Need Minimum wiring size to run to ECM

[MTTwister]

Ok, I've out-tricked/clevered myself. I'm Putting in a triple pillar gauge pod, and have 3 switches, one next to each gauge- top will shut off gauge lights if they're too bright at night. Then middle one ( next to the Pyro) will control the Hi- Lo idle. The lower one, next to the Tranny temp, will contol the cheap TCC lock-up if needed. Oh, and there's a hot in run wire to power the related LED's for the 2 lower switches. and a Ground.

Problem - I've over built, and used 16ga wiring. Needless to say the additional 7 wires aren't gonna fit behind the original pillar cover, along with the primary gauge connections and boost tube.
So, I need to replace all this with lighter, thinner wiring. 18ga doesn't seem that much of a volume reduction, for the labor involved. These can't be carrying much of a current, so What's the minimum size wire I can get by with? ? 22ga? - Do they make 20 gauge wires. Naturally I'll need @ 6 different colors to keep my wiring straight.

Input appreciated! Thanks .

[gmctd]

At your local boneyard you'll find many GM vehicles with ECM-PCM wiring harnesses.
Vans will have longest wire runs (length).

Take your choice, and snip away - wire gages will be correct size for your requirements, and colors will match GM circuits for power, ground, lighting, etc.

Works for me. :cool:

[MTTwister]

gmctd - Nice idea, but bone yard probably isn't gonna happen till it warms up. And they're probably scarce in our local yards, too.

I need lenghts to run from the driver's pillar across to the ECM on the passenger's side. I picked up some 20ga stuff, and hopefully that will reduce the volume enough to squeeze all this in.

Busted off the bottom clip on the a-pillar of course - nice design THERE, GM!

[gmctd]

Sorry - it's 70deg in the shade, down here! ;)

[Scooby]

MTT- I was wondering what you are going to the ECM for. I am currently also installing a triple gauge a pillar. How are you getting the hi/lo idle to work ?? Is that why you are going to the ecm ?? I was planning to run the boost tubing, egt harness, and trans temp wire directly to the pillar.

[moondoggie]

Good Day!

The following is for tin-coated copper wire (Ω = ohms):

AWG

[Craig M]

Hi MTTwister

Where did your get your 3 pod set up. I have tried the "normal" guys, and they all seem to only have the 2 pod set ups.

[MTTwister]

Craig M - I got 3 pod through Gomer's diesel when I order gauges with the gauges - but you should be able to get one via Kennedy, or ( non-sponsor: SummittRacing. ( web site dot com) All appear to be AutoMeter Pods.


Something else I did - removed the rubber mounting ring, and added One wrap of Black Electrical tape on the gauge body, adjacent to the face trim. Reinstalled the rubber trim ring. This seems to provide a really good Friction Fit, and you shouldn't need the gauge brackets. should be able to pull the gauge out to chaage bulbs without removing the pillar pod. In Theory....

Scooby re the extra wires -

The high - low idle switch is a DPDT - with one side wired to an LED ( on the otehr side of the pod holding the EGT.)
The Other side has 2 wires that will run to the ECM to the Brown 24 pin Connector ( it's in the middle). Pin pos B8 ( lo),and B7 (Hi) - purpose is to ground those for a low and high idle.
( The A, and B's refer to the Row positions in the Connector. The connectors are labeld C1, C2, C3 but also have colors and pin sizes described in the manual)


On the Lower pod with the tranny temp, it's a DPST has the 50 ohms across the 2 wires that will attach to the Trans TFT ( trans Temp - ). Search on "Cheap TCC Lockup" thread

per my '96 manual - the TFT sensor wire - yel/blk, circuit 1227 - goes to pin C9 ( middle top row) on the BROWN 32 pin connector -C1 at the PCM .( first big connector you see - or I see at the ECM)

The Black wire in the above Brown 24pin connector - B12 ( the black one on the end. ) is the other 1/2 of the TFT circuit to tie into. The other side of the switch also has an LED.

Kept LED power and Grounds separate form any other circuitry.

Moondoggie - thanks of the wiring info. I can't believe that these are carrying a heck of a lot of current. Most current would be for the gauge lighting circuit - 1- 3 watt bulb & 4- 1.4 w bulbs.

OK - Ripped 16ga and ran 20 ga last night. Need to retro the pre-wiring on my switches, then get the BFH to get this sucker in. I still have to do the Tranny flush,Boost Fooler ( it's ready to wire in), and get the axle leak fixed before May 1. (road trip)

Appreciate the Input, youse guys. Thanks!

[MTTwister]

Just an Update - Finally got the whole deal installed, yesterday. 1 pm - 10 pm. Rain, snow, rain, snow, cold.. whine-whine.
Yes, overbuilt, had to make sure all the wires could be pulled through with the stock A-Pillar back in place. Also, used to flat head screws to secure the lower clip back on the pillar pod, where the cheap-a$$ melted plastic GM operation had broken off. :mad:

Still need to make the final connections to the ECM. Maybe today, after my tranny flush / filter change.

Hopefully I'll remember to take a pic of the install. ( old age creeping-in - "Now why did I come out to the garage?" ) :rolleyes:

[a5150nut]

MTTwister,
Memory.........

Do You have AAADD? I thought it would help to know there are others out there.

YOU ARE NOT ALONE!!!!!

They have finally found a diagnosis for my condition. Hooray!! I have recently been diagnosed with AAADD! Age Activated Attention Deficit Disorder.


This is how it goes:
I decide to wash the car; I start toward the garage and notice the mail on the table. Ok, I'm going to wash the car. But first I'm going to go through the mail. I lay the car keys down on the desk, discard the junk mail and I notice the trashcan is full. Ok, I'll just put the bills on my desk and take the trashcan out, but since I'm going to be near the mailbox anyway, I'll pay these few bills first.Now, where is my checkbook? Oops, there's only one check left.


My extra checks are in my desk. Oh, there's the coke I was drinking. I'm going to look for those checks. But first I need to put my coke further away from the computer, oh maybe I'll pop it into the fridge to keep it cold for a while. I head towards the kitchen and my flowers catch my eye, they need some water.


I set the coke on the counter and uh oh! There are my glasses. I was looking for them all morning! I'd better put them away first. I fill a container with water and head for the flower pots - - Aaaaaagh! Someone left the TV remote in the kitchen. We'll never think to look in the kitchen tonight when we want to watch television so I'd better put it back in the family room where it belongs. I splash some water into the pots and onto the floor, I throw the remote onto a soft cushion on the sofa and I head back down the hall trying to figure out what it was I was going to do?


End of Day: The car isn't washed, the bills are unpaid, the coke is sitting on the kitchen counter, the flowers are half watered, the checkbook still only has one check in it and I can't seem to find my car keys! When I try to figure out how come nothing got done today, I'm baffled because I KNOW I WAS BUSY ALL DAY LONG!!! I realize this is a serious condition and I'll get help, BUT FIRST I think I'll check my e-mail.

[Scooby]

I got my triple pod in over the weekend too. I still have to remove the tranny pan to change/ flush fluid, and braze adapter in for temp probe. Pod and gauges are done though. My gages (autometer) fit the pod tight with no trouble. In fact, I had to remove the stickers on the side of the gage to get them in. I didnt remove the factory pillar either. The wires/tubing fit between the pillar trim and the dash with the help of a long screwdriver. I had the boost gage on top, and after a test drive, decided to move it to the bottom- it seemed to high to just glance at while driving. I put the trans temp up top- it will be the slowest changing anyway. Thanks for the wiring info !! I have the set of manuals, but havent had a chance to dig in yet.

Rick

[MTTwister]

Scooby -
There a 'Test Port' on the tranny - driver's side - just above the linkage that has the same thread size as the temp probe. A screw-in deal. Food for thought.

Another update - Sunday: Got the Tranny Flush, Filter and 2wd drainable pan done. Also installed the remote FSD on the Splash shiled - ( stinking Plastic!). The new FSD out of the box had 3 finger loose transisor screws, so I did the finger tight + 45

[gmctd]

Nice humor break, -nut. :D :D

Now, if I could just remember why it shouldn't be all that funny ... ;)

[MTTwister]

Damn, SCOOBY - you would have to bring that up -
"I had the boost gage on top, and after a test drive, decided to move it to the bottom- it seemed to high to just glance at while driving. I put the trans temp up top"

While driving around, now I'm wondering - how big a pain it would be to snake the Tranny temp wires up to the top. It's behind the original pillar. - hmmmm... Dang IT! I like your placement idea. oh boy!

[Scooby]

Sorry about the extra work MMT !! I had to lengthen the power wires to move the temp gage up top too. I had plenty of wire for the sending unit connection,(not hooked up at tranny yet!!) but not enough coming from the fuse panel where I tied in to the gauge fuse for power to the trans and egt gages. OF course the bulbs stayed where they were, so no issue there. Luckily I hadnt fastened the pod to the pillar with the plastic rivets yet, so I just laid it on the dash and changed the gages around.
Does the threaded port you are referring to have any flow by it?? Or just pressure to it ?? I wonder if it would give an accurate reading. Anyone tried that port ?? I have brazed fittings in before, but if that port works, I could have an operable gage in about 15 minutes.

[MTTwister]

Scooby - I had to lengthen my Trans temp sender wires to reach inside the cab.

My current belief is that the transmission Test Port is at minimum a 'constant' splash. However, there must be some pressure or flow, or what the Hay are the 'testing'?

I read about it on another thread, and that the 'guy' was getting a pretty good reading from it. However, I don't believe he was 'stressing' his transmission, just keeping an eye on it.
Somebody around here should have a definitive answer.

[HammerWerf]

Folks,

I to am installing the triple pod in my Suburban. My question is where did you penetrate the firewall. For my application, I will also be bringing the brake controller wires (Blue & Power). And how do you remove the lighting switch to get volts to the guage lights.

Scooby, it sounds like you did not remove the dash. Any tricks to help get the wires through???

Thanks.

HammerWerf

[tom.mcinerney]

5150 N~ : LOL...

MTT et al. : Moondoggie's illuminating effort suggests another option. Since the resistance is proportional to length, it's permissible to use a light gage pigtail thru the congested area, then splice into your heavy lines for the long run.

HammerWerf : Need 1) loosen dash , 2) remove sw.
see<http://www.installdr.com/InstallDocs/GM/PDF/460005.pdf> refer to <http://www.mnrelectronics.com/> .
Pull dash upper corners, R & L. Free L-sw tabs from behind(front) dash, push sw out to rear. May need remove other sw in center dash for access. It helps to have batt discon, & auto shift lever down .

[Scooby]

I didnt remove the dash or the original A-Pillar when installing my gage pod. There was already a hole in my firewall with a rubber grommet in it- the truck had previously had a brake controller installed. I used this hole to run the wires for my brake controller and for the gage wires/tubing. It is above the accelerator pedal.

I did not remove the headlight switch either. I removed the screw holding the fuse panel in place, and rotated it around enough to locate the wires going to the factory gauges, and the dash lights. I cant remember wire colors, but they were easy to locate by looking where the fuse is, then looking in that spot on back of the panel. The fuses are on a buss, so there is only one wire per fuse, thats the wire you need- on the load side of the fuse. It was difficult working in that dash, but I didnt want to mess with the headlight switch, and I wanted my gages to run on the GAUGES fuse, and the lights to dim with the dash lights. The fuse panel seemed the best place to tap in, without disturbing harnesses. I stripped some insulation off the wires, tinned the wires with a soldering iron, wrapped the new wire around, and soldered it. Then I wrapped the connection with electrical tape, and put a tie wrap around the tape to ensure it didnt "unwrap". I never actually cut the factory wire. It was a little tricky, but it go the results I wanted. Maybe someone else has a better place to tap in, but thats how I did it.

[MTTwister]

I also ran the wiring through the grommet that would be an accel cable if it wasn't drive by wire. And I have a bunch of wires in that hole. ( 3 10 ga hots' ( Stereo amp, fog lights, elect brake - fog light returns to the relays, and now the gauge related wires and tube. ) Actually have maxed out the grommet, and need to get some sort of protection on the mess going through that hole.

Gauge Illum - on the '96, theres a fuse panel on the driver's side of the dash - accessibel when the door's open. Fuse 14 is ILLUM - and the voltage varies with the dash light resistor. I used a Fuse 'leg' piggyback from Napa - it clips on the fuse leg and you can put a spade connector on the other end. Needed to shave it down, as these are mini gauges, and although the adapter was the smaller size, it still needed work.

I don't have Airbags so I used fuse slot 10 - hot in run on the same panel to power the boxes for the Pyro, tranny temp, LED's and the radar detector.

'99 may be diff, but look in there, if it exists, fuse usage was on the inside of the cover.

[Fredeberle]

5150nut,
You sound like a twin. smile.gif
Only forgot the aches and pains when you do get something finished! :rolleyes: