Correct under dash harness for Tachometer

[Gary Lewis]

its for 1983 not 86 if it makes any difference and yes I have a factory style tach cluster.

Barry - With two threads going on essentially the same topic you may get info that is seemingly at odds with each other. Given that, I'm going to post a link back to this thread in the other one so everyone knows they are connected.

But Jonathan/Ford F834 is 100% right. The harness you need is very long, headlight-to-headlight across around and through the dash, and there are lots of little wiring changes over the years. So you'd have to concentrate your search to probably 1982 to 1984 trucks. And even then I'm not sure it would be plug and play.

If I were doing it I'd almost for sure go with the approach Jonathan suggested of getting the 18 pin connector and a bit of wire with it, and grafting it into your system. Here's what I think the changes would be:

• Pin Swaps: You'd have to pull the pins out of the 18 pin connector and your 14-pin connector, and put yours into the 18 pin connector in the positions shown in the spreadsheet

• Ammeter: For this I'd have Rocketman change the ammeter in your new cluster to a volt meter. Plus you'd have some very minor wiring to do.

• Alternator Warning Light: If you have a volt meter you don't need the warning light. So you could just put a resistor across the two wires, and that would bootstrap the alternator.

• Oil Pressure Gauge: I think you have a switch instead of a sender, so you'd have to change that out on the engine. Not a big deal.

To my way of thinking that would be FAR easier than replacing the whole harness.

[Ford F834]

its for 1983 not 86 if it makes any difference and yes I have a factory style tach cluster.

Barry, I have extracted the wiring from three different Bullnose trucks. It is a BIG job, and the ones I did were all fairly simple (IDI diesels and non-computer non-catalyst 5.8 HO). The only reasons I can think to justify a whole truck wire swap would be 1) your existing harness being so badly hacked and damaged that it isn’t worth repairing or 2) you want to add multiple options like factory cruise, interior lighting group, power door options etc., and can find a donor that has everything you want to add. I will say this again, finding a bullnose harness in good enough condition to use is becoming a very tall order. I would like to replace the poor condition harness in my 1981, but I have yet to find one that isn’t worse than what I have. I’ve been looking at four different junkyards for the past couple of years and no luck. I have a diesel harness, and may consider modifying it. My suspicion is even if you find a good harness, you may end up doing more work to it to adapt it than you would to just modify for the tach cluster.