name this plug??

[emoo99]

i took out my ac, heater, blower motor.. and some stuff under the dash a few months ago.. i left all the loose wiring intact.. yesturday i took out all the harnesses and wiring for it.. now my speedo doesn't work and i don't know if the problem is related or if i yanked some other wire loose?? there was this one plug, that was also pluged into the harness that i disconnected.. this is a black plug, it was apart of the whole ac/heater harness assembely.. it has: A B C D terminals.. A- is empty B- has 2 brown wires with a white stripe C-has a solid green wire D- terminal is empty and the E- terminal has a solid brown wire, this brown wire was connected to a single wire going back behind my gauges.. was this for the speedo? i cannot find the other part of this plug(male side) but i believe it's under the dash somewhere still.. i ve searched a billion wiring schematics and seached ck5 all over.. but cannot find this plug.. i wanna put a voltmeter on the male side of this mysterious plug and see if it has 12v constant.. or so i can attach this brown wire i disconnected back to the male plug to see if myspeedo comes back on... any clues?

 

[lectric80]

Simple way to tell would be to slide underneath and take a look at the wiring on the VSS at the back of the transfer case. It wouldn't be unheard of for a plug to go to multiple things, like be tied into the A/C system and the speedo feed. The diagrams I have don't cover the newer stuff with electronic speedos so I can't give you wiring colors. That would just be the first place I would look, then you could even trace that wiring and see if there is something simple that got bumped.

 

[emoo99]

the only other thing this harness was plugged into was this plug... all the other wires were loose, and right after i disconnected it my speedo stopped. could be a fluke and i may have yanked something else.. i'll go

check the vss..

 

[pblaze725]

Go push the speedometer cable back in. You could have pulled it loose.

 

[lectric80]

Possibly something as simple as a ground wire, but it sounds like something just popped loose. You might try a PM to 4x4high since he just completed installing a guage set in his 89, and he might have some info on which wires are used in your setup. 89+ are all electronic speedo and should be very close in wire color, most likely identical.

 

[89GMCK5]

89's are mechanical, 90 went to VSS.

 

[sweetk30]

bet its the hearter blower motor switch . only thing i can think of .

and below the radio is a white box . thats your speedo buffer unit. is it still there and pluged in ?

 

[89GMCK5]

Wiring daigram

I am looking through my wiring diagram and it looks like a bulkhead connector for continuation of wires associated with the fuel control and idle air controls. Tan / white = fuel pump fused circuit 120. Drk grn / wht = fuel pump relay normally closed side of coil. Brown = air switch L05 engine only.

I'm going to continue to hunt through them though.

 

[89GMCK5]

SweetK30 you are the man!!! I should have known, experience always pays.

Naturally, I was way off.

That connector is for your selector controls:
BRN/WHT= blower switch
BRN/WHT= thru firewall to heater resistor
BRN= Hot in run position
LT GRN=Evaporator pressure control switch

Man the knowledge on this site is amazing, and off the top of his head....

 

[emoo99]

it's too late now.. but i'll strip the wire and turn the key and see if i get 12v from it.. if that's the case, i probably loosened some other wire on accident that's making my speedo not work now.. for an electric speedo it should zero out when keyed on right?, just like my other gauges? if i'm not getting any movement at the needle when keyed on acc/run, it more than likely has no power to it, to if i key power to it and start pushign on wires theoretically i should see it "zero out" when i hit the correct wire.. is that right?

 

[lectric80]

Yes it should zero out, and the wiring is all run through a large bulk connector at the back of the cluster.

 

[emoo99]

I am looking through my wiring diagram and it looks like a bulkhead connector for continuation of wires associated with the fuel control and idle air controls. Tan / white = fuel pump fused circuit 120. Drk grn / wht = fuel pump relay normally closed side of coil. Brown = air switch L05 engine only.

I'm going to continue to hunt through them though.

does the wiring diagram show where the drac draws the power from?, i wonder if it was tied into this harness that i pulled from the heater/blower/ac stuff.. and when i disconnected this brown wire (hot in run position) it then cut power to my drac/vss system?

 

[4X4HIGH]

does the wiring diagram show where the drac draws the power from?, i wonder if it was tied into this harness that i pulled from the heater/blower/ac stuff.. and when i disconnected this brown wire (hot in run position) it then cut power to my drac/vss system?

The DRAC just needs a keyed +12 volts, and a ground. Don't worry about the drawing on the right as your blazer doesn't have that since it was factory with a DRAC unit.

EIDT: The brown wire you have might be the one for the DRAC power as it comes from the HTR/AC fuse. Use a DVOM and check for continuity from that brown wire to the HTR/AC fuse and if it has continuity then that wire needs to power the DRAC module.

 

[sweetk30]

looked in my buddys truck today with no dash pad.

i was right . heater blower motor speed switch plug.

 

[emoo99]

finally.. i got it figured it out.. i disconnected the plug at the drac, got no voltage at the brown wire on the plug in run position.. removed the gauges and checked all connections, disconnecting and reconnecting plugs.. keyed on.. and the speedo zereo'd out thanks for all your help guys.. i hope that had something to do with my check engine light coming on after 15-20 mins of driving..

 

[jltait]

That looks like the hot start module connector. it give the fuel pump a longer ON pulse via the fuel pump relay w/o looking for oil pressure. If that is what it is, then it is designed to ensure a startup even if the fuel system gets hot and vapor locks. The extended ON pulse to the fuel pump would burp it out I guess. I have read about these on another site. They usually only came on higher GVW trucks though, but that sure looks like it.
Jason