OK, I am buying an aftermarket tach since the stock one is acting up. I have done a search on the boards for info and I found a lot but I still have two quick questions. I downloaded the instructions online and their are four wires to hook up. I know exaclty where two of them should go (from searching), but there are two wires that I am still unsure of. I just need to know what color wire thes wires should go to under the dash. These are:

A white wire from the aftermarket tach to a 12V dash light source
A red wire from the aftermarket tach to a 12V ignition switch (I think it is a pink wire?)

If it matters, the one that I am getting is an Autometer Sport-Comp 5" 8000 RPM tachometer.

Thank you very much in advance for your help.

 

for the last 2 wires, on will be a ground and the other will be the tach signal itself

 

in the fusebox there should be a fuse marked interior lamps for the white, and there should also be a space marked IGN for the red wire...

 

Well, I checked my fusebox. I'm pretty sure I found the one for the lights (it says INST/LPS), but can't find one marked IGN. These are the fuses I do have, though if it will help:

ECM, INJ 1, INJ 2, SIR, TURN B/U, GAUGES, TAIL, HTR/AC, FAN, ACC, ARC, RADIO, INST/LPS, WIPER, STOP HAZ, CRK, VATS, LID

I also have a mysterious fuse located near my battery on the fender. It is a 20 amp fuse and the two wires are orange and red, if that helps.

Anyway, thanks for the help so far.

 

now that I think about it, the terminal in the box marked IGN doesn't have a fuse in it, it was just and open terminal. my car is also a 91...

 

if u cant find the IGN terminal, it should be possible to use the RADIO terminal, since that is a swtiched source, or that might be the memory power, cant remember

 

I have a spot for IGN on my fusebox, but there is nothing in it and it has been that way since I bought it. I might try tapping into the RADIO if I can't find anything else.

 

I have another slight problem. I know that the aftermarket tach has a green wire that is supposed to hook up to the coil via a white wire. The thing is that there are two white wires connected to the coil. One goes from the coil to the distributor and the other wire goes from the coil into the wiring harness to the instrument panel (according to a wiring diagram I found). Does anyone know which white wire I am supposed to tap into?

 

the white wire that goes into the harness to the instrument panel...that is the factory tach lead.

 

Thanks, that is what I was thinking but I wanted to make sure. I didn't realize it was going to be this complicated to install a tach. I've wired stuff up before but this is definetely a new challenge for me. All I have to do now is find a 12V ignition switch wire to tap into (there are a ton of wires under the steering column!). Thanks for the help so far :hail: . I owe you guys one.

 

I suggest using the IGN spot we discussed above, that's where mine is hooked up...

 

There is nothing hooked up to the IGN spot. There is no fuse in the slot nor are there any wires leading to or from it. Any other ideas?

 

That's the way it is supposed to be. You make up a terminal with a flat spade type and plug it into the slot marked IGN. That is where mine is plugged into for my shift lite. That's all you need to do to get the power.

 

Oh, OK. I understand now. People were telling me what to do the whole time but I didn't get it until now. I feel like a newbie . Thanks for the help everyone, now I know exactly what to do.

 

No problem man, we've all been there and done that.

 

thanks cc 82z, I should have clarified HOW to hook it up earlier...

 

Ya i know that this thread is super old,but didnt want 2 start a new thread. Super fast question. I have a VDO top eliminator tach and am wondering if i remove the fac. tach would i be able to somehow plug some of the wires coming off the VDO into the fac. instrument panel slots that the fac tach was plugged into? Thanks