just finishing my 4.9 swap and need help on a couple of wires
on the c500 where do I connect D3
on my c500 I have a wire in A1 and A2, everything I read either says there is one in A1 or A2 not in both, the one in A1 is black/white and the one in A2 is almost clear(I can see the wire inside). I know ones is ground
what do I do with the 2 purple/white wires that come off the E2 wire on the c500. the two purple/white wires got a connection on the end of them with a brown wire coming off of that

What year Fiero?

84 - 88 D3 - Coolant TEMP light - or if you have done the "Temp Gauge Pegging Fix" - the gauge. If still the light you can wire it to the 2nd coolant fan output of your ECM, and then have your ECM programmed with the temps you want the light to come on and off at, OR your 4.9 might have a temp switch located on one of the heads (it might be a temp gauge sender instead of a temp light sender so beware) OR you can use the temp light switch from the Fiero engine and screw it in somewhere on the head if it fits.

84 A1 - Dk Green - A/C from Relay to Clutch
85 A1 - Black - Power Trunk Release
88 A1 - 2.5 - Green wire runs to ECM

All years A2 - Ground. Yep kinda a light tan/clear insulation on your wire.

84 E2 -Dk. Blue - switched power from the fuse box for the back up lights
85-88 E2 - Manual Transmission - Purple - Runs to the starter solenoid - On your 4.9 it needs not to run anywhere else. If you had two wires a thick Purple/White and a thin Purple/White one ran to the starter and the other ran to the cold start injector switch.
85-88 E2 - Automatic Transmission - Not used.

[This message has been edited by phonedawgz (edited 02-16-2014).]

fiero is a 85 with a manual
was wondering about the pegging fix, mine needs to be fixed,so I wired it like I read in previous post but didn't use the d3 wire, could you tell me what wires go where for the peg fix so I can make sure I did it right

on my e2 the large purple wire has a connector on the end for the starter selonoid. also on the the conector is an orange wire that goes into the 2 purple/white wires. they look the same size,one goes to a conector that has a brown wire coming out of it( I assume the cold start injector you mentioned) and the other purple/white wire I had cut but not sure where it went ( I assume to the starter like you mentioned) do I just eliminate these two small purple/white wires
thanks for all your help,greatly appreciated

The orange wire is a fusible link to protect the small wiring from burning up if the cold start injector or the cold start injector switch heating circuit were to short out. Yep cut the orange fusible link right at the starter solenoid connector.

At C500 when wiring for the temp gauge fix wire as follows

C2 - Dk Green/Yellow - Coolant Temp Light
D3 - Dk Green - Coolant Temp Gauge

Here is the temp gauge fix. http://www.fierosails.com/tempgage.html Since you are doing the engine harness swap with the C500 wiring you only need to do the dash swap from this page. I was able to do the dash swap without cutting or splicing but I did have to cut back some tape/tyraps to get enough length.

Did you get your 4.9 ECM reprogrammed to eliminate the VATs yet?

[This message has been edited by phonedawgz (edited 02-17-2014).]

thanks for the info, yes had the ecm programmed to eliminate vats, what about the upshift light wire, wasn't to worried about it but couldn't, find a post on what to do with that wire
thanks again for the help

quote Originally posted by ozzman333: thanks for the info, yes had the ecm programmed to eliminate vats, what about the upshift light wire, wasn't to worried about it but couldn't, find a post on what to do with that wire thanks again for the help

C203 A -Tan/Black - Upshift Light - Not used on an automatic - 4.9 ECM does not support for MT.

[This message has been edited by phonedawgz (edited 02-19-2014).]

thanks again for the help,the two orange wires from caddy ecm,do they go to power distribution block or straight to the battery

I run them to the power dist post and then connect to it via an weatherproof fuse holder with a 10A fuse installed in it.

I also fuse the power wire to the distributor at 20A right next to C500

That wire might be Dk. Blue or Pink. It runs from E3 to the power connector on the distributor.

[This message has been edited by phonedawgz (edited 02-19-2014).]

I see a fusible link on e3 where it comes out of c500, should I still add the fuse

It's up to you. I like the idea of a fuse since it is easier to check and easier to replace. Maybe the best is to just keep the fusible link since it is already in place, and since it most likely will never fail.

how many engine grounds do you use

For the harness - two. I put them on two separate bolts on the drivers side of the front head.

The Black grounds - C203, C500, Oil Pressure sender grounds, Fuel Pump Relay and A/C Clutch on one lug.

The Black/White grounds, - ECM, O2 ground (Tan) if one wire O2 sensor, ISC, and injector grounds (Tan/White) on the second.

These do not include the body to engine straps. (At least two are recommended) I also recommend the battery cable be connected directly to the engine. Don't try to get away with putting the battery up front and using the frame as the negative battery cable.

[This message has been edited by phonedawgz (edited 02-19-2014).]

can you tell me where c203 pin h goes to

Unused with the 4.9 swap. The VSS (Vehicle Speed Sensor) used to start at the transmission, run to the speedo, and then was back fed to the ECM via the brown wire on C203 H.

The 4.9 ECM can read the VSS directly. No need to backfeed the signal from the speedo to the ECM.

With the 4.9 MT swap you should run the VSS from the transmission to the ECM and then also to the speedo. If the speedo doesn't work swap the two wires on the ECM.

4.9 AT you run the VSS signal to the ECM and then use the ECM 4000 PPM speedo output, sent through a buffer circuit to run the speedo. Just like the 4.9 MT, the 4.9 AT does not need to back feed the VSS signal from the speedo to the ECM.

If you need the buffer circuit you can purchase it pre-made at my website - http://reddevilriver.com

I have a manual transmission, so does that mean I don't use the buffer circuit

Run the yellow and purple wires from the VSS to near the ECM. Then have the yellow and purple wires that run to the ECM VSS input. Finally have the yellow and purple wires that run to C203. Now solder together and insulate the three yellow wires. Then solder together and insulate the three purple wires.

Think of a T. One leg to the ECM. One leg to the VSS. One to C203.

That is all that is needed. No speedo buffer needed with the MT swap.

[This message has been edited by phonedawgz (edited 02-20-2014).]

is the buffer the same as the 12 volt bias circuit,i was told I need the 12 volt bias to run the speedo

I've never heard it calles a bias circuit. It's not needed with the MT.

thanks again for all the help, greatly appreciated