Help with ISSPRO R8503 tach install

[Sri Ram]

I have this tach and want to install. I don't forsee any problem with the magnets, sensor mount, etc. But what about getting power to this thing. Where do I tap into the dash lights circuit? Should it have its own fuse? Any help appreciated.

 

[JLEONARD]

I tapped into the light for the ash tray for my gage lighting.

Easy access and it dims.

 

[Sri Ram]

I tapped into the light for the ash tray for my gage lighting.

Easy access and it dims.

Huh, I wouldn't have thought of that one…Did you crimp or solder and heat shrink?

 

[dpuckett]

THere is a brown wire coming off the headlight switch that is the dimmer.



I used the wire coming from the ignition switch for the power for the tach. Just follow the instructions and you should be fine. The magnets have stayed on my h-balancer for almost 2 years.



Daniel

 

[JLEONARD]

Did you crimp or solder and heat shrink

Crimped and taped.

 

[Greenleaf]

Maybe I'll out of line here. But... ... ... ... don't the 91. 5 and up trucks have the tack wire harness factory installed?????? Everything is right there from day the truck was driven out the factory door????????????NO????



Perhaps that is the 1992 models and up. I have one of each but YOUR talking about a truck right at the CPL change. (1991. 5)

 

[tugboatphil]

Maybe I'll out of line here. But. .

Scott,



You are out of line!

 

[Greenleaf]

I know... . I spelled "tach" wrong.

 

[JLEONARD]

I know... . I spelled "tach" wrong

Very tachy Scott... very tachy indeed... . :-laf :-laf



I love a guy who leads with his chin.

 

[Sri Ram]

You guys have been in here too long :-laf

Scott, I looked for the factory harness, even ordered the ISSPRO mating connector, but to no avail. My 91. 5 don't have it, at least as far as I can tell.



At this point, I've got the magnets and sensor on and the tach mounted. Now, to run the wires. Where do y'all normally run them through the firewall?

I used the wire coming from the ignition switch for the power for the tach.

dpuckett: which wire coming off the ignition? There're about a half-dozen of 'em!

 

[bgilbert]

A test light works wonders for finding 12V and ignition switched power. What I've done in the past is while you have the dash bezel and speedo cluster out, find 12V and ig switched power in one the wiring harness on driver side that plugs into the back of the speedo cluster. Then you can use a quick splice on that harness for what you need.



There is a 2" rubber gromet for running wires through the firewall.

 

[Greenleaf]

The factory tach harness is about 4 inches directly in front of (or in behind) the head lamp switch. It's taped to that same wire harness that is leading into/out of the head lamp switch area. The connector is flat with four terminals and is grey or black in color.



Wish you had that. Makes work easy.

 

[MeritBadge]

I'm probably too late... but anyway. Stick a fuse tap into fuse #14, should be your instrument panel light fuse, 3 amp purple. Then put a spade connector on your wire. easy as pie, ground it wherever suitalbe



like bgilbert said, make a hole in your grommet and run wire through there



i take it the tach works good, no troubles?

 

[Sri Ram]

i take it the tach works good, no troubles?

yep, works just like it should, idling at 800rpm…



Thanks everyone for your help. I ended up tapping into the 'gauges' fuse right as the wire comes off the fuse. I did use the ash receiver light as the power for the bulb. Very handy! Gauge light comes on with parking lights, just like the rest of the dash cluster.