Drewvious

Hello all, I tried a few of the old threads about testing the blower motor etc. I have one that is baffling for me. If I unplug the top plug on the relay under the hood (three prong), I hear an audible click when going to and from high. If I plug in the top with the three prong connector, I get a noise out of the relay reminiscent of the game "Operation". Needless to say, the blower does not come on. Bad blower motor grounding out? Looking for suggestions. Thanks in advance.

0Willcox Corvette

Run 12 volts to the blower motor direct.. see if it blows. If it does great, research further and if it fails then run a test ground to the motor and try again.. If it fails again the issue is the motor.

But.. From what you describe it sounds like a failing relay.. So if it were me I'd pry open the relay, file the contacts and then try the system again. If you still have the buzzing sound then I'd replace the relay.

If you go to our youtube page and search wiper motor relay you'll find out how to fix a burnt relay contact set.

Willcox

Here is a basic schematic of the system.

Drewvious

When I try to put 12 volts straight to the purple coming from the blower motor I am basically arc welding with the wire when it touches. Blower motor seems to be grounding itself at the windings is my best guess.. What do you think? That is not what my relay looks like however, the one in your diagram.

0Willcox Corvette

There was an early version of that relay but it functions in the same manner. Pull the purple from the blower motor and apply 12 volts straight to the motor and see if it arc's... if it does then you need a motor.

terry82

the motors are cheap. replace it and add another ground wire .

Drewvious

Hey guys, thanks for the suggestions. It seems I had several issues. I have replaced the blower motor, it was indeed bad. It also appears that the relay is bad as well, I'll include a picture of the relay. Any idea of the part number for the relay? Everywhere I look for the 79 blower motor relay it is the one in the Wilcox diagram. I'm getting 12 volts on all relay spades minus the ground as well as all four of the resistors below the relay with the speed on low. Would a faulty relay cause this? The other odd thing is that when I run a ground to the blower motor directly, with key off, the motor comes on. seems confusing to me..

terry82

if your blower motor(with key off ) runs when you put on a ground wire ,,,, my thought would be that it was not grounded very well to begin with.replace relay and see what you have then .I would put a test light on the blower motor hot wire connector and see what happens when you change blower speeds after you replace relay.

0Willcox Corvette

I have the relay in stock.. but why not unbend those tabs and clean the contacts on the one you have.. they are easy to rebuild. Go to my tech page and watch the video on the wiper relay's.... the rebuild is the same and pretty dang easy.

If the electromagnet is working then you can fix this for free.. If the magnet isn't working then give me a ring and I'll get one on the way to you.

Willcox

'75

Here's a possibility. There is a small black wire that should be grounded near the starter, on a bell housing bolt maybe. Sometimes that ground wire mistakenly gets hooked up to the big battery lug at the starter. That ground wire is for the blower motor and a couple other things. It's easy to check and could clear up this whole problem.

Drewvious

Thanks for all of the help guys. I ended up finding that the motor was indeed bad as well as the relay. I took the relay apart and there seemed to be an issue with the electromagnet, contacts were clean. Everything is great now except for the high setting on the switch, I'll track this down later this week. Thanks again!

0Willcox Corvette

High speed is the orange wire direct from the blower switch.. So when you are in high speed you should have power on that orange wire going into the relay.

It's very common for the connector that plugs into the relay to melt due to heat from the exhaust. So check the terminal in the connector and make sure it's A) snug in the connector and B) not corroded due to being loose..

If you need that connector I've got like 500 of them too..

Willcox

Drewvious

I don't know your first name so I'll just call you Wilcox. I've spent thousands with Ecklers over the last couple months and would gladly use you instead. I noticed I can't PM you, is your website the best way to reach you? I have a lot more to buy coming up for the winter projects on the Vette.

0Willcox Corvette

The best way is to call Tommy 812-288-7103, 800-588-3883, if you need help finding parts or email him at at Sales@Willcoxcorvette.com.

If you have a list of parts you need, email it and if you need technical assistance beyond what this forum offers then email me at support@Willcoxcorvette.com I don't work in sales so I'm never in the parts store.

Willcox