Blower motor no power

[Ciciro]

Thought my motor was cooked so I removed it and hooked it up to a 12v supply and "Thar She Blows"! So I put it back in and pulled the levers to see if it worked and nothing, so out came my test light.First off it's a 76 Targa with no center heater/fan control.I tested the pull lever switches as I was told the motor is controlled ,turned off and on by the switch on the levers and we have power.Double checked fuses in the front compartment and all was good.Moving to the engine compartment I removed my cover and checked the fuses and power back there and it's good at the fuses.Now I read about the relay and how to jump the reed switch but I don't have the controller at all in my engine panel just a regular relay.now I tested the power to the relay and test light works,but when I test for power to the fan/blower I get nothing.So am I missing something or is that the proper set-up for my car and if it is what is my next plan of attack?Where do I go from here?

[timmy2]

If you have power to the relay and it isn't switching the power to the fan then the relay isn't working.
Take out the relay and bench test it by giving it a fused 12 volts to the coil and check for continuity across the open contacts. If they close when you operate the coil then it works.
If not, buy a new relay.

[Ciciro]

I have tested the relay on other circuits and it works also removed my fuel pump relay and tried that and still no power so I'm sure my relay works fine.Now I could cut open my harness on the engine and check the wire all the way to the blower but that will be my last resort.Is there another place that could cause a problem?

[timmy2]

Check for continuity on all wires from relay to blower. Use jumpers as required to check each wire end to end. You may have an open somewhere. Easier than cutting up the harness.
I don't have a schematic wiring diagram for your car or I'd trace it out for you. I have a '69 schematic and a '78.
I just want to be sure, you're talking about the blower in the front of the car? Or do you have one in back?

[timmy2]

Going by the '69 diagram, the Black wire goes from relay terminal 87 to motor terminal 75. The others are from the speed controller. (White, white with Yellow and white with red)

[Ciciro]

It's the rear blower motor that is connected to the heat exchangers in the engine bay.

[timmy2]

OK, Then it should be easy to check the wires to see if one is broken.
Disconnect battery.
The 14 pin engine connector on the left side regulator panel near the relay for your blower is where it connects to the relay. Unplug it and using an ohmmeter see if you can get continuity to the plug from the blower motor plug on both wires at the blower motor end.
If that is good, then check the plug connections at the back of the regulator panel to the pins on the relay plug.
It may just be a bad connection in the engine harness plug or from that plug to the relay plug or even a bad relay connection. Have you spread the relay pins with a razor blade?

[Ciciro]

Yes I did open up the pins ,but I'm thinking that maybe the 14 pin connector may be my next place to test?Any diagram of the 14 pin connector and its pin out?On both the male and female side?I'll check my diagrams and try to find out,Thanks for the help I'll try to tackle it in the next few days..

[Ciciro]

Actually I'm downloading a 2.7L workshop manual now and will check it out there..If I have any troubles I'll be back on to look for more help...

[john walker's workshop]

the contacts under the red levers need to touch and complete the ground to the relay. fuzz removal and maybe some light tweeking is the usual fix. jump the 30 and 87 terminals in the relay plug to give direct 12V to the fan, just to see if the wiring in that section is OK.

[timmy2]

Following John's lead, You said you had power at the lever switches. Both sides of each switch? If you measure voltage from one side of the swith to the other then the contacts are open. If no volts across switch it is closed.

[Ciciro]

Tested power at the switch and cleaned the contacts,and yes a little tweaking of the contacts to insure they touched when moved to the heated position on the levers. I will try the jumper between 30 and 87. Love a pin out diagram of the 14 pin connector to check if that's the issue.

[Ciciro]

problem with that dia. is I don't have the engine heater controller in my car and also no center tunnel control switch.I have those dia. also.May have to look at it a bit closer to figure it out.

[Ciciro]

Okay, found 14 pin diagram and tested it and no power to pin 13..So I decided to jumper 30 and 87 on the relay and success,Thanks John Walker..tested the relay and it was fine so cleaned up the contacts and spread them a bit open and tried again and finally it works.Now I still have minimal heat blowing into the car so rolled around on the ground to see if the heat exchangers were closing to insure full flow to the car and they were 98% closed,tried to tinker and adjust them but it was a bit hard without lifting up the car but closed them.Now still not a lot of heat blowing threw the defrost vent.Any suggestions?

[timmy2]

Originally Posted by Ciciro

Okay, found 14 pin diagram and tested it and no power to pin 13..So I decided to jumper 30 and 87 on the relay and success,Thanks John Walker..tested the relay and it was fine so cleaned up the contacts and spread them a bit open and tried again and finally it works.Now I still have minimal heat blowing into the car so rolled around on the ground to see if the heat exchangers were closing to insure full flow to the car and they were 98% closed,tried to tinker and adjust them but it was a bit hard without lifting up the car but closed them.Now still not a lot of heat blowing threw the defrost vent.Any suggestions?

Move to a warmer climate...
Seriously though, I'm glad you found the problem, make sure you aren't mixing outside air with the defrost. On my car I push the dash control center lever all the way to the left to close off outside air.
Are there any holes/leaks in the engine ductwork from the fan to the exchangers? Are you driving on the highway at 3000+ rpm to get the temps up? Should be lots of heat.
I backdated my exhaust system and removed the engine blower. I have to push my red floor levers almost off to not get cooked in my Targa.

[Ciciro]

Duct work is relatively new.Just had the engine put in this summer.I just ran it and held the idle around 2500 rpm.Guess I'm expecting free flowing heat when its not moving,to used to newer cars,it's been too long since I've actually gone on long rides with it and really haven't yet,to many minor issues to deal with first.Guess I'll wait to see one dry warmer day.It's raining pretty good today so in the garage it stays.Next project is to wire up power mirrors on both sides.Drivers side worked when I got the car 20 years ago but found out passenger wires weren't there.So I bought a harness,just need the switch for the dash and a diagram of where the wires go and I'll be set.It doesn't look to fun getting the wires into the doors.