rxtuner79

iTrader: (1)

Hi everybody. I haven't posted in a while so I'm not sure who remembers me, but to make a very long story short: Diagnosed with cancer on Jan 21 '05, last chemo on June 29 '05, dad gave me "78" RX-7 which was a project car he never started and was sitting for abour 8-9 years, Make-A-Wish foundation paid Chester County Auto Body a lot of money to restore it, got the car back in November of '05. Ok, so the Make-A-Wish foundation couldn't have the car mechanically worked on, only cosmetic stuff. This included a paint job, new emblems, shined-up wheels with custom-made Mazda center caps, re-upholstered seats, new carpets, new dash and LE guage cluster from a board member in Canada, and a lot of other small stuff. One day (before the restoration) I was letting the car run in my driveway and my cousin said there was an electrical storm in the headlights right before the car died. Since then, we had to hot-wire it to start it. When we did, I would turn the car on and the RPM needle would act as a volt meter, and when I started the engine, instead of reading the RPMs it would shoot up and peg at the redline, still acting as a volt meter. Also, the original owner dicked with the wiring so the headlights were always up and the parking lights were always on. He also installed some wierd toggle switch that was supposed to turn the lights on and off, but didn't really work. Chester County had a friend come in and do some stuff (remove carbon build-up, mess with the wiring, and some other small things). After I got it back, the switch that moved the headlights up and down started to work but when they cam up they always on and the parking lights were still on. I found JPR Imports, an RX specialist, and brought the car to him a couple months ago to have the electrical problems worked out. He had the car starting and running in 3 days, but it took him a while to figure out the rest of the problems. He eventually fixed the headlights and parking lights, and got an original switch for them and installed it. But he said that this RPM guage problem is still kicking his ***. He is still trying to figure it out, but has had no luck. He's been all over the wires, and said he even went into the coils to see what was up, but with no success. If anyone knows anything about this problem, please let me know. I would really like to get this fixed soon and any help is appreciated. Again, the RPM needle is not going from reading volts to RPMs, it's staying at volts and pegging at the top. Once the car is out of the shop I will try to get pictures, and Jim (owner) said it was probably in the top 5% of 1st gens in the country. So that's basically it, the long update/problems, and hopefully someone has run into this problem and can help out. Thank you.

Sorry for the long post

Sgt.Stinkfist

iTrader: (6)

could the tach signal wire be attached wrong? how bout alt. wires, grounds? don't you just love cleaning up after someone else's wiring mess

ZeikHunter

i heard that the SA tach doubled as a voltmeter under certain conditions, like starting or some such.

Sgt.Stinkfist

iTrader: (6)

the tach only acts as a volt meter until the coils start firing/engine starts, then shes just a tach

rxtuner79

iTrader: (1)

I will call Jim and ask if he checked those things. He said it was a HUGE pain in the *** trying to sort out the wiring. Most of the problems were found with the wires the PO screwed with for the headlights.

Keep the comments/suggestions/ideas comming!

Mazdax605

iTrader: (5)

I think the voltmeter/tach setup works through a signal from the alternator,and through the wiring harness that goes over to the external voltage regulator on the drivers side between the strut tower,and the firewall.Do you or your mechanic have a factory shop manual? If not I think they are available on the web,or I can scan the pages you need,and email them toyou.Good luck,and I/we are happy to hear you are doing well.

Chris

Pele

iTrader: (28)

If it's reading voltage and reading higher than 14.5 or so (Doublecheck with an ACTUAL volt meter.) I'd say that external voltage regulator is hosed.

Luckily, it won't cost nearly as much as a whole new alternator which us internal regulator guys need to get when the v-reg goes wonky.

Same thing happened in my Dad's Ford Probe... All the lights in the car blew out. Luckily, the sensitive electronics in the ECU and Stereo had internal voltage regulation... Lucky for YOU, the SA has no such ECU or stereo electronics.

Yark79

Yeah, I've had the same problem with my SA. The voltage regulator on the near the driver side strut tower was the problem. It's just a little box and it's easy to find. It seems like noone, including Mazda carries the correct voltage regulator. All the ones I've seen have too many or too few wires coming out of them. I'm pretty sure one of the wires is used to hold the choke out when you pull it out before starting the car. My regulator doesn't have that wire, so you have to hold the choke out until the car is started, but once it's running, it will stay out and go back in on its own.

rxtuner79

iTrader: (1)

I'm going to email this page to Jim so he can take a look. I talked to him on the phone yesterday and he didn't get into every little thing that he checked, but I will see what he thinks about this stuff. Thanks for all the help, and if anyone else has an idea, please let me know.

oldone

My 1st Gen 1980 was fitted with a 12A when I bought it.Rebuilt the motor and put it back.On starting up I suddenly had the prob as desrcibed.The battery stayed fully charged,even though all the dash warning lights stayed on.Then one morning driving to work it suddenly corrected itself.................
Removed the 12A,fitted a 13B and the problem started all over again.....have done 3 thousand miles so far with all the dash warning lights staying on.I have now just fitted a VDO rpm counter.been through all the wiring and ground (earth) leads,changed the alternator...figured the external reg must be fine cos the battery stays fully charged...??????????????

rxtuner79

iTrader: (1)

Ok, it seems I can't edit my original post (unless I'm going crazy and missed the button), but the alternator was changed before the restoration took place because the old one died. Also, I was told to call next week after he had a little more time to work on the car, so if he hasn't found the problem by then I will email him this page.

By the way, if anyone is in the NJ area (I'm near Philly) and has an RX-anything, I would highly suggest checking out JPR Imports. They specialize in rotaries, and when I pulled up to the shop I was in shock because I had only seen like two or three third gens in in person, and he had quite a few that were amazing and extremely clean, which says a lot about the business. I've been to a few shops in the area, and I can tell by looking at the customers' cars what kind of work is done there. After seeing the first two cars that caught my eye, I could tell he was extremely good at what he does. Here is the website, check it out... http://jprimports.com/

rxtuner79

iTrader: (1)

Any other suggestions? I will be calling Jim back on Wednsday so if anyone has an idea, please let me know.

wankel commando

mine did the same thing..check your alternator output

rxtuner79

iTrader: (1)

Ok, I just emailed this page to Jim. Any other suggestions before he reads this? Thank you everyone for your help.

espresso

You may want to consider getting an FB alternator and doing away with the external regulator entirely. They are much more common and easy to get in the aftermarket, have the regulator onboard like most cars built in this century do ( ), and don't cost insane amounts of money. I would imagine you could wire up the tach as it is on an FB and it should work fine as a tach. You would need to mod the wiring harness a bit to handle the changeover, but it sounds like that would be a really minor thing at this stage in the wiring game... If your regulator is bad, that may be your best option.