Hooking up my new tach.

[Space Monkey]

Ok, so four wires.

Green - Distributor
Red - Battery
White - Lights
Black - Ground

Every time I connect the ground the truck won't start. Disconnect the ground and the truck starts but the tach doesn't work.

It's hot outside and this is annoying me. Help please.

[J Knight]

What are you grounding to and what is your power source?

[Space Monkey]

I tried a couple of different places for the ground. Even ran the wire all the way to the front and grounded it next to the headlight ground. I plugged the battery wire into the port on the fuse box that the cargo light was running off of. I don't have a cargo light so I figured, meh.

[J Knight]

Find another switched hot on the fuse panel and return your ground to the inside of the cab.

[Space Monkey]

Where in the cab is a good place?

[J Knight]

Any bolt or screw on the firewall or dash. There are a few ground like that from the factory, its best to tie in to those.

[dieseldawg142]

if you look above your vent in the kick panel,(driver's side) there's a ground bus bar up there

[MalibuSSwagon]

Also, use a power port on the F/B that is hot in run only.

Are you sure you connected the green wire to the tach terminal and its not touching the other terminals? I like to cover my spade connectors with heat shrink to prevent cross-connections.

[Space Monkey]

Ok, so I moved the ground and that got the light on the tach to work but I still can't start the truck. Nothing is touching anything else. Everything SEEMS good but it still won't work.

[J Knight]

Originally Posted by Space Monkey

Ok, so I moved the ground and that got the light on the tach to work but I still can't start the truck. Nothing is touching anything else. Everything SEEMS good but it still won't work.

Hot is the green wire attached to the dist?

[Space Monkey]

Yessir.

[king-918]

Sounds like a internal short
Posted via Mobile Device

[J Knight]

Originally Posted by J Knight

Hot is the green wire attached to the dist?

Originally Posted by Space Monkey

Yessir.

LOL, I meant HOW is the green wire attached to the dist? I it connected to a insolated terminal?

[Space Monkey]

lol ok...

I got a double connector from O'rielly's that you just hook the wires to and plug into the distributor.

[SkinnyG]

If it's HEI - there should be a male spade connecter under the square part of the cap, labeled "TACH" - it will not likely share any other wiring.

If you are not using HEI - the green wire goes to coil NEG (-) connection.

[Space Monkey]

Yeah, it's connected to the HEI, to the spade labeled TACH.



The connector I have is kinda like this.

[J Knight]

Originally Posted by Space Monkey

Ok, so I moved the ground and that got the light on the tach to work but I still can't start the truck. Nothing is touching anything else. Everything SEEMS good but it still won't work.

The only thing I can think of is the cargo light terminal is not a good power source or the tach is defective.

[Space Monkey]

Can I hook it up straight to the battery terminal just to see if it works?

[J Knight]

Originally Posted by Space Monkey

Can I hook it up straight to the battery terminal just to see if it works?

Yes

[Space Monkey]

Ok well i did that and the wires on the tach melted and almost burned up my truck. Had to yank them out as they tried to burn...

So I'm guessing bad tach.

[MalibuSSwagon]

Damn, I'd say so

[J Knight]

Holy crap! Was this a "new" or "used" tach?

[Space Monkey]

Used. Off of Ebay.

[cmyc5575]

Originally Posted by Space Monkey

Used. Off of Ebay.

That was most likly the reason why he sold it, sorry man, but thats a chance you take when buying used. I know first hand when i bought a used saw and caught on fire when i plugged into the wall the first time.

[Space Monkey]

It was only $20 shipped so meh.

Guess I'll buy a new one.