Hey guys, got bit of a problem here. Went to take a spin around the block for the first time since I've swapped in my 5 speed (from a 700r4) and everything was going great at first. However, I noticed my speedo started acting up (electronic), jumping back and forth from 0 to my speed, then the SES light came on and started flashing, and the engine simultaneously started cutting out severely to the point it just died. While the engine was dying, I noticed the voltage gauge dropped very low, dash lights were dimming, etc.

The engine totally crapped out, electronics were still working, but when I went to restart it, everything just died before I even heard the starter click. No electrical whatsoever. Thought maybe I had a battery connection issue but it was very tight. Took the negative lead off and went to put it back on but it start sparking a lot when the contacts touched so something must have shorted out. I'm so stumped! The only wiring I played with for the swap was the clutch/neutral safety, reverse lights, and had to clip (but capped off) the automatic ECM shifter reference wires. Maybe the problem is totally unrelated to the swap?

The car is a 1991 Trans Am with a 305 TPI engine by the way.

 

I'm assuming that you used swapped the automatic starter for a manual tranny starter during the conversion ?? Even if you didn't; The first thing I'd check would be the power wire connections ( fusible links ) at the starter. They often look fine,... even when they fail.

 

Actually, later year thirdgens (starting in either 89 or 90) used the same starter for both manual and automatic cars, so fortunately I was able to keep my old one. HOWEVER I did have to unbolt it and move it out of the way when I installed the T5 bellhousing, so perhaps I knocked something loose while doing that. I posted my problem on a thirdgen facebook page as well and the general consensus was a short circuit at the starter. I'm going to try to look at it tomorrow.

 

Power wire at the starter. At least that's what I've seen in the past.

 

Gotcha, do you or anybody have a schematic by any chance?

 

On my home PC I have all of them. Go to austinthirdgen.com great site. That's how I make my obd2 harnesses. Lol

 

Found them, thanks!

 

No problem. Glad to help. Great site.

 

The sparking when reattaching the battery means something is drawing power. You may try pulling all of the fuses, then attach the battery and see if it still sparks. If so, you have a short somewhere on the ground side.
Then start putting fuses back in and see if/which ones spark... drawing power. Some, like the radio, ecm and interior lights will draw a small amount of power normally. Or, if you have a multi-meter, put it in current mode, check across the fuse contacts before putting the fuse in (the meter will flow and measure the current in place of the fuse) to see how much power each circuit is drawing. Then decide if that is normal or excessive.

 

check the wiring and fusible links at the starter and the battery cables.

my guesses are:

you have shorted wiring at the header / engine block.
or you pinched a wire between the bellhousing /engine block

Another place to check is the switched ignition power to the coil. (heavy gage pink or red wire)

I know this is a Tuned port Car but if switched ignition power to the coil is damaged and touching metal this will short out the whole ignition circuit & blow the fusible links at the starter. This happens on many TBI / Carbed cars when you change the stock air filter housing to open element because the new filter base is not recessed around the coil

A good way to check, is if the headlights still work this mean the short is on a switched ignition circuit.

 

Hey guys, got under the car yesterday and found the probably almost instantly. Very embarrassing lol but now the car works like nothing happened.



That starter wire must've gotten caught under the crank pulley as the engine was being tilted back into position when the new transmission was installed.

 

That's a good one. Always wondered how they ran the wire tho.

 

Don't sweat it dude,.... The only guy that's never made a mistake is the guy that doesn't do anything !


Zip Ties FTW !!!!!


The starter wires ran behind the engine, under the pass exhaust manifold ( thru a shield bolted to the bellhousing) and to the starter in many of the 'early' thirdgens. Sometime around 86 the power distribution/starter wires were run over the pass valve cover, down the front of the engine (behind alt. ) & then back to the starter.


Glad to hear you can finally begin to ENJOY the ride while ripping thru the manual gear-box !!

 

Thanks man! haha I can't wait to drive it either! I've been wanting to pull the trigger on this swap since I bought the car almost 5 years ago