I had some trouble finding a clear enough "How To" on the internet for installing a tachometer into my 1988 Toyota Pickup. So I took photos the whole way and and I'm leaving this write up behind so future people like me who don't have a damn clue what they're doing can pull it off in no time. Now there were other write ups on the net and this site, but those either didn't have clear enough photos or instructions or the wires and parts were slightly different from the 1988. So here goes! Hope its helpful to someone. Step 1: Once you've picked out your Tach go ahead and mount it in the desirable place. I chose off the the steering column because hiding the wires was easy from there. Step 2: (Optional) Enlist the help of a K-9 companion for moral support. Step 3: Wiring time. My unit came with these. Refer to your instructions to be sure of your wires. Red: Power White: For the backlight Black: Ground Green: Tach wire Red goes to a power source. My truck had a light switch put into the dash for my offroad lights and I made sure that it only received power when the truck was on and spliced the power wire then soldered into it. Now the white wire should go to your dashboard light dimmer OR you can just hook this wire up to the power with the red wire as I did so the light will always be on when the truck is on. In this pic you can see the dark green wire coming from the light switch and my red and white wires soldered to it and electrical taped. For the black ground wire just find a bolt somewhere either under your dash or in the engine bay that contacts real metal. Not painted. I used one under the dash. **Ignore the red wire that is ground for something other than this tach. Once you've got these 3 wires attached you can fire up the truck and see if the tach lights up. If so.. go to step 4. Step 4: Installing the Tach wire. First thing find a hole in your firewall (the metal barrier separating the engine compartment and your trucks cab) and if there is no hole you must drill one to fit your green tach wire through. A pic of mine: Yup the green wire comes through from the cab and goes right towards the ignition box. Ok, so your going to find your ignition box on top of the drivers side wheel well under the hood. It looks like this: Now from this theirs a plug that has a green wire coming out of it. Your wires may be covered in gunk like mine was so scratch at em and find that green one! You can see it in this photo: Now, this is the one that you cut and solder your green tach wire into. This next picture shows the wire cut and my green tach wire coming in. Now that you soldered and taped your wire go and fire it up and give it some revs. Test drive and enjoy. And once again this is for a 1988 so I'm not claiming this will work for any other year. I hope it helped cuz I wish I had this when I did it!! Hahaha.