wiring question for my 84 to 87 conversion

[matt87gn]

I'm just starting to get things laid out and ready to put the 87 harness in and realized that there are 3 extra pins in this harness compared to the 84. I figured they are for the fan and powermaster. NOW, has anyone done this conversion and know how to route these wires into the fuse panel without creating chaos??

 

[Instro84]

The engine harness should just plug right into the bulkhead connector. My 85 had the powermaster connectors on it so i didnt have anything i hadnt seen before. The difficult part was getting the ecm wiring thru on the right side, i removed the fender and it was easier. hth

 

[matt87gn]

This is on an 84 with the hydroboost brakes. (Actually thinking about keeping them now) What did you do for the fan?

 

[84TXGN]

The bulkhead connector will plug right in. The only thing you have to do is get a 12volts(key-on) to a brown wire that powers the fan relays(this wire also powers the powermaster unit so those with that already might not have had to do this). I did this less than 6 months ago and that was the only wiring I had to do. I found that the ECM side of the harness can be snaked down and into place without removing the fender. Just feed a coat hanger up through the hole and into the engine compartment, attach the harness(it helps to use electrical tape and tape all of the connectors together and into a safe position, have one person feed the wires down and the other in the car guiding then into the hole. The whole process took maybe 20 minutes. It takes longer than that to remove the fender.

 

[matt87gn]

thanks for verifying that for me. I was leaning towards hardwiring that brown wire.

 

[krebbie]

keep hydroboost

Just thought I would let you know I converted and kept the hydroboost, and it is awesome. I used the 87 power steering pump, to keep serpentine setup hassle free. I added the overflow tank from an 87, and had to buy a new high pressure line from the master cylinder to the 87 pump. Then custom make the low pressure return! In the process I tried vaccum brakes, and there is no comparison!! It will hold almost 12lbs at launch. I also bought the s shaped 87 line that goes from the gearbox to the pump. My $.o2 do it.

 

[84TXGN]

Just thought I would let you know I converted and kept the hydroboost, and it is awesome. I used the 87 power steering pump, to keep serpentine setup hassle free. I added the overflow tank from an 87, and had to buy a new high pressure line from the master cylinder to the 87 pump. Then custom make the low pressure return! In the process I tried vaccum brakes, and there is no comparison!! It will hold almost 12lbs at launch. I also bought the s shaped 87 line that goes from the gearbox to the pump. My $.o2 do it.

If you plan to go to open track days/autocrosses or something lihe that I don;t recommend trying to use the intercooled power steering pump with hydroboost. Those kinds of events put the pump under a lot of stress and I don't think the intercooled pump is big enough to handle it. Most guys don;t drive there Buicks like this though. Maybe it's a generational thing.

 

[matt87gn]

Yeah, I will keep the hydroboost. I don't do any courses etc. so it should work fine.

 

[conn84gn]

I just Finished my 84 to 87 conversion and kept the hydroboost. I have pics of the hose setup if you need them.
The only addition wiring I had to do was the jumper wire (jumper from the pink/black wire to the brown wire) for the fan and it worked great I can again run through this with you. real simple got info from Casper's great guy's on wiring

 

[conn84gn]

Looking at the connector on the firewall below the brakes.
You want the upper left pink/black wire that's pwr for ecm/sol to wastegate,EGR & can connect that to the brown wire going into one of the smaller selnoid switches for the fan

 

[TR Custom Parts]

Hey Brian, figured you would jump on this thread! :biggrin: So have you driven it yet???

 

[conn84gn]

No it's throwing a Code 42
So I have to sort it out wasn't the 37 injectors
the 42.5's are on now, got to check connections etc
might put the 109 chip in instead of the 8 postion setup

 

[matt87gn]

Looking at the connector on the firewall below the brakes.
You want the upper left pink/black wire that's pwr for ecm/sol to wastegate,EGR & can connect that to the brown wire going into one of the smaller selnoid switches for the fan

I kept the connector of the 86 I parted and only 3 wires were different being the brown, tan white stripe, and orange. I was figuring the tan and orange had to do with the powermaster and the brown was electric fan. Is this wrong?

 

[conn84gn]

First did you keep the complete 87 engine harness?

 

[Squid4life]

Are you guys saying that if converting from 85 to 87 setup, using the stock 87 harness, you will have to hard-wire your stock 87 fan? I fired mine today for the first time, fan came on by itself, etc. I never wired anything... Are you hard-wiring so they come n at a different time/earlier temp, or for some other reason?

 

[matt87gn]

yes, i kept the harness actually from an 86 ttype.

 

[84TXGN]

Are you guys saying that if converting from 85 to 87 setup, using the stock 87 harness, you will have to hard-wire your stock 87 fan? I fired mine today for the first time, fan came on by itself, etc. I never wired anything... Are you hard-wiring so they come n at a different time/earlier temp, or for some other reason?

Did your car have a powermaster on it? If so, that's why you never wired anything. The brown wire feeds 12 volts to the fan relays and the powermaster.

 

[Squid4life]

Yep, already had powermaster. Thanks for the clarification! Thought something was wrong with my stuff!!!

 

[conn84gn]

I am using the Hydroboost so that's why I had to do the jumper wire.
Powermaster wires are not connected.

 

[precizion818]

Powermaster Conections

I hate to bring up and old post, but is this a powermaster connection? I have and 1985 Buick Regal T-TYpe hotair. These connections are taped back, but in the area by the brake master cylinder. There are hydroboost on the car currently that I plan to keep. I keep hearing nothing but good things about the hydro! Someone please help me Identify these connections!!! This is before I swap out the wiring harness to the 1987 harness. Let me know if anyone recognizes these connections. Thanks in advance.
Sorry if the pic is Big!