Connected Battery Backwards - Now Buick Won't Start - What Have I Done?

[TxBuicks]

I took the battery out of my 1970 Riviera to charge it up. After a full charge I put it back in but connected the terminals backwards. I didn't know it until I tried to start it. Of course, nothing happened when I turned on the ignition. Even after I fixed the connections, nothing happens. No sounds of any kind, no dash lights, no accessories, nothing. The only thing I have is headlights. The shop manual says extensive electrical system damage can happen when the connections are backwards but it doesn't tell specifics. I didn't smell any burning wires nor do I see any burnt wires.

I checked the fuse panel, only to discover two of the fuses had been replaced with copper tubes by the previous owner. I replaced those fuses. I bought a new voltage regulator, but it made no difference. The guy at NAPA said it could be the igition switch. Has anyone else been so stupid to do this? Any ideas? Where do I start looking? Any logical advice would be appreciated. Thanks.

[JohnD1956]

Roy, sounds like you may have got very lucky, and blown a fusible link. I believe one of the two links is just for the headlights. The other is for everything else. I would start by hooking the battery up with a quick disconnect on the negative terminal. Then use a meter ( a simple volt meter is okay) to check if you have power to the fuse box for any of the electrical items.

[60FlatTop]

Guess how stupid I was! And it could be genetic. An couple generations ago the Daily's, Faries, and Coffey's were all related in Rochester, New York; check the family tree.

I had a positive ground 1935 Nash Twin Six Ambassador Victoria 2 door sedan. In the winter the battery went dead so I inadvertently recharged it backwards. Everything seemed fine until I noticed the amp gauge went to discharge when I revved the engine. I called an electrical engineer friend who told me it would be very hard to do that..... but if anyone could he suspected it would be me. He recommended I drain the battery to an equally "flat" condition and recharge it correctly. He was skeptical.

I hooked the fan from an old dash mounted heater to the battery with vise grips on the wires and sucked all the juice from the battery. Then recharged it positive to positive. Everything restored to original and I think the battery lasted another four or five years. And I sold the heater on Ebay!

You learn stuff working on cars.

Bernie

[TxBuicks]

John, I don't think I have power to the fuse box. Where are these fusible links?

[NTX5467]

One fusible link will be in the starter wiring. It'll look like normal wire, but will have a generally softer feel to it (with a "grainier" insulator appearance) AND be attached with some larger-diameter "sections" (usually about 1"+ in length and close to 1/2" in diameter.

If the headlights work, but not the ignition, then you might need to trace the IGN lead to the switch and then backward to the bulkhead connector (both sides) and then to the battery source. If the prior owner had some "tubes" in place of fuses, there might be some other "tricks" he used, too.

Please keep us posted on your progress!

NTX5467

[JohnD1956]

Roy, on my 69, both fusible links are attached to the terminal on the starter solenoid with the battery cable.

[TxBuicks]

Thanks for the suggestions. Looks like I'll be jacking it up and looking at the wires going to the starter.

[Guest shadetree77]

Whew. You got lucky Roy! I hooked up the battery backwards on an '89 Cadillac DeVille I had one time and within 10 seconds of hooking it up I began to hear a sizzling and popping noise. I looked up to see the alternator....ON FIRE! I quickly realized my mistake and pulled the negative cable. The fire went out but it was too late though. My alternator was literally FRIED. Lucky for me it stopped at the alternator for some reason. I got the alt. rebuilt at a local shop and the car ran just fine. Kind of weird that no fuses or fusible links caught it before it hit the alternator. Anyway, don't feel too bad. It happens. Good luck finding the problem.

[Joseph P. Indusi]

Hooking up the battery backwards will usually burn out the diodes in the alternator although your car may have saved it by virtue of the fusible links. I am not familiar with the wiring diagram on your car, but checking the fusible links is a good way to proceed.

Joe, BCA 33493

[TxBuicks]

The shop manual mentions that the diodes of the alternator could be destroyed. I took it to NAPA and had it tested and they said it was bad, but I didn't have full confidence in their analysis. They didn't seem to know how to run the testing device. I brought it back home but haven't installed it back yet. It could be bad. But, even if it is bad, I don't think it would cause the sympthoms I am seeing. Would it?

I have the shop manual, with a wiring diagram. Would the fusible links be shown in the diagram? Do you think they would be between the alternator and the starter? Or the starter and the igition switch? I am just trying to narrow down the possibilities without having to inspect every wire.

Thanks.

[Roadmaster75]

Tx,

I have a 1970 Buick shop manual here and on page 120-7 it clearly explains your car's TWO fusible links;

down at the starter. There are two red wires a number 10 & a Number 12. The 12 goes through the bulhead connector to the headlights

The number 10 goes upstream and spliced to feed the ALT & Ign switch. See page 68-14.

On 120-7:

It states " Burned out fusible link would indicated by:"

1.) ALL electrical accessories dead except headlights OR headlights dead and all others working

2.) Starter dead ..... possibly due to fusible link

3.) They explain a test using a test light or meter while turning the blower motor on high and

taking a reading at the alternator's RED wire (Number 10) . If battery voltage is present OR the test light lights

brightly...you have a burned out fusible link.

You can buy new fusible links readily from the auto parts store; but you MUST solder them in

properly ... not just a crimp job. DISCONNECT Battery FIRST!

The most likely problem is probably these links. A simple visual check under there and a test light or meter in hand

will tell all (simple continuity check from starter end upstream to the other end of the link would be a good start.

...... do this before you start replacing alternators, etc.

[TxBuicks]

Roadmaster75, I have a 1970 Shop manual and I have read the sections on starter and ignition but never read the sections you mentioned. That sounds like EXACTLY what I was looking for. You make it sound so simple. I have both a test light and meter so now I know where to look. Thank you all very much.

[TxBuicks]

It is running again! It was definately the fusible link by the starter, exactly like Roadmaster75 said. It was obvious when I saw that the wire had burned in two. Once I knew where to look it was an easy fix. Thanks, again, to everyone for all the suggestions.

[Roadmaster75]

A good result, Roy!

Glad the Riv is on the road again....!

Now go enjoy driving it .... it's still snowy, sloppy, and salty here

so all the cars must stay inside......

mike