ECU power when wire jumped in relay, but only when ignition is off? DOHC Swap.

[M374llic4]

I searched but was unable to find anything close.Car is an 89 with a 91 DOHC Swapped in. Also looks like maybe the car had an alarm in it at one point but then was pulled out and the part from the side opposite the key on the ignition where it plugs in to the next plug is put back together with tape and such, as well as the horn line was put back together. Ignition seems to work though. Car turns over.

I get no power to the ecu, atleast no lights unless I pull the relay off and jump the 2 wires closest to the fender, the 2 that are closer together.
Once I jump those wires I get light on my ecu, but only when the ignition is off. If i turn the key to on, it turns the light off.


Car turns over but will not fire up.



Anyone have any suggestions?

[datboibrad]

well when you jump them like that it doesnt matter if the ign is hot or not. relays have a minum of four things.

30-battery
87-thing your powering aka ecu
86-ground
85-ignition signal

the way relays work is the relay is always grounded. you throw ignition signal to terminal 85. upon getting power it completes the circuit and connects 30 to 87.

since 30 is always hot all you did was bypass the relay right to 87 this giving ecu power.

at this point either the relay is bad or your not getting a signal to pin 85.

[M374llic4]

thats weird then, why would I lose power to the ecu when its jumped then if the ignition is on? It is not making sense at all, I tried pulling the harness out, everything looked fine, made sure all the wires on the ignition were right, look to be. Shits got me scratching my head.

85 must be getting some kinda signal though? because when the ignition is off, ecu turns on?