wiring questions

[turbox4]

I finally have the engine in my 84 Ttype but would appreciate help with some wiring issues. I need to know where the gray connector coming out from under the coil with a black wire and red wire goes (see link below for picture).
http://members.ispwest.com/gtut/wirebycoil1.jpg
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Also, the crank sensor connector from the coil is spliced in and has different color wires than the rest so it is not stock and I suspect a wiring problem. I would appreciate info on which of the three wires coming from the crank sensor connect to which color wires going into the coil. The crank sensor wires are red, green and black. The wires into the coil are a small black next to and left of the coil connector screw and a green and a larger black to the right of the connector screw.
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Finally, does the coil have an external ground besides the connector? Thanks for any info.

 

[kh440]

Pic looks like the regulator plug for the alternator. Ring termonal goes to the stud on back (where the wire from the batt cable). Don't know what to say on the crank sensor wiring other than if it starts it's right. Coil does not have any other ground, can try to take some pics of the wiring from my 85 if that would help.

 

[turbox4]

Appreciate reply. It does look like an alternator wire but the alternator is on the other side of the engine and a similar wiring setup is already hooked up there. Could it be for an option or maybe the harness was for more than one car, possibly with the alternator on the left side?
The car does fire but seems to want to almost backfire. I now find I have another issue. I only have fuel pressure during the start position. In run it shuts down. My other TR's have constant pressure in the run position so I will have to chase down the problem.
Pictures of the crank wiring would be most helpful. Just a picture of the connector showing wire colors going in and coming out would be great if possible. Thanks.

 

[kh440]

Just for the sake of asking was the harness changed at any point? I've never seen more than one alt lead in the same harness. I'll try to get you som epics in the next day or two. Hard to answer on the near-backfire, again to play devils advocate a is the can sensor timed correctly and are the plug wires on right? (easy to get them confused-don't ask how I know)

 

[Buick From Hell]

go up to the "BASIC HOTAIR INFO" thread at the top of the page, then click on the "ignition module wiring diagram"link...it's a diagram that shows the all the correct wire colors, and exactly which wire goes where in the module. Even if the sensor wiring has been spliced, the wiring at the sensor itself HAS to be original, even if that's where it's been spliced! (should be at least a "stub" of the original color wiring)...

hope this helps!

 

[cool 84]

That's just weird. It's identical to the alternator plug. I've never seen that plug anywhere but the alternator. It just happens to have the right length wire coming off the plug with what looks like a factory crimp on the connector. Could it have been one of those cars made for stereo competitions that use two alternators?

The FP should come on for a couple seconds when you turn the key on and then come on again as soon as the computer sees ignition pulses. The oil pressure switch is kind of a backup that will also let the pump come on as soon as it sees oil pressure. You can run a positive wire to a single wire connector near the powersteering pump area (black, I believe but not sure, maybe tan), and it will supply power to the pump.

 

[HOTSIX]

Ya...like COOL84 said, that wire will supply power to the fuel pump.

Some guys use it to purge all the remaining 93 Octane gas when they are gonna use race fuel before a race.

To confirm - its a grey wire with a black connector on the end of it. Its a short wire that peeks out of the wire loom around the harness right between the inner fender and the power steering pump.

As for the pictured wire - its definitely an ALT connection - but you say the ALT is already hooked up ?????

The ALT has more then just the battery wire going to it...it has the IDENTICAL type wires you have pictured there. It plugs into the side of the ALT and the ring goes onto the back of the ALT on a terminal.

Be sure you have that all there.

 

[turbox4]

All great info and gives me some things to try. I don't know history of the harness but it may be from a different year. I verified the cam sensor setting and plug wire routing. I will hot wire the pump using that little plug and see what happens as soon as I'm sure I have the wiring right.
The spliced in plug goes to the three wires on the coil. I checked the "hot air" schematic but something is not right. The schematic shows the crank sensor as ACB top to bottom, my plug from the sensor is marked ABC. It's also the only one item on the schematic that doesn't show colors and the schematic shows A going to the white/red which is left of the screw. On mine the wire left of the screw is black and the one left of that is white/red and goes into the wiring harness. On mine the wire right of the screw is green and the next one over is black. On the schematic, the two are reversed. If I ignore the colors, my A goes to J, B goes to G and C goes to H which agrees with the positions
shown on the schematic. I will try that and ignore the colors. I hope to live long enough to someday find a schematic that actually looks the same as one of my cars.
I double checked the alternator and there is a two wire plug going into it by the air conditioner with a green and black wire and a single red wire from the battery going to the post on the back. There is no other place to plug in the other plug even if I could get it to reach which is doubtful. Maybe it will run without it and I will find out what isn't working. Due to another car crisis, I may not get to this for a day or two but will report back. Thanks again.

 

[kh440]

Am I understanding this correctly--that plug is hooked into the coil wires? That makes no sense, I would say cut it out, starting to wonder if that ties in with your no start problem--just for hoots and giggles trace as best you can and let us know where it goes-very curious about this!

 

[HOTSIX]

Wait a minute....

The green wire with the plug-in on the end could very well be your A/C compressor connection.

Mine is a green wire and has a plug-in like the ALT does.

Might have that plugged into the wrong spot.

 

[cool 84]

Originally posted by HOTSIX
Wait a minute....

The green wire with the plug-in on the end could very well be your A/C compressor connection.

Mine is a green wire and has a plug-in like the ALT does.

Might have that plugged into the wrong spot.

Exactly! I wonder what effect that would have on the ECM once the alt spins and makes some voltage? Maybe a sputter and then die lol.

Also, I forget which plugs can be mixed up but I've done it and had a no start. I believe it was the cam sensor and injector harness plug.

 

[turbox4]

All that makes sense. I routed the wire in question up from the main wiring harness behind the coil. It very likely goes the other direction to the alternator. The one I now have in the alternator is green and black which as pointed out, probably goes to the AC. If that cures my no start, I will be doing cartwheels. Hope to get to it tomorrow and let you know. Thanks again for all the help.

 

[HOTSIX]

I'm certain now that is your problem.

 

[turbox4]

Thanks to you guys, the crank sensor and alternator wiring are now correct. I had the AC plugged into the alternator as you suspected. I can't believe I did that. Anyway the bad news is I'm still getting a no start. It does the same thing. It fires and then stops short of a backfire but definitely sounds like a timing problem. So far have verified fuel pressure, plug and fuel injector harness routing, plugs are wet and spark at the plugs. Check engine soon light is on in the "switch on" position. Also verified cam sensor setting and it was right on. I have arranged to borrow a SnapOn computer from a shop for this weekend to check crank and cam sensor signal and hope that or something else will show up. Also, plan to check wiring harness with a tester to make sure all are firing and also try another computer. If cam sensor was 180 off, would it cause this problem? Any other suggestions appreciated.
Thanks again for getting me this far.

 

[kh440]

Very well could. Even with the setting tool it can take more than one attempt before it comes to life (found that one out the hard way)

 

[HOTSIX]

Ya...I had problems with my cam sensor too. After my rebuild it took me 3 sensors to get it right.

That cam sensor seems to be a tempermental item. Also you wanna check your crank sensor too...my crank sensor bracket was cracked and sensor bad so I replaced that too.

Gotta be something simple though...maybe try the scanner and see what codes come up. If you want - use a paperclip and jump the 2 ALDL terminals together to see if a code has been tripped.

Theres a procedure on this on gnttype.org I believe. Tells you what codes mean what too....

 

[turbox4]

I rechecked the cam sensor and verified no codes are present but I now find that the black wires on both the cam and crank sensor aren't grounded. I get a ground on both of these on my 86. Any ideas on what could cause this. Also, I have found that the cam sensor plug is spliced in with different colors as well as the crank sensor. A lot of the ICM wire colors don't agree with the colors shown in "Hot air info" or my factory manual and the "hot air chart" doesn't show colors for the crank so I can't pick out the right pin positions. I hate to ask this but could someone with an 84 tell me which colors on the crank and cam sensors go to which colors on the ICM or just tell me pin position and ignore all the colors. This might be better as the colors are old and hard to describe. I posted a picture of my ICM plug (link below). My crank sensor wires are top to bottom facing engine, green, red and black. My cam sensor wires from left to right looking down, are red, green and black. I still plan to use the scan tool this weekend but would like to start at least knowing the wiring is correct. I really appreciate your not giving up on me as I am almost ready to myself.

http://members.ispwest.com/gtut/icmplug1.jpg

 

[HOTSIX]

George - I converted mine over to an 87 module and coil from GM. Got the conversion plug from Caspers Electronics.

I'd say that someone has been messing with your wiring harness - to say the least. My harness just has plug-ins from the cam and crank sensors to plug into the harness.

Do you have plugs or did someone just 'splice' them into the harness wiring ?

 

[turbox4]

The cam and crank sensor wires coming out of the back of the ICM plug were all cut and different plugs with different color wires were spliced in. The plug on the crank sensor is also spliced in with different wire colors. I may convert to an 87 setup later but I want to get the wiring sorted out first. It may be o k but I really doubt it. Any idea on why there is no ground on the black wires coming from the cam and crank sensor?
Depending on my sucess with the scanner this weekend I may put this project on hold for a month. Dennis Kirban is hosting a conference at the Holiday Inn just north of Seattle on June 7th and I hope someone will be there with a semi stock 84 or 85 TR that will let me take some pictures as a baseline. Thanks.

 

[HOTSIX]

Let me make a suggestion:

Why not buy an 84-85 ICM plug wiring harness for your car from Caspers? My wiring was all fried when I bought my car and this item fixed it right up. You will get correctly coloured wires with a plug in for the Cam and Crank sensors.

Its not too expensive and will remove the guesswork from the project.

My guess on the sensors having no ground is that:

1. the wiring is messed up to the ICM therefore preventing them from getting the correct connection to GND.

2. Both sensors are cooked. I find this is unlikely but possible. Question is did you just buy the car or did you have it when it was in running condition ?

If you just bought it in non-running shape - like me - then i'd replace both sensors.

Might not need them replaced but with a new Casper's ICM harness and 2 new Cam and Crank sensors, you will eliminate the guesswork with the wiring. Its wayyyy too confusing to mess with the wires in my opinion. Trust me - I did it.

You can always keep them as spares if they turn out to still be good....(thats what I did with one of 'um)