First time swap started

[ls1nova71]

I'm not sure why the speedo wouldn't work if the needle was returning to zero when powered up, unless you aren't getting a speed signal to it for some reason. However, I would be more concerned with how accurate it is going to be. The sweep of the two are different enough it may cause it to be inaccurate. If you take the S10 speedometer and draw an imaginary line from zero through the center of where the needle mounts, you will see that the other side will land at roughly the 83ish MPH mark, where as if you do the same thing on your original speedo you are going to be somewhere around the 65MPH mark. That's a pretty big difference.

[TrybalRage]

Originally Posted by ls1nova71

I'm not sure why the speedo wouldn't work if the needle was returning to zero when powered up, unless you aren't getting a speed signal to it for some reason. However, I would be more concerned with how accurate it is going to be. The sweep of the two are different enough it may cause it to be inaccurate. If you take the S10 speedometer and draw an imaginary line from zero through the center of where the needle mounts, you will see that the other side will land at roughly the 83ish MPH mark, where as if you do the same thing on your original speedo you are going to be somewhere around the 65MPH mark. That's a pretty big difference.

I had already figured that it would be off, but hoped that some pcm adjustments could address it. First I have to get the needle to move at all.

[ls1nova71]

You will be able to adjust the tune to compensate for the needle being off, but then the odometer won't be right.

But anyway, did you have the speedo powered up when you put the needle on? If you didn't then the needle may be way off and not able to re-enter it self. If you did, then its probably not the issue. Did you notice if the odometer worked while you drove it? If it didn't, then you most likely aren't getting a speed signal to it since you say the needle moved once when you powered it up.

[TrybalRage]

Originally Posted by ls1nova71

You will be able to adjust the tune to compensate for the needle being off, but then the odometer won't be right.

But anyway, did you have the speedo powered up when you put the needle on? If you didn't then the needle may be way off and not able to re-enter it self. If you did, then its probably not the issue. Did you notice if the odometer worked while you drove it? If it didn't, then you most likely aren't getting a speed signal to it since you say the needle moved once when you powered it up.

When I first tested the cluster, it appeared that the needle would reset to 0 when power was applied... or at least I reset the needle to 0 - but yes, it would move. I did not notice it yesterday, so I'll need to check it.

The odometer was not moving at all either, so something's totally off.

So first, I need to verify that the board is getting power. Then from what I understand I can hook up a multimeter to the signal wire & ground, and should be able to get some kind of measured voltage to at least verify that some kind of signal is coming from the PCM.

[TrybalRage]

Ah, the joys of projects.

Radiator cap leaking slightly at full temp. Go to store and get replacement ('safety release' style was all they had). Doesn't even get up to temp before it starts leaking through the 'safety valve'.

New AC Delco cap coming today.

Voltage low - 11.xx at battery, 11.xx at alternator. PCM wire to alternator showing ~5+ volts, so on my year motor I believe that's correct (some years it's 10-12?). So have to pick up an alternator.

I can get a new AC delco from amazon (105 amp) for $125, or a new 130 amp carquest from Advance for the same price, plus a 25% coupon. But I'd need a new belt, to replace my... new belt. Don't know if the extra amps are justified.

Still haven't gotten around to looking at my gauges issue. Maybe this weekend.

[jjzepplin]

Hang in there. It's all the little stuff that makes it worth it. I always have my alt. tested before installation.

[TrybalRage]

Originally Posted by jjzepplin

Hang in there. It's all the little stuff that makes it worth it. I always have my alt. tested before installation.

I'm just trying to figure out if I actually need one, or if the PCM isn't giving the right signal, or if I need something else.

I see folks talking about adding a light/resistor but that seems to be only carb swaps.. I think.

[jjzepplin]

I think you are right on that light stuff. I had to put a resistor on my older serpentine system swap to make the alt work. I would still have it tested. Heck, I have the new ones tested before I leave with it. Better than chasing wires and PCM issues.

[TrybalRage]

New AC Delco radiator cap and new alternator and we're back in business.

Still not sure what's up with my gauges. Temp sender wire is sending positive voltage that slowly drops as the engine warms up, so that seems normal.

Speedo is getting +10v at idle at the sender wire. I can jump a ground and sort of 'scrape' the sender connector on the board and get the needle to jump - the faster I scrape, the more the needle moves up. So it appears that with some kind of signal the needle will move. But it doesn't move when I'm driving. I'll need to jack up the wheels and put it in gear and see if/how the signal changes.

Could it be that the PCM isn't putting out the right kind of signal for this board?

[TrybalRage]

Took some time yesterday to try and figure out the speedo. Pulled the cluster, looked things over, tried to read a signal from the PCM with the wheels off the ground. Yes, it's getting something, no, I can't see the details with a simple multimeter. Apparently if you have an older-style needle sweep meter, you can see the pulses, but not with my digital one.

With a bluetooth dongle in the OBD port, and an app on my iPad, the PCM is registering speed, so the sender from the transmission seems fine.

I throw my hands up and figure bad board or I screwed something up and walk away from the cluster.

Took the rest of the day to replace the front brake hoses since my truck has been pulling slightly to one side since the beginning of the year. Should have done that while the motor was out... lord.

So I put the cluster back together, put it in so at least I can see my fuel level, and take the truck for a spin to test the brakes out.

Speedometer works. What. The. Heck.

Drove it around the block, came back and pulled into my driveway, there's a slight bump there - thump - needle drops to 0. Doh. Ok, gotta figure out a loose connection now.

But hey! It works. Worked. For a little. I count that as a win.

Then I parked and the lower radiator hose clamp which apparently wasn't quite tight enough decided to barf all over the driveway. Of course it did. One of these days I'm going to get this thing housebroken.

[jjzepplin]

Well that is better news about the speedo. I have to admit, I giggled just a little over the radiator hose. I will let you know about my bad karma for that when it happens.

[TrybalRage]

Originally Posted by jjzepplin

Well that is better news about the speedo. I have to admit, I giggled just a little over the radiator hose. I will let you know about my bad karma for that when it happens.

I get it, I just had to roll my eyes over it. Of COURSE you sprayed coolant again.

I think with the old (bad) radiator cap the system wasn't building to full pressure, and with the new one it finally got high enough to blow coolant past the clamp/neck and all over.

It's especially annoying since I've had leaking coolant issues from the get go.

Thermostat housing to pump - check.
Replaced thermostat that has new seal - still leaked.
Added coolant safe sealant to housing - ghetto fixed. (apparently there's a newer design to the pump/housing but we'll do that someday)

Reducer fitting for the steam line to radiator - leaked.

Cap - leaked.

Now bottom hose - leak.

[ls1nova71]

Definitely sounds like you have a bad connection in the speedometer somewhere. How did you attach the power, ground and speed signal wires to the circuit board of the speedometer?

[TrybalRage]

Originally Posted by ls1nova71

Definitely sounds like you have a bad connection in the speedometer somewhere. How did you attach the power, ground and speed signal wires to the circuit board of the speedometer?

The original flexible circuit board had little square metal tangs in it, I popped them out and soldered the wires to those tangs, then pressed them on to the pins on the back of the board. Works for every other gauge, maybe they're just not a solid enough connection for the speedo signal.

I was thinking of just soldering them right to the pins to secure them.

[TrybalRage]

Alright - update.

Took the silverado for a spin yesterday and she didn't pee all over the driveway when we got home (yay!)

The speedo was NOT working at first, but I've narrowed down the issue to a molex connector I added at the firewall to make the engine harness detachable from the passenger compartment. Either I didn't crimp it right or something cause if I sort of kick at the wires the speedo comes back on. So just need to add a better connection there.

On another note, love the power this thing has. Totally different truck. I think the shift points could use some tuning for harder acceleration, but at cruise speeds it's wonderful.

[jjzepplin]

Getting there! Woohoo!

[StingRay]

Consider that there is torque management in the system. It really dampens the shifts. It's also why the transmissions last way longer than the non computer controlled versions did. There's no free lunch. If you take out torque management you will give up trans life. If you do a performance rebuild then torque management can be pulled without loss of reliability. You also need to consider that when torque management is removed you may need to tune the spark curve for knock. When it shifts harder it could knock and pull a bunch of timing back causing it to fall flat on its face.

Originally Posted by TrybalRage

Alright - update.

Took the silverado for a spin yesterday and she didn't pee all over the driveway when we got home (yay!)

The speedo was NOT working at first, but I've narrowed down the issue to a molex connector I added at the firewall to make the engine harness detachable from the passenger compartment. Either I didn't crimp it right or something cause if I sort of kick at the wires the speedo comes back on. So just need to add a better connection there.

On another note, love the power this thing has. Totally different truck. I think the shift points could use some tuning for harder acceleration, but at cruise speeds it's wonderful.

[TrybalRage]

Originally Posted by StingRay

Consider that there is torque management in the system. It really dampens the shifts. It's also why the transmissions last way longer than the non computer controlled versions did. There's no free lunch. If you take out torque management you will give up trans life. If you do a performance rebuild then torque management can be pulled without loss of reliability. You also need to consider that when torque management is removed you may need to tune the spark curve for knock. When it shifts harder it could knock and pull a bunch of timing back causing it to fall flat on its face.

I've read about the torque management, I think I'd like to leave it in place. While I couldn't help some harder pulls for the grins of it, the real-world purpose of this truck is to do truck stuff. Towing my boat, hauling stuff, etc.

Since 99% of the time will be low-intensity driving, I'd like that protection for the trans.

[LS short box]

As I understand you don't need to take out all of the torque management out. Per the tune it can be adjusted to leave certain percentage in.
If you still have the stock tune in the ecm the trans will up shift sooner because GM wants the vehicle to go up into a higher gear as soon as possible for better gas mileage. A tuner can adjust the shift points to what ever makes you happy. Because there are bunch of 40 mph streets I use quite often I have the tuner delay the lock up of the torque converter until 45 mph. Helps prevent lugging the engine. All the tuner needs is your tire diameter, trans type and gear ratio to do the calculation.

[TrybalRage]

So I made a dorky little overview video talking about my swap. Skip ahead to about 4:20 or so to hear the exhaust.

https://youtu.be/sdrgC7R4Tds

[TrybalRage]

Been a while since my swap, still running pretty good but it's time to get the AC working before the summer heat kicks in.

Got the following coming:

- Denso 4710315 compressor for an 03 Silverado

- OSC 4953 Condenser for an 03; supposedly the original one would be fine but I sorta punched a hole in it by accident and a replacement is at least twice the price of an 03, so we'll make it fit.

- ACDelco 15-681 accumulator and 15-50120 orifice tube for an 85

- Four seasons 54275 evaporator core, figure everything else is new so why not.

I'll probably use Cold Hose for the hoses and fittings, they seem highly recommended. I'll need to figure out the wiring, I plan to run everything off the existing 85 controls if I can rather than PCM driven.

[notsolo]

Thanks for bringing this back to the top, You have some good photo's of where wiring is attached, very helpfull. I have the stock compressor in Stock location and need to figure out hose routing too.

[TrybalRage]

Originally Posted by notsolo

Thanks for bringing this back to the top, You have some good photo's of where wiring is attached, very helpfull. I have the stock compressor in Stock location and need to figure out hose routing too.

Once I get the compressor mounted I'll see if I need these for better routing.

https://coldhose.com/collections/gm-...pressor-blocks

[notsolo]

I looked, didn't see any A/C fittings like that on their site.....LMK..I would be interested....looking at your coolant bypass connection, found my Champion radiator CC 369 has a threaded inner core on the heater hose. I can thread a nipple in it and hook up the bypass hose. I step closer....Again photo's help alot.

[Davidf]

Originally Posted by TrybalRage

Been a while since my swap, still running pretty good but it's time to get the AC working before the summer heat kicks in.

Got the following coming:

- Denso 4710315 compressor for an 03 Silverado

- OSC 4953 Condenser for an 03; supposedly the original one would be fine but I sorta punched a hole in it by accident and a replacement is at least twice the price of an 03, so we'll make it fit.

- ACDelco 15-681 accumulator and 15-50120 orifice tube for an 85

- Four seasons 54275 evaporator core, figure everything else is new so why not.

I'll probably use Cold Hose for the hoses and fittings, they seem highly recommended. I'll need to figure out the wiring, I plan to run everything off the existing 85 controls if I can rather than PCM driven.

I think this is a good plan and one I will basically emulate with my build (2001 Vortec in 1971 C10). For me, Old Air products (50-7228) makes a conversion kit for my truck (wont do you much good on your 85). But, I may try and source the stuff separately...

As for controlling the a/c, I plan on going through the ECM/PCM. Main reason is that I want the PCM to control compressor clutch engagement so that it can set the idle speed properly to account for the added load. So, what that looks like is I will connect the +12v stock/original compressor clutch engagement wire to the "a/c request" wire of the PCM (pin #17). Thus, when you turn on the a/c, voltage will be apply to pin 17 which will cause the PCM to anticipate the upcoming load and send a control output via pin #43. This control output will activate a relay that will in turn engage the compressor clutch. I rerouted the a/c request wire from PCM (it originally went to the body module) to the wire harness branch that has the a/c LP switch and HO2S sensor (right side)...I will connect this wire to the factory compressor wire. The PCM pin 43 wire is routed to the added fuse/relay box to be connected to a new relay. All wiring will still go through the a/c LP and HP switch to protect the compressor and allow cycling of the compressor.

I figure I will (have) to use the compressor fittings as linked in above post and have to custom make many of the lines. I plan on putting the 2001 Tahoe condenser in front of the radiator (much of it will be blocked by the core support). I will also mount dual fans to the front of the condenser that will be activated via relay by the control output of pin #43 (so fans cycle with compressor). BTW, I am keeping the mechanical engine fan.

FWIW, I think if you do not allow the PCM to control the compressor, you will get a dip in the idle speed whenever the compressor clutch is activated. The PCM will notice the idle dip and attempt to compensate, but because the PCM has no way to anticipate the load, it cannot be ready to compensate so it takes a few seconds. Same going the other way around. When the clutch disengages and the load is removed, the idle speed increases until the PCM (via the IAC) can compensate. If you go through the PCM, the idle should stay more consistent regardless of compressor clutch activity. Also, I think some only connect the a/c request (pin 17) in parallel with the factor compressor wire. Result is vehicle switch is controlling the compressor and the PCM has a simultaneous indication that the compressor has been engaged. This smooths the idle somewhat, but not as good as when the PCM is allowed to engage the compressor.

Or so I believe.