Blitzed

Hi All, Finishing up the re-connecting of wires from my dash restoration. Want to be sure and double check before I button it all up. Car runs no, issues to this point. Have the same wiring harness part number as the start of this post 21755-4400 (73 240Z). See attached. Connects to blower motor and blower switch. The ground (black) coming off this harness, I had marked as radio ground. Like a DA didn't take a pic of where this ground wire would have attached to the stock radio. Is it as easy as pick one of the mounting screw on either side of the radio to ground? My FSM is delete of a radio wiring diagram. Also harness number 24026-N3300 carries the three small panel lights (fan switch and heater/vent controls) in the dash. This harness also includes a black ground. I marked as console ground. Again DA no pic upon removal. Where is the this ground mounted? (back of the fan switch plate?). Thank you for your help.

Hi Sean, Thanks for the details. Too late for my project now, maybe in the future. Went back to the 240z tach using the stock harness. The dash restoration looks great back in the car. The swap of 280z parts into the 240z tach can is pretty easy, where the original post falls down is whats next? Converting a 280z tach that uses negative coil post signal on to 240z harness receiving a signal from the positive post coil signal, doesn't work. Maybe why the post stops after the parts conversion, too many variables/changes and components to add to get the 280z tach to function with the stock 240z harness. Started the tread with the comment, "converting the tach now for future ignition upgrades". Stock distributor (with pertronix upgrade) and stock coil, tough to accomplish the conversion without a adding and changing a bunch of the stock wiring and ignition components. Not as easy as running a wire the neg side of the coil. Engine is coming out next month for a rebuild, will revisit the tach. Thanks again for the details.

Sorry tach pic

Thanks Zed Head, all good stuff. Even if I owned a meter wouldn't know how to use it or understand the numbers. So this project is over my head. Dash is hung in the car, would like to leave it there moving forward. All previous electrical issues were all caused by the hazard switch. Reversed the wires in the small can in the dash and turn signals, brake lights are all functioning perfectly now. Didn't realize how critical this switch is to bunch of functions. Tach is the only challenge. Understand your concerns about the wires. The dash wiring harness is untouched, zero splices, additional electrical tape or butt connectors anywhere, including both side of the firewall. Pic attached shows the tach wiring from the functioning 240Z tach (prior to removal and swap). So if it functioned with this set -up it's safe to say power is power and ground is ground. Followed the instructions with the internal swapped and reverse the wires per the harness on the 280z tach and internals. The 280 tach I swapped is exactly like the tach pics in the instructions above (ground and power reversed). So let assume that's correct. Ran a wire from the post directly to the negative side of the coil, the only measurement I can give you, it's live. as I grab the connection while the car was running. So current could be the issue with the tach not working, can anything be added in-line to the coil/post wire (the only wire I can touch with the dash installed) to reduce the current?. Sure this rambling drives electrical engineer's crazy. Thanks for all the advice.

Hi Zcarfever, Just replaced the tires on my 240Z. Received a ton of advice on the site. Landed on 205 60 15. The 60's fill the fender well nicely. You lose a little patch width with the 60's, no rubbing issues front or back. Pic attached.

Hi Zed Head, The 240z tach with the wire loop worked fine. The 280z tach internal swap into the 240 can will not work. Not sure how to clearly express it. Needle does not move or pulse when the car is running, turn signal lights in the tach do not work. The only thing operating on the tach are the dash lights (in the gauge in- line with the dimmer). Duffy Mohoney - please explain coil on the plug. Don't see this in the conversion post attached. Using the stock 4 pin connector with the white wire loop still intact in the connector (coming off the back of the tach) In the connector coming off the tach (female), which pin is coil? The current black ground, white/red power and the white wire loop in the other positions. Thank you,

Hi Zed Head, Hope all is well. The work on the Z is very fluid right now, work happening in between post. Purchased a used 280z tach. Followed the instruction in the post to swap into a 240Z can. No additional mods were made. Using the 240Z wiring harness and original 4 pin connector. Ran a wire from the 280z internal post to the negative side of the coil, per instructions have power in the wire. Tach will not operate. Turn signal lights do not function but hazard lights function (arrows on the tach). Moved one of the hazard switch wires (2) into the alternative input hole (3) in the can (in the dash). Now the headlights and brake lights all work. Only thing not functioning are the tach and turn signals. Progress.

Hi All, Hope all is well. After sending the "tach not working" post last night, searched the archives on the site, may have touch on the electrical issue. Another lesson in too many changes at once! The original 73 240z hazard light switch broke, the center wire on the knob post broke off (plugs into the small can in dash). Purchased a used hazard light switch from the same reputable source in AZ as the tach (and untested). So the turn signal and brake light issues can all be related to the replacement hazard switch, yes? While the dash and wiring are in the car intact, would like to test if the issues are related to the replacement hazard switch. The small can in the dash has three inputs holes for the two wire plugs, center seems to be static. does it matter which input hole for the second wire? Anyone experienced the issue with the post wire breaking and can it be repaired? broke at the back end of the post, can't solder a slice, not enough of the original wire exposed at the end of the post. Wire appears to travel into the steel post and is crimped at the knob end. Would like to repair the original and test. Tach is still not functioning, all conversion steps have been confirmed and reconfirmed . Without a clear method to test the tach internal function, assume the 280z tach internals are the issue. Will re-install the 240Z internal and live with the tach as is. Thanks for all the info.

Hi All, Well the dash re-instillation did not go well. Dash will be in and out of the car for a third time. Sorry for the lengthy response but I have compounding issues now. The 280Z tach conversion into the 240Z housing did not work as listed above. Tach needle is not moving, thought a missed a step so removed the dash/tach and covered all steps again, second re-install, tach needle is not moving. Worst case scenario, my concern from the start no way to test the function of a used tach before turning the key and praying it will work. Purchased the used tach from a reputable source in AZ but they do not test used parts before shipping. So I'm searching for another 280Z tach. Bigger problems now. All the cars electronics functioned well before the dash removal, now electrical issues. Turn signals - Do not operate. No green arrow lights and a single weak click (right not left) from the TS relay (can under the drivers side) then stops. Can I assume the lights not working could be related to the tach not working? Will the tach not working effect the TS switch? Hazard lights function - green arrows on tach light and relay clicks fine from the passenger side. So I know the lights on the tach function. Brake lights - Do not work now. Headlights- Worked before the dash removal and worked upon the first re-install, turned them off, they will not come back on. Running lights -work fine. All dash gauges / gauge lights (including the tach), clock, emergency brake light and high beam light , dimmer, and interior lights work fine. Car starts and runs fine. Will a short in the system begin to take down relays? Have a FSM with a 240Z wiring diagram (no electrical experience), it's great I can locate colors of wires. What I need to understand is where the connectors/connections located? Any advise would be appreciated.

Hi All, So I'll be the test rat, replacement 280 tach internals can be obtained. If the jump wire is installed (with the tach and dash out), is there a method of testing the tachs operating function to ensure it will work before painfully re-installing all components turning the key and praying the needle will move? ZCLOCKS - Your 20 mins from my home. I can send the tach to you with the jump wire change made (complete in the 240z housing). Can you test the function/compare to unchanged 280 internal? Or are there to many other variables without the ignition circuit in-line to consider a function test successful? Goal - make all these little changes under the dash before re installation to support future ignition upgrade. Thank you for the advice.

Hi All, Thanks for the responses. Sounds like this is uncharted waters with the 280Z tach internals. Was hoping for confirmation. Again, the goal is to make all the changes / upgrades under the dash while it's out of the car. Yes, this is not the norm, but the norm appears to be a tach that is very unpredictable in function when adding ignition mods. Adding components to the tach lead often is the fix. Any other suggestion / upgrades to the other gauges or switches? All are original to the car, including the radio. Thanks again.

Hi All, Hope all are well. Pulled the dash to restore the heater box / heater core, replace heater hoses, clean and replace all vents. Clock was not working, sent to ZClocks. While the dash is out like to updated the tach for future ignition changes/upgrades. Purchased a 77 280Z tach and replaced the internals into the 240Z housing, per instruction on in this post. Has anyone performed this resister jump on the 280Z tach internals? https://www.youtube.com/watch?v=Q5plL3aZbzA First question, once you add the jump wire do you remove the 5 ohm resister? Limited electronic board experience, assume if the resister is still on the board wouldn't it still draw current? Second question assuming the jump wire takes the 5 ohm resister out of the coil signal, what potential issues can this cause with the stock set-up listed below? Reason for doing this now with the dash out, never want to remove the dash again or try and remove the tach on my back. Understand some of the ignition upgrades have internal signal reducers which impact the tach's performance. 73 -240Z, L28 N42 head and block, round top SU's. Current - stock distributor, Pertronix upgrade, stock coil. Future - MSD, matchbox or other. Any other upgrades / advice to other dash components are welcome. As mentioned this will be a one and done dash removal. Stay safe and well.

Thanks All, New SS rear flex brake lines and emergency brake mounts (for the Maxima caliper) are on the way. Pissed I'm paying for this work twice. Need to replace the rear hard SS lines going to the frame mount. Previous caretaker of the car used vise grips on the fitting (left and right). Are the only options to buy a complete set of SS hard lines ($350.00) or make them? Any suppliers that sell the SS hard lines piece by piece? 73 240Z Making option: what dia SS line is needed and what is the flare fitting tread size and pitch? Thanks again.

Hi Grannyknot, Thank you for the advise and images, never considered the caliper position. It appears the shop, re-purposed my old drum flex lines with new fittings may be why the caliper is in the 10:00 clock position, shorter brake lines. They fabbed a emergency brake cable mount welding the end mount (clip to hold the cable) from the old drum EBC set-up . These are the tack welds you're seeing in the photo. Since I didn't procure the parts and have zero instructions to the conversion. Two questions: Is there a preferred rear caliper position on the rear rotor for braking performance? 10:00 versus 1:00? They crossed over the emergency brake cables (original stock) above the diff. Was this to make the cables shorter to fit to the calipers? Or a common process for the disc conversion? Thanks again.

Hi All, Had a service provider preform a rear disc brake conversion on a 73 240Z. Basically the stage one kit from MSA. Maxima calipers with 280z rotors. Before the car went into the shop the suspension was upgraded with new springs and struts. eibach springs 1" lower then stock. When the car was delivered from the service provider, began to experience a clunking in the rear of the car (drivers side first, then pass). Upon inspection for loose gland nut / strut or suspension issues, discovered (when the car was on the ground and the suspension was fully loaded) the SS hard brake line mount (L bracket mounted on the sub frame) is making contact with the emergency brake line mount on the Maxima caliper. See photos attached. This is the same on both sides very tight space to coexist with an active suspension. The SS hard line mount (on frame) is sitting slightly above the emergency brake line bracket at idle. Upon compression clunk, clunk, as it passes below and return to idle. Please respond if you've preformed this specific rear brake conversion. Not only is this annoying but very dangerous as the flex brake line is also making contact and could be pinched/cut. Do you have to re-position the frame mount slightly forward? Are there other emergency brake line brackets? or other to gain clearance necessary so the mounts can pass each other without contact. . Thank you.

Thank you for the parts options.

Hi All, I own 2 R200 diffs. Need to deal with the parts at hand. The question still remains, which of the R200 diffs is the less expensive for CV' conversion? Clip in or bolt on to flanges? Only rebuilding one. Thanks for the advice.

Flexibility and options with the engine power/mods. Engine NA (L28, N42 block and head) will be rebuilt or swapped this year. Not sure the direction at this point. Diff is being replaced/upgraded as part of the drive train overhaul. Installed a 5 speed trans, rebuilt the drive shaft and now the R200 diff upgrade. I'm working backwards, from the back of the car forward to handle additional power.

Hi Zed Head, Our mind sets are the same with the diff "low budget with high value". Both are long nose carriers and appear to be the same size. I'll check for the retaining clips or clip grooves in the axle holes of the Yoke size DAT-110 300ZX. R200 with the haft axle flanges installed and the DAT-110 yoke. This diff came out of a running car (240Z) with stock half shafts and stock sub axle mounts (at the wheel). Are there any bolt in options for CV axles for this set up without mods? Or are the options limited to weld in sub flanges and other mods to install? Easy is not always cheaper. R200 diff with DAT-110 300ZX yoke, if retaining clips are present, less expense to find and install CV axles with the stock sub axle mounts (at the wheel) ? Or more mods? Reason for retaining unused ring set, both diffs are the same ratio, not for resale, future replacement part if needed. Thanks for the info.

Hi All, Happy 2020! Recently acquired two Datsun R200 diffs. I'm a novice with Z the drive train configs so bear with me. The diffs are the same gear ratio. One has the input yoke listed below as DAT 110 and half shaft flanges on each side. The other has the input yoke listed as DAT 110 300ZX with no half shaft flanges. Both are round input yokes, one smaller than the other. In addition to the yoke comparison below, how can I determine which Z these diff's came from, Z31 or Z32. Serial numbers ? If the assumption (based on the image below) one is from a 280ZX and the other is from a 300ZX, is one diff preferred or better over the other? Reason I'm asking is only one will be completely rebuilt. Would like to spend the money on the preferred diff and keep the other for the ring set. Also will acquire CV axles for the best rebuilt diff. Is one diff better for with less modifications and less money to convert to CV's ? 73 240Z stock rear suspension config. Thanks for the advice.

Hi All, So, one vote yes to the wheel hub position moving out and one vote no, same position with the spacer. Anyone on- line preformed the vented rotor and Toyota caliber upgrade on a stock 240Z brake and wheel assembly? Thanks for the info. Andrew

Hi All, With regards to the Toyota vented brake upgrade front disk. Will the spacer required change the wheel hub position from the stock position (front only)? Meaning will the spacer move the wheel hub /rim/ tire further out in the fender well? Tires are already tight to the inside of the fender running 205's no flares. thanks , Andrew

Thanks Mike and Mike, Just wanted to cut to point. Was not in the market for new wheels and tires. Unfortunately the disk brake upgrade (front and rear), with the 14" Western Wheels Turbines I had on the car cleared the caliber in the rear but would not clear the slightly larger caliper in the front (1/8" off). Two options, tow the car home or pull the trigger on larger 15" wheels and drive home. All had to done quickly, not a good position. BTW- The original (1976) set of Western Wheel Turbines are on the classified board. Wheels are in excellent condition and the tires are brand new (less then 100 miles). Nothing like large unexpected expenses. Thanks again for the info and confirmation. Andrew

Hi All, First of all I've read several wheel fitment threads on the site. Please don't' shoot the messenger, still confused. Pushed into buying wheels and tires quickly (not good). Converted to vented rotors / rear disk brake conversion and now the 14" wheels do not fit over the front calipers. This would all be ok if the car was in my garage but it's 30 miles from my home in a service garage. The shame of spending dollars and having the car towed home, just doesn't seem right. Please only comment if you've have a similar config listed below. Only looking for confirmation on stock body (no flares) 240Z's. Specs: 1973 240Z with air dam (front valence removed), stock fenders, Eibach progressive springs on stock shock housings. Car is slightly lowered with the rear shock spacers installed. Will 15" x 7" 0 offset wheels and 205 x 60 x 15 tires fit without any issues? Need to purchase and deliver to get the car home. Thank you for your help,

View Advert Original set of Western Wheels Turbines and tires 240Z Nice set of 14" x 5.5 Western Wheel Turbines (Installed 1976) for sale. Wheels are in great shape, no curb rash, new center caps Z logo. Tire are brand new 14 x 195 x 70. $600.00 Local pick only. Orange County, CA. Advertiser Blitzed Date 10/13/2019 Price $600.00 Category Parts for Sale