carb swap!

[maroman88]

and for my next question.....

how should i go about wiring up the dual electric fans

[BonzoHansen]

Search the electrical forum, there are a bunch of diagrams....are your current fans wired as per the factory? If so, is that ecm driven or switch driven?

[maroman88]

yea the ECM tells the TPI fans wat to do. i removed the tpi harness from the car but left the fan relay and harness for now until i figure out wat im guna do. i bought a TBI harness to hack apart and use but they only had single fans and i dont remember if the ECM controls it on a TBI car or not

[BonzoHansen]

Good. You just need to use the wires that ran from the ECM to the relay for the trigger circuit(s).

Simplest way: Get a fan switch, put it in the side of the RH head, connect the lead from the new f/s to the ECM wires at the relays - the 1 wire will splice to both --> "Y". I believe you should still have power at the relay (trigger & feed). If the trigger hots were cut then you'll have to run IGN power to them.

You could also run each fan on different switches for a lower & higher temp setup. Best is add a 3rd realy and run both at 6 volts from a lower temp switch and both at 12v off a higher temp switch. How complicated do you want to get?

Do you have AC? Do you want a manual override switch?

What car/year/engine are the 2 harnesses (TBI & TPI) you have from? I will look it up & draw a pic for you by Sunday night.

Cut as little from the ECM harness as possible (resale value)!

[maroman88]

the fan harness is from an 87 GTA and the new tbi harness is from an 88 camaro, i have AC

[BonzoHansen]

You have 2 fans?

[maroman88]

yes sir

[BonzoHansen]

So there are 2 fan relays? The 87 TPI diagram I have only shows 1 fan

See if this is what you have....

[maroman88]

hmm ill have to check on the relays.... there are 2 fans, one main and one when the AC is in use

[IROCdan330]

There are 2 fan relays. one is on the side of the rad support...one is up under where the passenger headlight is...

one fan runs off of the ECM telling it to...the other runs off the swtich in the passenger head.

been a little bit since i last messed with it, but i believe if you ground each of the relays to chassis ground, then put a switch in line...they should both work with key on power. the one that runs off the pass. head switch definitely is like that, and im almost positive the ECM only ground the primary fan relay, so it should also work like that.

[BonzoHansen]

Given all the changes to the car I don't want to assume what is actually there. He says 87 TPI harness, but the diagram I have for that is 1 fan. Same for 88 TBI. But my diagrams could be wrong too.

In either case, I think he can just use the dk grn/wht lead from the ECM (yes, the ecm supplies ground, as do the fan switches), but run it to a fan switch. the 2 fan setup appears to have a fan switch in the head - you could use that lead and both fans come one at once, or get a cooler temp switch, install it elsewhere, say the t-stat housing, then that one will come on sooner.

[maroman88]

one relay attached to the fan harness, but there was another one mounted in the same area but that was attached to the engine harness.... and this is in the radiator, and was used with my old TBI harness but not the tpi harness, im thinking either a low coolant sensor orrr a fan switch?

[IROCdan330]

or something to do with trans temp.

[BonzoHansen]

Originally Posted by maroman88

one relay attached to the fan harness, but there was another one mounted in the same area but that was attached to the engine harness.... and this is in the radiator, and was used with my old TBI harness but not the tpi harness, im thinking either a low coolant sensor orrr a fan switch?

I don't think it is a fan switch (never saw a gm one like that) or low coolant switch (seems too low). I dunno - I can't find it in any diagram (is that rad original to your car?).

See if the fan harnesses you have matches one of the diagrams.

[maroman88]

yea that sensor was plugged in on my old 88 TBI harness, when the new TBI harness comes ill have ti see if it plugs in

im guna say it looks closest to the first diagram u posted, but with only one relay on the harness itself... wierd

[Tru2Chevy]

That looks like the coolant level sensor that was on my '91 Lumina, but it does seem kinda low in the radiator.

- Justin

[maroman88]

Originally Posted by WildBillyT

You need a 3/8" NPT pipe nipple.

Like so:

http://www.hrpworld.com/index.cfm?fo...action=product

great..... so i bought 2 of these for the inlet and return from the regulator, only to discover that the return TPI hose is one size smaller (1/4in i guess). so now i need a 3/8in NPT to 1/4in NPT double male, and i cant find one, hell a 3/8in female to 1/4in male would make me happy lol why cant anything be easy???


EDIT...how about if i cut the ends off the stock lines and use these...


will it hold up to the pressure with some sealant and a hose clamp? mainly need it for the return

EDIT#2...got the carb and the wiring harness today... been one of those weeks, the electric choke was smashed to pieces in shipping

[maroman88]

installed the new distributor. need to wire it up. my engine harness has a thick red and white wire on one plug (that used to go to the coil) and the other plug is purple/white, tan, black and brown?(used to go to the old distributor). comming out of the new distributor is a red, black and brown wire....

what do i do?

[Tru2Chevy]

http://www.njfboa.org/forums/showthread.php?t=32858

Use the wiring diagram here to confirm what wires are what.

I rewired mine a few years ago and don't remember.

- Justin

[maroman88]

k cool

guna be black/red purple/white white tan/black on one
pink and white on the other

[maroman88]

on an update... still need help with how to wire up the distributor

[BonzoHansen]

A standard HEI dizzy is 2 wires - IGN hot (IIRC pink) and tach lead (brown).

My guess is the wires you need are already there.

And your cap is likely facing the wrong way to get to the wires. Although I guess it matters not as long as you put the plug wires on right.

[Tru2Chevy]

I'll try to remember to get a picture of mine tomorrow morning for ya....

- Justin

[maroman88]

bonzo.... i have those 2 plus a brown wire coming out of the dist, the cap itself has no wires coming out of and it i made sure the spark plug wires are correct

justin... thatd be fantastic!

[BonzoHansen]

There should be a small harness that comes out of the dizzy and plugs into the cap - you have that?