72 Mustang Mach 1 tachometer cluster and gauge conversion

Transcription

1 72 Mustang Mach 1 tachmeter cluster and gauge cnversin Dated: (drafted by a Chevy persn wrking n his first Frd -nt gd-) The fllwing infrmatin pertains t hw I went abut cnverting the standard dash cluster with warning lamps (n clck, n gauges) t a tachmeter perfrmance cluster. I als installed new Aut Meter (il press, water temp, vltage) gauges int a new center dash cnsle. I purchased a used tach cluster wire harness n Ebay that was riginally in a 73 mustang. The harness was damaged but all I wanted r needed was the 12-pin plug fr my cnversin. I purchased a new center dash cnsle fr the gauges. I als purchased tw used center cnsles with gauges ff f Ebay (it tk 2 t just get gd gauges). But I decided t nt use the gauges because I wanted a vltage gauge in place f the wrthless AMP gauge. I mdified ne f the rear gauge enclsures fr AutGage 1 1/2 gauges. These gauges have smewhat the same lk as the factry gauges. The riginal sending units fr the warning lamps will be remved and replaced with the new units that came with the gauge kit. If yu are adding factry gauges, yu will need t replace the sending unit fr il pressure (the existing ne fr the warning lamp will nt wrk). Yu will need t run a regulated 12v pwer supply t the factry gauges. Install a metal terminal nt a new wire and run the wire frm the 12-pin plug (pin 8) t the factry il & temp gauges. I persnally wuld nt waste my time trying t wire in a factry AMP gauge. The riginal il pressure & temperature signal wires that were used fr the warning lamps in the dash cluster will be reused fr the gauges. I m saving the factry gauges, riginal center dash cnsle, the riginal speedmeter cluster with the 18-pin plug fr the next wner. This will give them the ptin t revert back t the riginal cnfiguratin r cnvert t factry gauges. The standard nn-tach cluster wiring harness [C-29] has an 18-pin plug (N Tach) where the tach cluster wiring harness has a 12-pin plug (Tach). A 12-pin plug is a must have requirement. If yu can t lcate a tach cluster wiring harness, it wuld nt be that difficult t take the existing 18-pin plug and cut a sectin ut and glue back tgether. Mre detail infrmatin is available later in this dcument pertaining t this idea. 1

2 Getting started steps: Discnnect the negative battery cable. Remve the steering wheel and turn signal handle (gives needed rm t wrk). Remve the dash pad. Remve the steering wheel cllar (helps in remving the speedmeter bezel). Remve the instrument cluster. (I discnnected the speedmeter cable frm the transmissin t get extra slack t pull the speedmeter cluster ut t where I culd remve the cable). Remve the center dash cnsle if adding gauges. Discnnect the ignitin switch plug (ptinal). Cmparing the 18-pin circuit t a 12-pin circuit prir t cnversin: The pins marked in red will be pulled ut f the existing 18-pin plug and inserted int the tach 12-pin plug. The pins marked in blue will be pulled ut and rewired t a signal stud n the il pressure r temperature gauges. Missing wires fr the existing 18-pin plug are marked in green. Only the il pressure and water temperature wires will have the metal terminal remved s they can be wired t the center cnsle gauges. WIRE CHART 1: Tach 18-pin NT 12-pin Pin Wire circuit/clr Descriptin Pin 1 -n pin- -nne- 2 -n pin- -nne /white-lt blue stripe RH turn signal 3 4 3/lt green-white stripe LH turn signal /black-lt green hash Accy feed frm ignitin switch 7 48/black Blind circuit (hld resister wire) 6 29/yellw-white stripe Fuel gauge t fuel sender 6 7* -n wire - Regulated vltage t gauges 8 8** -n wire- Alternatr warning lamp 9 31/white-red stripe Oil pressure lamp 10*** 54/lt green yellw stripe center clck 12v /purple-white stripe Brake warning lamp /red-white stripe (2) Water temperature lamp /red-yellw hash Warning lamps feed /black Grund circuit n pin- -nne- 16 -n pin- -nne /lt green-black stripe High beam lamp /lt blue-red stripe Instrument panel lamps feed 12 2

3 * N wiring ging t pin 7. This wire was included nly if the factry gauges were installed. It was used fr the regulated pwer surce (60/black light green dts) fr the gauges. ** There was external wiring t the ALT warning lamp thus pin 8 f the 18-pin plug wasn t being used. Yu culd put a red lamp cver ver the bulb and munt a scket belw the dash if yu want the ALT warning lamp t be seen. The ALT warning lamp circuit will nt be altered by this cnversin. *** The clck wire (pin 10) f the 18-pin plug is nt used with the 12-pin plug s I inserted it int pin 1 f 12-pin plug. This is a blank terminal slt and will wrk t prtect this live clck 12v wire. The center flr cnsle clck has an existing wiring harness fr pwer. Can t find a tachmeter perfrmance cluster harness r plug. Read the fllwing. Create a 12-pin plug frm an 18-pin plug: I had a plan if I culdn t lcate a 12-pin plug. My plan was t cut a sectin ut f the18- pin plug and re-glue the tw end sectins back tgether t frm a new plug. The 2 plugs are the same except fr the length (18-pin plug is 11/16 lnger than the 12-pin plug). The fllwing steps wuld frm a new plug: Use a small pwer band saw r hand blade with a fine tth fr cutting plastic. Align the plug n its side s yu can read the pin numbers 1 9. First cut wuld be at pin 4 against the left side supprt. This wuld create 2 sectins: A (pins 1-3 & 16-18) and B (pins 4-9 and 13-15). Cut sectin B at pin 7 against the left side supprt. This wuld decrease the size f sectin B by 11/16 [6 pins (2 rws f 3 pins)]. Sectin B nw has pins 7-9 & Super glue the 2 sectins (A&B) tgether t frm a new 12-pin plug. Thus the name AB Wire chart 2 shw the different pin numbers fr the newly frmed AB plug as cmpared t the standard 12-pin tach plug (wire chart 1). 3

4 WIRE CHART 2 fr the 12-pin plug cmparisn: Factry plug AB plug Tach Tach Pin Wire circuit/clr Descriptin Pin* 1 54/lt green yellw strip Center clck 12v (nt used) 1 2 -n pin- -nne /white-lt blue stripe RH turn signal 3 4 3/lt green-white stripe LH turn signal /lt green-black stripe High beam lamp /yellw-white stripe Fuel gauge t fuel sender /black-lt green hash Accy feed frm ignitin switch 10 48/black Blind circuit (hld resister wire) 8 -n wire - Regulated vltage t gauges /purple-white stripe Brake warning lamp /red-yellw hash Warning lamps feed /black Grund circuit /lt blue-red stripe Instrument panel lamps feed 18 * The AB plug pin numbers are the actual pin numbers that were left n the riginal 18-pin plug after sectins A and B were glued tgether. Pin lcatins 4-6 and have been remved. Example: The Brake warning lamp wire (pin 11) frm the 18-pin plug wuld g t the factry 12-pin plug (pin 9). If using a newly frmed AB plug, the Brake warning lamp wire wuld instead g t (pin 12). Same lcatin, just the actual numbering is different n the AB plug. Mve the wires frm the 18-pin plug t the 12-pin plug. Use wire chart 1 as a reference t mve the wires. If using an AB plug, wire chart 2 shws the new replacement pin numbers fr the newly frmed 12-pin plug. T remve a wire terminal frm the 18-pin plug, put frward pressure n the wire while inserting a small jeweler type screwdriver under the metal terminal t push in the hlding tab (bend upward). Yu shuld be able t pull n the wire t remve the terminal. Label the wire with the pin number befre ging t the next wire r insert the wire directly int the new 12-pin plug. Be sure t label the 2 signal wires (il & temp) that will cnnect ver t the center cnsle gauges. The temperature signal is the terminal that has 2 wires cnnected tgether. 4

5 Befre reinstalling the terminals int the new plug, be sure t bend the tab back ut (bend dwn) s that it clicks when the metal terminal is fully pushed int the plug. Give a slight tug n the wire t make sure it wn t cme back ut. Wiring the tachmeter: Frm 72 Mustang wiring diagrams: At the ignitin plug [C-28] there are tw red-light green striped wires (circuit 16) cnnected tgether at ne pin lcatin. One wire ges t the fuse panel and the ther t the cil. On the tach perfrmance versin, the tw wires are the same size wire (gauge). The wire ging t the fuse panel als ges t the input lead f the tach. The utput lead is a resister wire (larger size) and ges t the engine harness plug [C-27] (t the cil). On the standard nn-tach versin, the tw ignitin wires are different sizes. The smaller sized wire ges t the fuse panel. The larger wire size is the resister wire ging t the engine harness plug [C-27] (t the cil). In bth cases the resister wire ( hms) terminates at the harness plug [C-27]. This ballast resister wire is made f tungsten t with stand heat and it is best t nt cut this wire because it can t be restred in any gd way. Exiting the plug [C-27] n the engine side is a standard nn-resister wire ging t the cil. This is the wire I will cut fr my tach cnversin. Nte: If the tach fails the engine will stp (n 12v t cil). Make the new wiring lng enugh t reach belw the tach cluster s yu will have rm t discnnect the tach leads and be able t insert a jumper. T check the internal wiring f the tach use a gd vlt-hm meter and select the hms R time 1 scale and measure acrss the 2 leads cming ut f the tach. If the meter reads pen r n resistance at all, the tachmeter's internal electric circuit is defective. Sme printed articles say it is k t cut the resister wire at the ignitin switch fr pwer t the tach and then splice back t it the return lead frm the tach. I decided n nt cmprmising the resister wire. This is my preference because I want t allw the next wner t be able t revert back t riginal withut any damage t the resister wire. 5

6 A little mre wrk but desn t cmprmise the resister wire. Parts: 1.35 hm Accel Ballast Resistr (part # ), 2-prng trailer plug (cmes new with bth ends still cnnected), wire end cnnectrs, and wire splices. On the tp f the fuse panel is a green [C-27] plug that cnnects the under dash wiring harness t the engine harness. Frm the engine side f the [C-27] harness plug remve the black wrapping tape frm the harness in the middle f the dash pening t give easy access t the wires. Lcate the red-light green striped wire. Befre yu cut, duble check by using an Ohmmeter t check cntinuity between this wire and the red-light green striped wire at the ignitin switch. Cut the wire at a middle pint in the dash pening t give equal wire length t each side. Munt a ballast resister n the right hand side frame supprt between the dash cluster and radi. I used an existing hle in the supprt fr 5/16 blt. The cut wire cming frm the [C-27] green plug will nt be used. If yu fllwed this wire back thrugh the plug yu wuld see that it is the resister wire frm the ignitin switch ging t the cil. I used liquid electric tape t the end f the wire t prtect it frm being grunded. Make up a new wire with a female spade cnnectr that will reach frm the wire ging t the cil and t the ballast resister. Match the tach plug leads fr clr (red-t-red) t the trailer plug cnnectin s yu will knw which end t cut fr length. Cut the trailer plug wire int tw sectins (lng & shrt). The shrt sectin wires must be lng enugh t be cnnected tgether fr a jumper. The lng sectin will require yu t splice lnger wires t bth ends t be able t reach frm the ignitin surce and the ballast resister t dwn belw the tack cluster. Make a jumper plug by cnnecting the shrt sectin wires tgether. Install a female spade cnnectr t the tach lead trailer plug black wire (male ple) and cnnect the wire t the ther end f the ballast resistr. Lcate the tw red-light green striped wires at the ignitin plug [C-28]. D nt mess with the larger f the 2 wires (it wuld be the resister wire). Splice int the smaller wire and cnnect t the tach lead trailer plug red wire (female ple). 6

7 Test: Cnnect the negative battery cable. Cnnect the ignitin switch plug. When yu turn the ignitin switch ON fr the first time after the installatin f the Ballast Resister, leave it ON s the resister has time t heat up. A new Ballast resister is ging t smke at first t burn ff the il used in the manufacturing prcess. Dn t get caught ff guard when this happens like I did. At this time the dash cluster may be tested fr dash lights, turn signal lamps, brake light, and high beam lamp. Test the trailer plug by inserting the jumper. Turn the ignitin switch n. Shuld have 12 vlts at the psitive side f the cil. Car shuld start and keep running. Remve the jumper and cnnect the trailer and tach plugs tgether t cmplete the cnversin. Start the engine t test tach mvement. Wiring the center dash gauges: I use three different 2-wire discnnect plugs (male/female) fr wiring up the gauges. I pre-wired the gauge cluster using 3 plugs. I als made the plug wires lng enugh s the cnsle culd be tested withut being installed in the dash. Plug 1 (il press & water temp signal) Cnnect the tw signal wires that were remved frm the 18-pin dash cluster t this plug. The wire clr fr the il pressure wire is white with a red stripe. The wire clr fr the temperature wire is red with white stripe (2 wires). Plug 2 (gauge lights) Spliced int the wires leading t the heater cntrl lamp plug [C101] fr the gauge lights. Used the light blue-red stripe wire fr pwer and black wire fr grund. Plug 3 (gauge pwer and grund) spliced int the trailer plug 12v wire ging t the tach fr the gauge pwer. Cnnected the gauge grund wire t the radi grund screw in the frame. Test: Cnnect the negative battery cable. Turn the light switch n t test the gauge lights. Start the engine t test gauges. 7

8 Ntes: I replaced the standard light bulbs in the dash with LED bulbs t help vercme the existing pr lighting f the cluster gauges. Yu need t inspect the cnditin f the blue lamp filters. Replace any filters that appear cludy, frsted, disclred, r melted. The 5X LED Gauge Cluster Light Kit was purchased ff Ebay. Because the new turn signal lamps are nw green LEDs, I was able t d away with the plastic green filter n the back f the speedmeter bezel. I nticed there were 2 wire plugs nt cnnected t anything (ne each under the dash by the drs). I traced the wiring (53/black-lt blue stripes) dwn t find ut that they were fr curtesy lamps. Culd nt lcate any existing scket lcatin s I purchased 2 sckets (that will screw in under the dash) with bulbs. Munted the sckets and cnnected the wiring tgether. I nw have light shining dwn n the flr mats when the dr is pen r when the curtesy lights are turned n. Installed a Custm Autsund USA-230 radi. Fr the accessry pwer (red wire) I spliced int the existing harness [C-102] fr the factry radi. Either ne f the 2 wires (296/white with purple stripe) will wrk. Fr the cnstant 12v surce (range wire) I spliced int the existing harness [C-86] fr the center flr cnsle clck. It als has 2 wires (54/light green with yellw stripe) either ne will wrk Re-install the dash parts in reverse rder f hw yu remved them. This shuld cmplete the cnversin fr the tachmeter and gauges. Hpe this dcument was helpful. N guarantees (implied r nt) that the cnversin instructins listed in this dcument will wrk fr everybdy. It wrked fr my 72 Mach 1 s it s reasnable that it shuld wrk fr anybdy with a Mustang. GOOD LUCK! 8