NEED your help again!!!! Pease

[TDAWG1]

I was hooking up a Tach in my JIMMY. Got it in there the gauge went from 0 when started to pointing straight down. NEED help and ideas, needle does not move when reved. I need pics of your set up to see where I plug in the green wire. The Tach is a Sun Pro ll and it is on an 87 GMC JIMMY 350tbi. Driving me frickin bonkers!!!!!
Thanx to you all
T-DAWG

 

[70jimmy]

go to www.sunpro.com do a search for that model, I put in sunpro II and came up with 16 models, toward bottom of page click on user manual english and it will bring up instructions

 

[readymix]

You plug the green wire onto the pigtail coming out of the ignition module. Look around the distributor cap.

 

[TDAWG1]

did that except that wire is hot and it should not be hot. I do not have an HEI distributor. So coming off of the coil is a white wire with a plug at the end. Test light pulsates but according to the volt meter it is backwards.

 

[readymix]

Did you swap the motor or something?
I was under the impression that all 87's had HEI.

If you swapped the motor or ignition something might not be wired correctly. Does the motor run well?

 

[4xcrazy]

Did you swap the motor or something?
I was under the impression that all 87's had HEI.

If you swapped the motor or ignition something might not be wired correctly. Does the motor run well?

TBI motor, not the same as the old style HEI, seperate ignition coil location, not under the cap,,,although i haven't hooked up tach yet on mine, so i am unsure as to what to hook it to either

 

[gone huntin]

Mine is hooked up to that white wire and it works fine.

 

[Jason4x4]

also, most tachs mave a switch for # of cylinders.

 

[GNERGY]

Hooked mine to the white wire and it worked fine.
Tarey

 

[bp71k5]

Yea, check the tach and make sure the white wire is hooked up to the signal lead and not the +12v lead on the tach.

 

[mudbog42]

Could also be a bad ground or a bad 12v source, seen that happen before. Hope this helps

 

[bot0611]

They usually need the green wire to the coils negative cable.

Check the ground also.

 

[TDAWG1]

Hooked up right. Going to get another tach hook it up then I did also think about my ground and my powersource. But it was fine when I had a tach with an inductive hookup.