Help! Fuel pump primes with headlights...

I'm a new guy looking for a little help.

I finally shipped my Cougar out here to me in Vegas and have been working on cleaning it up and finishing up some little things. A little bit of background on the car... The car is an 86 Cougar that originally had a 5.0/AOD. I bought a wrecked 86 XR7 and swapped over the 2.3T engine and C3 tranny. All of the car's original wiring was removed and all of the XR7's wiring was used for the swap. The car was running fine up until today...

I turned on the marker lights and noticed a few bulbs were burned out. I pulled the cluster out and replaced them but when I turned the lights back on, the lights did not come on and the fuel pump came on. If I crank the car the dash lights come on when cranking, but when not cranking the High beam indicator and both turn signal indicators light up. No other changes were made, only light bulbs changed. I pulled the cluster back out and the fuel pump stopped priming with the headlight switch, but plugging it back in caused the same effect again. I pulled the dash out thinking maybe a wire was pinched but had the same results. Then the pump started to prime even without the cluster connected, so I am stumped. I applied 12v to the various pins in the cluster plug and pin #1 and pin #16 made the pump prime. Now according to the pinouts on Coolcats, pin 1 is for "Brake, turbo, tach & speedo 12V+" and pin 16 is for "Tach in."

I would really like to get this stuff sorted out because I did the engine swap 3 years ago and have never driven the car. Thanks in advance!

Ed

I'd take a look at your igniton switch

When you turn the key your fuel pump and computer should turn on at the same time, the computer will let the fuel pump for a few secs to lube the injectors then turn it off till you start the engine. The computer will then kick back on the pump to run normally.

Though thats alot of problems at one time, everything you said connects to the ignition switch at some point and they are known for going out and cousing strange things to happen.

I am betting on a ground problem. Where, who knows. Since it started after you pulled the cluster, I would pull it again and make sure you didnt dislodge any grounds and that the cluster connectors are all clean and tight. Missing grounds can cause some seriously weird problems.

The ignition switch was replaced not too long ago with a spare I had. I will go buy one and see if it helps any. Flipping the lights on does the same as turning the key to run with regards to the fuel pump. It primes for a couple of seconds and then shuts off.

I thought it might be a ground too. Hopefully with the dash out I will be able to see more.

Thanks for the responses guys, I will report what I find.

The new ignition switch did not solve the problem, although it does eliminate the possibility.

Jeff was right on. It was the ground that bolts to the dash. I hadn't hooked it up when I swapped the engine and wiring in but it must have just been touching the frame of the dash making ground until I pulled on the wires to get the cluster out.