Seperate of the FAQ section, if you "join" autozone, it will open up a tech section for the truck and you can use the schematics to run your tach wire off the (-) coil lead. I believe it is a grey wire that you are looking for. However, the speedometer cable was used in later years than 88', but depending on the engine configuration V8's may be different than v6's.

 

the autozone site uses the chilton manual and just scans its pages. i cant find the manual for this truck by chilton or haynes and i cant find the book at the store itself or the library. as i have stressed the 1990 wiring is different and a 1989 gauge wont even work right in the '88. i just want to bypass all the wiring harness so i can avoid the shorts or w/e is going on.. it cant just be the gray wire going in there because the arm in the sender has 3 wires going to it.

 

Wait... 87-96 clusters are not plug n' play? Now I'm confused

 

they are plug n play but when u switch em around ull get the same results u would hooking a sega genesis controller into an atari or vice versa.. thats my point.. if someone here thinks the gauge from the 1989-96 would be the same set up as my '88 then i wonder if someone else with knowledge of their model can tell me which three wires in the back of the "plug n play" connector correspond to the 3 wires that link up to the arm in the fuel sending unit..?

 

Ohhh, gotcha. So you have an 89-96 cluster in your 88 and your gas gauge does not function?? Everything else is fine?

 

I was referring to the tach output/input, BUT perhaps your 88' does not have the barrel connectors in the back of the instrument cluster. Sorry, just trying to help. FYI, I had to rewire my fuel circuit as well, after swapping engines it just seemed the right thing to do, but...... good luck.

 

i have an 89 gauge that dont work right but im back to using the 88 which works at times. i was just making a point with the 89 reference.

if the tach shows RPMs then know the 88 doesnt have that and the 89 does which caused some issues..

yea siggie what im saying is no one can explain to me which wires going into the back of the gauge cluster are the same 3 wires that come from the gas tank from the sending arm which has 3 wire clamps on it. thats my oint all along, no one will tell me which three wires it is so i can just hook the gauge cluster in a straight line to my sending arm and just end this whole ordeal.. no one will even tell me if that solution would work.. its ridiculous.

 

Are the tach's mechanical or electrical? I was hoping the tach would just not work and the rest would haha.

What generations are the clusters wired in does anyone know?? 87-88 and 89-96??

Sounds like the 3 wires are there...and aren't connected to the wrong instrument, but perhaps in the wrong order (pos & neg reversed or switched with the signal wire etc).

 

i really dont know what u mean by the tach. on the 89 cluster u got a RPM hand then a speedometer in the middle that goes to like 125 then u got the oil, bat, gas, and heat gauge. on the 88 u got a huge gas gauge then u have a seat belt warniong light in place of the small gas gauge and no RPMs. the speed goes to 85.. the plug n play hooks in the same but when i put the 89 gauge in some of the lights for the wiper fluid lights up and the check engine, thats it. i dont think they are compatable but that is not my issue. my 89 gauge could be messed up but i doubt it but idk for sure.. theres gotta be sum issue with different gauges anyways and trhe same connecter types hints why i referenced a genesis controller in an atari.. as i ill say for the umpteenth time i am trying to figure out wtf the wires that go into the plugs mean so i can hook my gas arm directly to my gas gauge..

 

Umm.....your "RPM gauge" is called a Tach. We understand your damn question, we are asking questions in the process of troubleshooting chill out.