ok i finaly got the tranny swap and the motor back together in the cherokee now i have some electrical problems would anyone be willing to help i have spent all day messing with it and cant seem to figure it out it runs and drives but it stalls when you back up some times everything looses power but it will still crank and has spark just no power to fuel pump then a few minutes later everything is ok and it runs rough please help
jeep help
- Thread starter 74highboy
- Start date
UNSTUCK
But stuck more often.
Give us some background on what you have done. Was the engine and tranny swapped from a same modle year rig? Did you have to modify any wiring to make it all work, or was everything plug and play? Is your fuel pump curcuit protected by a fuse or a braker? And your tranny is an auto, right?
its an 87 cherokee had a 4.0 and a 5 speed in it we replaced the motor and rebuilt the head i swapped in an aw4 at the same time we pulled the wire harness out of an 88 so everything was plug and play im not sure on the fuel pump curcuit but when ever the pump doesnt work all the gages dont work none of my head lights or signals work when it does run when you back up it cuts out and all the light go out
DaveB
Long Jeep Fan
- Location
- Holladay, Utah
Sounds like you are losing power for multiple circuits when it dies. I would check the main power connection terminals right behind the battery under the plastic cover. A good voltmeter test should tell you what is going on.
DaveB
Long Jeep Fan
- Location
- Holladay, Utah
On my son's 87 there is a plastic cover that goes over the electrical connection area on the wheel well behind the battery. Alot of the circuits get power from that area. Did you make sure all of the grounds were hooked up ?
UNSTUCK
But stuck more often.
You left a ground wire off somewhere. Likely on the firewall where you removed it from the old harness and forgot to put the new harness back on. It could be that once you hit reverse, the backup lights are the final straw as far as load goes. There is now to much amperage to get through the gounds that are still conected. Everything dies, then. Remove the loads and it fires back up.
i left the grounds off and thats when the coil went out i changed the coil yesterday after noon and hooked all the grounds up today my brother moved it first time he started it ran like crap when he went out later to pull it back in it started right up idle was perfect so he backed it up to see if it would cut out and it didnt had good power forward and back no lights flickerd and everything worked if it was a ground i dont think that would happen