder(or the wiring to it) or like you said a starter interrupt doing its job.
to find if your truck has a starter interrupt, find the starter wire under the dash and trace it towards the firewall. if you see it interrupted by a relay, bypass the relay and try again. it will be pretty obvious what is OEM and what is to your alarm(look for wiretaps, heatshrink, elec tape, etc on the wire.) once you solve this, if you never use your alarm, youre best off removing it, since it will only cause problems. but if you dont know what you are doing this can cause more problems.