TI voltage regulator

[Rex T.]

What years were the TI voltage regulators used on Corvettes and what was the advantage of them over the conventional regulator?

Thanks,
Rex

[Joe L.]

Re: TI voltage regulator

Rex-----

I believe that 1965 and 1966 were the only years that a transistor-based external voltage regulator was used for certain Corvettes with TI. I'm not 100% sure of that, though. I am sure that they were not used for 1968-71.

The primary advantage of the transistor-based voltage regulator is that it's an all solid-state device. Other external voltage regulators were electro-mechanical devices with "moving parts".

From 1969 onward, all Corvettes used solid state voltage regulators. However, these were internal to the alternators, "miniaturized" compared to the earlier external units, and proved to be very reliable.

I believe that the earlier external, transistorized units can be adapted to other Corvettes originally using an electro-mechanical unit. However, I could not provide any information on such a conversion. Jack Humphrey probably could, though. These units were not just used on Corvettes; they were also used on other GM applications, generally those with high output alternators. I've even seen these Delco transistorized regulators on some aircraft applications.

They come up for sale on eBay from time-to-time.

[Jack H.]

Re: TI voltage regulator

Thanks for the podium, Joe!

There were several versions of the TI voltage regulator (running change improvements) and they were originally factory installed on vehicles with high current demand electrical systems (typically A/C equipped cars). The advantage to being solid state vs. electro-mechanical, was the regulator's FAST response time.

During the time frame when the solid state regulator was offered on some cars as standard equipment, Delco Remy 'featured' it in their service replacement parts catalogs. The correct Chevrolet version of the regulator (1116368 and 1116378 are two known PN's) is a completely transparent 'drop-in' replacement for the conventional 1119515 electro-mechanical voltage regulator.

[Larry L.]

Re: TI voltage regulator

my orig 66 has TI with a 42 amp alternator, and mechanical (point) type regulator. Never been touched.

[Wayne M.]

IMO, Only 1965 w/C60 and K66

which means only L76 and L79 combos. The 1116368 is a rare bird; this one is dated 4H (Aug of 1964). Rex, I believe your interests lie in the 1964 MY, but I don't think they were installed on production 1964 Corvettes. I stand corrected if the '64 or '66 TIM & JG's say otherwise.

To Joe L. and Jack H.: In spite of the parts manuals saying that these were on '66 Corvettes, I don't believe that ever happened. The 1116368 suffered failures due to high voltage discharge when "blower motor, air conditioner, compressor clutch, ignition coil, etc. were (simultaneously) turned off with the ignition switch". (TSB # 1115, April 22, 1965). The interim fix was to add an external suppression diode harness # 2977253 at the voltage regulator. This shows up in '65 AIM UPC K66, sheet 5. Then, when this diode was incorporated into the design of the voltage regulator, the number changed up to 1111678. It's a mystery to me why both the 368 and the 378 both appear in the 1966 and 1967 P&A30's. Neither of these TI volt reg's are fully transistorized units; the field relay remains electro-mechanical.

[Loren L.]

The last sentence seems to imply that the

"368" and "378" were "replacement" of the "515". The "378" WAS NEVER
used for anything other than service. I believe that the "515" (after 1965) may have appeared as serive and perhaps production in some of the "shark" years.

[Joe L.]

Re: IMO, Only 1965 w/C60 and K66

Wayne-----

To be honest, I thought that 1965 was the only year of their use on Corvettes. It's certainly the only year that I have ever seen them on. While I've never seen one on a 1966 Corvette, I've not seen every 1966 Corvette ever built with SHP, TI and A/C. So, I simply reported what GM says in the case of 1966. Somehow, I feel that they've got to be given their due; they designed and built the cars and had "hands on" experience with every single one.

[Jack H.]

Re: The last sentence seems to imply that the

That's why I said Delco Remy 'featured' the SS voltage regulators in their SERVICE REPLACEMENT catalogs, Loren. Apparently, Delco wanted to 'drum' sales for the unit that was only being used by producing divisions in limited applications. This might well have been a vehicle unit cost consideration...

The SS v-reg (with the correct PN) is indeed a functional, drop-in, replacement for the familiar '515 electro mechanical regulator. And, YES, the 515 continued to be used on Corvette until the v-reg function went solid-state and was moved inside the alternator in 1969. But, Chevy passenger cars continued to use the old '515 WELL into the early 70's....

I suspect the move to integrate the v-reg function into the alternator was the reason why we don't see too many of the discrete SS v-reg units out there. That move simplified wiring interconnect + reduced connector count over having separate alternator + voltage regulator components in the vehicle.

[Dick W.]

Re: The last sentence seems to imply that the

The main issue with the electronic regulators was that we, as mechanics and owners, did not understand the importance of good grounds, not using a screwdriver arcing across terminals, etc. The electronics in these early units did not have much in the way of surge protection. In the early '60's DR came out with a solid state regulator for HD trucks, the 9000590 unit. We operated a fleet of 20 trucks with these regulators and had to keep 5 spare regulators. They looked exactly like the TI boxes used on the '64-'71 Corvettes. In fact I have seen a couple of them at swap meets and the vendors were trying to pass them off as TI boxes :D

[Loren L.]

Sorry to rain on your parade but the

368 regulator was the REGULAR PRODUCTION REGULATOR FOR TI & A/C cars in 1965. The 378 was ALWAYS for SERVICE ONLY.