WHEN did the battery change in 80s T.C.s ?

[Gerald F. Chase]

I had been led to believe from some place that I cannot now recall, the it was with the 1989 model that the Town Car battery was changed, from having the positive post near the right front fender to the inboard side, near the radiator.

However, I just discovered that my '88 TC has the positive terminal near the radiator, whereas with my '85, the positive post of the battery is on the outboard side, near the fender.

Was this a mid-year change, or was the change starting with the '88 models?

Forgetting where the 302's starter is for the moment, was this change made to SHORTEN one of the cable lengths, in comparison to the other.... figuring that total voltage drop is affected by BOTH cable lengths? Or, might the change been made for cable length reasons from the starter solenoid ? Are there any electrical engineers here that are qualified to render a judgment??

Finally, does anyone think there is a good reason to change a given TC to the later, or earlier, battery cable layout?

[LithiumCobalt]

If I recall, '88 was the year of the change. The battery group changed from group 56 to 65 or something like that. Different dimensions. My '87 had the group 56.

[Gerald F. Chase]

OK, Nick; thanks for the input. And, man, that was the fastest response ever! From my research today, the change did indeed occur after the end of the '87 production, at the beginning of the '88 TC production.

What I've discovered from one supplier of new battery cables, STANDARD Motor Products, their ground cable for an '88 TC is only 6 gauge, whereas the other two cables for an '88 TC are 4 gauge. This doesn't make any sense in my book. "The chain is only as strong as its weakest link", right?

NAPA offers two negative cables for this application, but neither one has the small auxiliary lead from the clamp that the one from Standard has. The other thing is that one has a red rubber covering, and the other is black. Both are the preferable 4 gauge, but the black one is 45% more money. Beats me why.

EXIDE offers two choices of negative battery cables: a 6-gauge (w/ aux. lead), and a 4-gauge. (just like Standard). The goofy thing is that the 6-ga. one is at least half again more money. Go figure.

DEKA offers two negative battery cables for this application: though both are 4 gauge (one slightly longer than the other), neither has an auxiliary lead. (just like NAPA)

What to do, short of dropping big bucks for a custom creation? I just want a four-gauge negative cable with an auxiliary lead, and about 33 - 34 inches long. Comments or advice?

[Gerald F. Chase]

I notice the dimensions and the CCA for a Group 65 battery (specified for '88 & '89 TCs) is significantly greater than for the Group 56 (specified for '80 - '87 TCs). So are the warranties.

Given that the physical area (and maybe the battery tray) is probably similar in size between the '88 & '89 TCs versus the '80 - '87 TCs.... doesn't it make more sense to install a Group 65 in a pre-'88 TC... and simply install new cables, if necessary? The posts in opposite locations can be overcome this way, if need be.

Who wouldn't want greater output and reserve in their car battery?

[LithiumCobalt]

There's many that have swapped the batteries to the newer group 65. Grab a tray from a '88 or '89 and you're in business. I was considering doing such a thing with my '87, but the car was an untouched original and I didn't want to make it "non-stock" so I left it be. For a non show car used as maybe a daily driver, no reason not to upgrade.

[Gerald F. Chase]

Nick, Your reasoning reflects mine, and I agree. I didn't realize that I'd need a later "tray", though.

[Gerald F. Chase]

The battery tray in my '88 looks suspiciously like one from the '80 - '87 period.... so I must pull the battery out of my '85 next week to measure its tray, for comparison.

I have no reason or suggestive evidence that the tray in my '88 is anything but stock. Yet I notice the slight
"ridge" at the forward side (laterally) is only 6.1" from the rearward lateral of the tray. This lines up with the width dimension of a group 56. Hmm-m-m. Said forward ridge doesn't still up much, fortunately.

I'll be able to make the group 65 fit in the '88. It didn't come with a hold-down assembly, so that's an item I need to obtain and install. Is the hold-down assembly different for the '88 & '89, versus the earlier ones?

BTW, how many auxiliary wires emanate from stock negative battery cable terminal at the battery? I've got two auxiliary wires on my '88s non-stock battery terminal. One goes to the header panel, as an extra ground. I don't know where the other one goes, or for what equipment its for. Does anyone know?